TY  - JOUR
AU  - Veljić, Darko
AU  - Rakin, Marko
AU  - Sedmak, Aleksandar
AU  - Radović, Nenad
AU  - Međo, Bojan
AU  - Mrdak, Mihailo
AU  - Bajić, Darko
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6008
AB  - This paper deals with analysis and comparison of the equivalent plastic strain and temperature fields in the aluminium alloy 2024 T3 welded joint, with macro/microstructure appearance and hardness profile. In the alloys hardened by heat treatment, grain size and particle size of the precipitate are functions of equivalent plastic strain, strain rate and temperature. By analyzing the equivalent plastic strain fields and temperature fields it is possible, to some extent, to capture the effect of welding parameters and thermo-mechanical conditions on grain structure, and therefore hardness and strength in the welded joint. A coupled thermo-mechanical model is applied to study the material behaviour during the linear welding stage of friction stir welding (FSW). Three-dimensional finite element (FE) model has been created in ABAQUS/Explicit software using the Johnson-Cook material law. The values of thermo-mechanical quantities during the welding stage are obtained from the numerical model and shown as distributions across the joint. The obtained values of these quantities are related to the microstructure of the joint zones and hardness distribution, and this relation is discussed.
PB  - VINČA Institute of Nuclear Sciences
T2  - Thermal Science
T1  - Influence of temperature and plastic deformation on AA2024 T3 friction stir welded joint microstructure
EP  - 320
IS  - 1A
SP  - 311
VL  - 27
DO  - 10.2298/TSCI210216186V
ER  - 

@article{
author = "Veljić, Darko and Rakin, Marko and Sedmak, Aleksandar and Radović, Nenad and Međo, Bojan and Mrdak, Mihailo and Bajić, Darko",
year = "2023",
abstract = "This paper deals with analysis and comparison of the equivalent plastic strain and temperature fields in the aluminium alloy 2024 T3 welded joint, with macro/microstructure appearance and hardness profile. In the alloys hardened by heat treatment, grain size and particle size of the precipitate are functions of equivalent plastic strain, strain rate and temperature. By analyzing the equivalent plastic strain fields and temperature fields it is possible, to some extent, to capture the effect of welding parameters and thermo-mechanical conditions on grain structure, and therefore hardness and strength in the welded joint. A coupled thermo-mechanical model is applied to study the material behaviour during the linear welding stage of friction stir welding (FSW). Three-dimensional finite element (FE) model has been created in ABAQUS/Explicit software using the Johnson-Cook material law. The values of thermo-mechanical quantities during the welding stage are obtained from the numerical model and shown as distributions across the joint. The obtained values of these quantities are related to the microstructure of the joint zones and hardness distribution, and this relation is discussed.",
publisher = "VINČA Institute of Nuclear Sciences",
journal = "Thermal Science",
title = "Influence of temperature and plastic deformation on AA2024 T3 friction stir welded joint microstructure",
pages = "320-311",
number = "1A",
volume = "27",
doi = "10.2298/TSCI210216186V"
}

Veljić, D., Rakin, M., Sedmak, A., Radović, N., Međo, B., Mrdak, M.,& Bajić, D.. (2023). Influence of temperature and plastic deformation on AA2024 T3 friction stir welded joint microstructure. in Thermal Science
VINČA Institute of Nuclear Sciences., 27(1A), 311-320.
https://doi.org/10.2298/TSCI210216186V

Veljić D, Rakin M, Sedmak A, Radović N, Međo B, Mrdak M, Bajić D. Influence of temperature and plastic deformation on AA2024 T3 friction stir welded joint microstructure. in Thermal Science. 2023;27(1A):311-320.
doi:10.2298/TSCI210216186V .

Veljić, Darko, Rakin, Marko, Sedmak, Aleksandar, Radović, Nenad, Međo, Bojan, Mrdak, Mihailo, Bajić, Darko, "Influence of temperature and plastic deformation on AA2024 T3 friction stir welded joint microstructure" in Thermal Science, 27, no. 1A (2023):311-320,
https://doi.org/10.2298/TSCI210216186V . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Bajić, Darko
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6334
AB  - Zirconium dioxide ZrO2 is used as a basic material for thermal barriers and as a biomaterial for manufacturing parts for hip implants in orthopedic surgery and in dentistry for making crowns. Use of ZrO2 ceramics as an insulating material and biomaterial is due to its good chemical and dimensional stability, mechanical strength, toughness and elastic modulus. The aim of this study was to analyze the characteristics of zirconium oxide coating of stabilized cerium and yttrium oxide deposited by atmospheric plasma spraying (APS) process on the bond coating of nickel chromium cobalt yttrium oxide. Coatings were deposited on cold substrates and on substrates preheated to 180°C. Composite powder nickel chromium/aluminum/cobalt/yttrium oxide was used for the production of bond layers and for the ceramic layers zirconium oxide stabilized with cerium and yttrium oxide powder. Testing the quality of coatings was done by measuring microhardness of layers using the HV method and for bond tensile strength of the coating system tensile testing was applied. Metallographic evaluation of the share of pores in the bond and ceramic layers was performed with image analysis-processing of images from a light microscope. Powder particle morphology and EDS analysis were performed on the SEM. The obtained results confirm that the preheating temperature of the substrate has a significant impact on structural mechanical properties of the tested coatings system.
AB  - Cirkonijum dioksid ZrO2 se koristi kao osnovni materijal za izradu termalnih barijera i kao
biomaterijal za izradu delova implanata kuka u ortopedskoj hirurgiji i u stomatologiji za izradu
kruna. Korišćenje ZrO2 keramičke kao izolacionog i biomaterijala je njena dobra hemijska i
dimenzionalna stabilnost, mehanička čvrstoća, žilavost i modul elastičnosti. Cilj rada bio je da se
analiziraju karakteristike prevlake cirkonijum oksida stabilizovanog cerijum i itrijum oksidom
deponovane plazma sprej (APS) postupkom na veznoj prevlaci nikl hrom aluminijum kobalt itrijum
oksid. Prevlake su deponovane na hladnim substratima i na predgrejanim substratima na
temperaturi 180 °C. Za izradu veznih slojeva primenjen je kompozitni prah nikl
hrom/aluminijum/kobalt/itrijum oksid, a za izradu keramičkih slojeva prah cirkonijum oksida
stabilizovanog cerijum i itrijum oksidom. Ispitivanje kvaliteta prevlaka je urađena merenjem
mikrotvrdoće slojeva metodom HVi zatezne čvrstoće spoja sistema prevlaka ispitivanjem na
zatezanje. Metalografska procena udela pora u veznim i keramičkim slojevima je urađena image
analizom - obradom slika sa svetlosnog mikroskopa. Morfologije čestica prahova i EDS analiza je
urađena na SEM-u. Dobijeni rezultati potvrđuju da temperatura predgrevanja substrata ima bitan
uticaj na strukturno mehanička svojstva testiranih sistema prevlaka.
PB  - Engineers Society for Corrosion
T2  - Materials Protection
T1  - Characterization of zirconium oxidecoating stabilized with cerium and yttrium oxide deposited on the bonding coating nickel chromium aluminum cobalt yttrium oxide
T1  - Karakterizacija prevlake cirkonijum oksida stabilizovanog cerijum i itrijum oksidom deponovane na veznoj prevlaci nikl hrom aluminijum kobalt itrijum oksid
EP  - 12
IS  - 1
SP  - 5
VL  - 64
DO  - 10.5937/zasmat2301005M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Bajić, Darko",
year = "2023",
abstract = "Zirconium dioxide ZrO2 is used as a basic material for thermal barriers and as a biomaterial for manufacturing parts for hip implants in orthopedic surgery and in dentistry for making crowns. Use of ZrO2 ceramics as an insulating material and biomaterial is due to its good chemical and dimensional stability, mechanical strength, toughness and elastic modulus. The aim of this study was to analyze the characteristics of zirconium oxide coating of stabilized cerium and yttrium oxide deposited by atmospheric plasma spraying (APS) process on the bond coating of nickel chromium cobalt yttrium oxide. Coatings were deposited on cold substrates and on substrates preheated to 180°C. Composite powder nickel chromium/aluminum/cobalt/yttrium oxide was used for the production of bond layers and for the ceramic layers zirconium oxide stabilized with cerium and yttrium oxide powder. Testing the quality of coatings was done by measuring microhardness of layers using the HV method and for bond tensile strength of the coating system tensile testing was applied. Metallographic evaluation of the share of pores in the bond and ceramic layers was performed with image analysis-processing of images from a light microscope. Powder particle morphology and EDS analysis were performed on the SEM. The obtained results confirm that the preheating temperature of the substrate has a significant impact on structural mechanical properties of the tested coatings system., Cirkonijum dioksid ZrO2 se koristi kao osnovni materijal za izradu termalnih barijera i kao
biomaterijal za izradu delova implanata kuka u ortopedskoj hirurgiji i u stomatologiji za izradu
kruna. Korišćenje ZrO2 keramičke kao izolacionog i biomaterijala je njena dobra hemijska i
dimenzionalna stabilnost, mehanička čvrstoća, žilavost i modul elastičnosti. Cilj rada bio je da se
analiziraju karakteristike prevlake cirkonijum oksida stabilizovanog cerijum i itrijum oksidom
deponovane plazma sprej (APS) postupkom na veznoj prevlaci nikl hrom aluminijum kobalt itrijum
oksid. Prevlake su deponovane na hladnim substratima i na predgrejanim substratima na
temperaturi 180 °C. Za izradu veznih slojeva primenjen je kompozitni prah nikl
hrom/aluminijum/kobalt/itrijum oksid, a za izradu keramičkih slojeva prah cirkonijum oksida
stabilizovanog cerijum i itrijum oksidom. Ispitivanje kvaliteta prevlaka je urađena merenjem
mikrotvrdoće slojeva metodom HVi zatezne čvrstoće spoja sistema prevlaka ispitivanjem na
zatezanje. Metalografska procena udela pora u veznim i keramičkim slojevima je urađena image
analizom - obradom slika sa svetlosnog mikroskopa. Morfologije čestica prahova i EDS analiza je
urađena na SEM-u. Dobijeni rezultati potvrđuju da temperatura predgrevanja substrata ima bitan
uticaj na strukturno mehanička svojstva testiranih sistema prevlaka.",
publisher = "Engineers Society for Corrosion",
journal = "Materials Protection",
title = "Characterization of zirconium oxidecoating stabilized with cerium and yttrium oxide deposited on the bonding coating nickel chromium aluminum cobalt yttrium oxide, Karakterizacija prevlake cirkonijum oksida stabilizovanog cerijum i itrijum oksidom deponovane na veznoj prevlaci nikl hrom aluminijum kobalt itrijum oksid",
pages = "12-5",
number = "1",
volume = "64",
doi = "10.5937/zasmat2301005M"
}

Mrdak, M., Lačnjevac, Č.,& Bajić, D.. (2023). Characterization of zirconium oxidecoating stabilized with cerium and yttrium oxide deposited on the bonding coating nickel chromium aluminum cobalt yttrium oxide. in Materials Protection
Engineers Society for Corrosion., 64(1), 5-12.
https://doi.org/10.5937/zasmat2301005M

Mrdak M, Lačnjevac Č, Bajić D. Characterization of zirconium oxidecoating stabilized with cerium and yttrium oxide deposited on the bonding coating nickel chromium aluminum cobalt yttrium oxide. in Materials Protection. 2023;64(1):5-12.
doi:10.5937/zasmat2301005M .

Mrdak, Mihailo, Lačnjevac, Časlav, Bajić, Darko, "Characterization of zirconium oxidecoating stabilized with cerium and yttrium oxide deposited on the bonding coating nickel chromium aluminum cobalt yttrium oxide" in Materials Protection, 64, no. 1 (2023):5-12,
https://doi.org/10.5937/zasmat2301005M . .

TY  - JOUR
AU  - Veljić, Darko M.
AU  - Rakin, Marko P.
AU  - Sedmak, Aleksandar S.
AU  - Radović, Nenad A.
AU  - Međo, Bojan I.
AU  - Mrdak, Mihailo R.
AU  - Bajić, Darko R.
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5152
AB  - The influence of friction stir welding parameters on thermo-mechanical behavior of the material during welding is analyzed. An aluminum alloy is considered (Al 2024 T351), and different rotating and welding speeds are applied. The finite element model consists of the working plate (Al alloy), backing plate and welding tool. The influence of the welding conditions on material behavior is taken into account the application of the Johnson-Cook material model. The rotation speed of the tool affects the results. If increased, it contributes to an increase of friction-generated heat intensity. The other component of the generated heat, which stems from the plastic deformation of the material, is negligibly changed. When the welding speed, i.e. tool translation speed, is increased, the intensity of friction-generated heat decreases, while the heat generation due to plastic deforming is becoming more pronounced. Summed, this leads to rather small change of the total generation. The changes of the heat generation influence both the temperature field and reaction force. Also, the inadequate selection of welding parameters resulted in occurrence of the defects (pores) in the model.
PB  - VINČA Institute of Nuclear Sciences
T2  - Thermal Science
T1  - Thermo-mechanical analysis of linear welding stage in friction stir welding Influence of Welding Parameters
EP  - 2134
IS  - 3A
SP  - 2125
VL  - 26
DO  - 10.2298/TSCI210216186V
ER  - 

@article{
author = "Veljić, Darko M. and Rakin, Marko P. and Sedmak, Aleksandar S. and Radović, Nenad A. and Međo, Bojan I. and Mrdak, Mihailo R. and Bajić, Darko R.",
year = "2022",
abstract = "The influence of friction stir welding parameters on thermo-mechanical behavior of the material during welding is analyzed. An aluminum alloy is considered (Al 2024 T351), and different rotating and welding speeds are applied. The finite element model consists of the working plate (Al alloy), backing plate and welding tool. The influence of the welding conditions on material behavior is taken into account the application of the Johnson-Cook material model. The rotation speed of the tool affects the results. If increased, it contributes to an increase of friction-generated heat intensity. The other component of the generated heat, which stems from the plastic deformation of the material, is negligibly changed. When the welding speed, i.e. tool translation speed, is increased, the intensity of friction-generated heat decreases, while the heat generation due to plastic deforming is becoming more pronounced. Summed, this leads to rather small change of the total generation. The changes of the heat generation influence both the temperature field and reaction force. Also, the inadequate selection of welding parameters resulted in occurrence of the defects (pores) in the model.",
publisher = "VINČA Institute of Nuclear Sciences",
journal = "Thermal Science",
title = "Thermo-mechanical analysis of linear welding stage in friction stir welding Influence of Welding Parameters",
pages = "2134-2125",
number = "3A",
volume = "26",
doi = "10.2298/TSCI210216186V"
}

Veljić, D. M., Rakin, M. P., Sedmak, A. S., Radović, N. A., Međo, B. I., Mrdak, M. R.,& Bajić, D. R.. (2022). Thermo-mechanical analysis of linear welding stage in friction stir welding Influence of Welding Parameters. in Thermal Science
VINČA Institute of Nuclear Sciences., 26(3A), 2125-2134.
https://doi.org/10.2298/TSCI210216186V

Veljić DM, Rakin MP, Sedmak AS, Radović NA, Međo BI, Mrdak MR, Bajić DR. Thermo-mechanical analysis of linear welding stage in friction stir welding Influence of Welding Parameters. in Thermal Science. 2022;26(3A):2125-2134.
doi:10.2298/TSCI210216186V .

Veljić, Darko M., Rakin, Marko P., Sedmak, Aleksandar S., Radović, Nenad A., Međo, Bojan I., Mrdak, Mihailo R., Bajić, Darko R., "Thermo-mechanical analysis of linear welding stage in friction stir welding Influence of Welding Parameters" in Thermal Science, 26, no. 3A (2022):2125-2134,
https://doi.org/10.2298/TSCI210216186V . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Bajic, Darko
AU  - Veljić, Darko
AU  - Rakin, Marko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4780
AB  - In this paper we will describe the process of the deposition of thick layers of VPS-Ti coating, which is used as a bonding layer for the upper porous Ti coatings on implant substrates. In order to deposit the powder, we used HoGANaS Ti powder labelled as AMPERIT 154.086-63 mu m. In order to test the mechanical properties and microstructure of the VPS-Ti coating, the powder was deposited on C 4171 (X15Cr13 EN10027) steel substrates. Mechanical tests of the microhardness of the coating were per-formed by the Vickers hardness test method (HV0.3) and tensile strength by measuring the force per unit area (MPa). The micro-hardness of the coating is 159 HV0.3, which is consistent with the microstructure. The coating was found to have a good bond strength of 68 MPa. The morphology of the powder particles was examined on a scanning electron microscope. The microstructure of the coating, both when deposited and etched, was examined with an optical microscope and a scanning elec-tron microscope. By etching the coating layers, it was found that the structure is homogeneous and that it consists of a mixture of low-temperature and high-temperature titanium phases (alpha-Ti + beta-Ti). Our tests have shown that the deposited layers of Ti coating can be used as a bonding layer for porous Ti coatings in the production of implants.
T2  - Materiali in Tehnologije
T1  - Characterisation of biomedical titanium layers deposited by a vacuum plasma spray process
EP  - 236
IS  - 2
SP  - 231
VL  - 55
DO  - 10.17222/mit.2020.135
ER  - 

@article{
author = "Mrdak, Mihailo and Bajic, Darko and Veljić, Darko and Rakin, Marko",
year = "2021",
abstract = "In this paper we will describe the process of the deposition of thick layers of VPS-Ti coating, which is used as a bonding layer for the upper porous Ti coatings on implant substrates. In order to deposit the powder, we used HoGANaS Ti powder labelled as AMPERIT 154.086-63 mu m. In order to test the mechanical properties and microstructure of the VPS-Ti coating, the powder was deposited on C 4171 (X15Cr13 EN10027) steel substrates. Mechanical tests of the microhardness of the coating were per-formed by the Vickers hardness test method (HV0.3) and tensile strength by measuring the force per unit area (MPa). The micro-hardness of the coating is 159 HV0.3, which is consistent with the microstructure. The coating was found to have a good bond strength of 68 MPa. The morphology of the powder particles was examined on a scanning electron microscope. The microstructure of the coating, both when deposited and etched, was examined with an optical microscope and a scanning elec-tron microscope. By etching the coating layers, it was found that the structure is homogeneous and that it consists of a mixture of low-temperature and high-temperature titanium phases (alpha-Ti + beta-Ti). Our tests have shown that the deposited layers of Ti coating can be used as a bonding layer for porous Ti coatings in the production of implants.",
journal = "Materiali in Tehnologije",
title = "Characterisation of biomedical titanium layers deposited by a vacuum plasma spray process",
pages = "236-231",
number = "2",
volume = "55",
doi = "10.17222/mit.2020.135"
}

Mrdak, M., Bajic, D., Veljić, D.,& Rakin, M.. (2021). Characterisation of biomedical titanium layers deposited by a vacuum plasma spray process. in Materiali in Tehnologije, 55(2), 231-236.
https://doi.org/10.17222/mit.2020.135

Mrdak M, Bajic D, Veljić D, Rakin M. Characterisation of biomedical titanium layers deposited by a vacuum plasma spray process. in Materiali in Tehnologije. 2021;55(2):231-236.
doi:10.17222/mit.2020.135 .

Mrdak, Mihailo, Bajic, Darko, Veljić, Darko, Rakin, Marko, "Characterisation of biomedical titanium layers deposited by a vacuum plasma spray process" in Materiali in Tehnologije, 55, no. 2 (2021):231-236,
https://doi.org/10.17222/mit.2020.135 . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Janaćković, Đorđe
AU  - Veljić, Darko
AU  - Bajić, Darko
PY  - 2021
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/6035
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5036
AB  - The aim of this study was to deposit multi-functional ZrO28%Y2O3 coating layers using the plasma spray technology and then to characterise such layers. In combination with other biomedical ceramics, this coating is intended for the application in implant surface modification. The examination was focused on the mechanical properties and microstructure layers. Using the atmospheric plasma spraying, duplex ZrO28%Y2O3/Ni22Cr10Al1Y coating system was deposited on the X15Cr13 stainless steel, with two different thicknesses of the bond and ceramic coatings. The microstructure was analysed using an optical microscope, including the assessment of the content of micropores. The morphology of powder particles and ceramic coating surfaces were examined on a scanning electron microscope (SEM). The quality of the ZrO28%Y2O3 layers makes them suitable for the application and combination with other materials to create a system of biomedical or multifunctional coatings.
AB  - Cilj ovog rada bio je da se deponuju višenamenski slojevi prevlake ZrO28%Y2O3 primenom plazma
sprej tehnologije, a zatim da se karakterišu takvi slojevi. U kombinaciji sa drugom biomedicinskom
keramikom, ova prevlaka je namenjena primeni u modifikaciji površine implantata. spitivanje je
bilo usredsređeno na mehanička svojstva i mikrostrukturu slojeva. orišćenjem atmosferskog
plazma spreja, dupleks sistem prevlaka ZrO28%Y2O3 / Ni22Cr10Al1 nanet je na nerđajući čelik
X15Cr13, sa dve različite debljine vezne i keramičke prevlake. ikrostruktura je analizirana
pomoću optičkog mikroskopa, uključujući procenu sadr aja mikro pora. orfologija čestica praha i
površina keramičkih prevlaka ispitivane su na skening elektronskom mikroskopu (SE ). valitet
slojeva ZrO28%Y2O3 čini ih pogodnim za nanošenje i kombinaciju sa drugim materijalima kako bi
se stvorio sistem biomedicinskih ili multifunkcionalnih prevlaka.
PB  - Inženjersko društvo za koroziju
T2  - Zaštita materijala
T1  - Characterisation of biocompatible layers of ZrO28%Y2O used in combination with other ceramics to modify the surface of implants
T1  - Karakterizacija biokompatibilnih slojeva ZrO28%Y2O3 koji se koriste u kombinaciji sa drugom keramikom za modifikaciju površine implantata
EP  - 268
IS  - 4
SP  - 262
VL  - 62
DO  - 10.5937/zasmat2104262M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Janaćković, Đorđe and Veljić, Darko and Bajić, Darko",
year = "2021",
abstract = "The aim of this study was to deposit multi-functional ZrO28%Y2O3 coating layers using the plasma spray technology and then to characterise such layers. In combination with other biomedical ceramics, this coating is intended for the application in implant surface modification. The examination was focused on the mechanical properties and microstructure layers. Using the atmospheric plasma spraying, duplex ZrO28%Y2O3/Ni22Cr10Al1Y coating system was deposited on the X15Cr13 stainless steel, with two different thicknesses of the bond and ceramic coatings. The microstructure was analysed using an optical microscope, including the assessment of the content of micropores. The morphology of powder particles and ceramic coating surfaces were examined on a scanning electron microscope (SEM). The quality of the ZrO28%Y2O3 layers makes them suitable for the application and combination with other materials to create a system of biomedical or multifunctional coatings., Cilj ovog rada bio je da se deponuju višenamenski slojevi prevlake ZrO28%Y2O3 primenom plazma
sprej tehnologije, a zatim da se karakterišu takvi slojevi. U kombinaciji sa drugom biomedicinskom
keramikom, ova prevlaka je namenjena primeni u modifikaciji površine implantata. spitivanje je
bilo usredsređeno na mehanička svojstva i mikrostrukturu slojeva. orišćenjem atmosferskog
plazma spreja, dupleks sistem prevlaka ZrO28%Y2O3 / Ni22Cr10Al1 nanet je na nerđajući čelik
X15Cr13, sa dve različite debljine vezne i keramičke prevlake. ikrostruktura je analizirana
pomoću optičkog mikroskopa, uključujući procenu sadr aja mikro pora. orfologija čestica praha i
površina keramičkih prevlaka ispitivane su na skening elektronskom mikroskopu (SE ). valitet
slojeva ZrO28%Y2O3 čini ih pogodnim za nanošenje i kombinaciju sa drugim materijalima kako bi
se stvorio sistem biomedicinskih ili multifunkcionalnih prevlaka.",
publisher = "Inženjersko društvo za koroziju",
journal = "Zaštita materijala",
title = "Characterisation of biocompatible layers of ZrO28%Y2O used in combination with other ceramics to modify the surface of implants, Karakterizacija biokompatibilnih slojeva ZrO28%Y2O3 koji se koriste u kombinaciji sa drugom keramikom za modifikaciju površine implantata",
pages = "268-262",
number = "4",
volume = "62",
doi = "10.5937/zasmat2104262M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Janaćković, Đ., Veljić, D.,& Bajić, D.. (2021). Characterisation of biocompatible layers of ZrO28%Y2O used in combination with other ceramics to modify the surface of implants. in Zaštita materijala
Inženjersko društvo za koroziju., 62(4), 262-268.
https://doi.org/10.5937/zasmat2104262M

Mrdak M, Lačnjevac Č, Rakin M, Janaćković Đ, Veljić D, Bajić D. Characterisation of biocompatible layers of ZrO28%Y2O used in combination with other ceramics to modify the surface of implants. in Zaštita materijala. 2021;62(4):262-268.
doi:10.5937/zasmat2104262M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Janaćković, Đorđe, Veljić, Darko, Bajić, Darko, "Characterisation of biocompatible layers of ZrO28%Y2O used in combination with other ceramics to modify the surface of implants" in Zaštita materijala, 62, no. 4 (2021):262-268,
https://doi.org/10.5937/zasmat2104262M . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Janaćković, Đorđe
AU  - Veljić, Darko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5118
AB  - In this paper, studied was the melting of W powder particles in plasma, their behavior at oxidation as well as the mechanism of hardening on the surface of the substrate. Tungsten coating layers were deposited with vacuum plasma spray technology (VPS) on the test specimens of steel Č.4171 (X15Cr13 EN10027). VPS technology has advantages over the APS technology due to decreased oxidation of melted powder particles, by producing a coating with a controlled proportion of micro pores and greater uniformity of the deposited layers. Evaluation of mechanical characteristics of the layers was done by examining the microhardness using the HV0.3 method and tensile bond strength by tensile testing. The microstructures of the deposited layers were analyzed by means of optical microscopy (OM) and scanning electron microscopy (SEM). The results obtained showed that the tungsten coating consisted of well melted particles that interconnected and were overlapping, which shows a typical lamellar microstructure. Present in the microstructure are micro pores in very small proportion at the inter-lamellar boundaries. Tests have shown that layers of W coating deposited by plasma spray in inert gas shielding at low pressure have good mechanical properties and microstructure, which in the fully enables its use in exploitation.
AB  - U ovom radu proučavano je topljenje čestica praha W u plazmi, njihovo ponašanje na oksidaciju
kao i mehanizam očvršćavanja na površini substrata. Slojevi volfram prevlake su deponovani sa
vakuum plazma sprej tehnologijom (VPS) na ispitnim uzorcima od čelika Č.4171 (X15Cr13
EN10027). VPS tehnologija ima prednosti u odnosu na APS tehnologiju zbog smanjene oksidacije
istopljenih čestica praha, proizvodeći prevlaku sa kontrolisanim udelom mikro pora i većom
uniformnosti deponovanih slojeva. Procena mehaničkih karakteristika slojeva je urađena
ispitivanjem mikrotvrdoće metodom HV0.3 i zatezne čvrstoće spoja ispitivanjem na zatezanje.
Analizirane su mikrostrukture deponovanih slojeva pomoću optičke mikroskopije (OM) i skening
elektronske mikroskopije (SEM). Dobijeni rezultati su pokazali da se volfram prevlaka sastojala od
dobro istopljenih čestica međusobno povezanih i preklopljenih, koja pokazuje tipičnu lamelarnu
mikrostrukturu. U mikrostrukturi su prisutne mikro pore u veoma malom udelu koje se nalaze na
među-lamelarnim granicama. Ispitivanja su pokazala da slojevi W prevlake deponovani plazma
sprejom u zaštritnoj atmosferi inertnog gasa na niskom pritisku imaju dobre mehaničke osobine i
mikrostrukturu, koje u potpunosti omogućavaju njenu primenu u eksploataciji.
PB  - Inženjersko društvo za koroziju
T2  - Zaštita materijala
T1  - Characterization of vacuum plasma spray VPS - W coating
deposited on stainless steel substrates
T1  - Karakterizacija vakuum plazma sprej VPS - W prevlake deponovane na čeličnim podloga
EP  - 112
IS  - 2
SP  - 106
VL  - 62
DO  - 10.5937/zasmat2102106M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Janaćković, Đorđe and Veljić, Darko",
year = "2021",
abstract = "In this paper, studied was the melting of W powder particles in plasma, their behavior at oxidation as well as the mechanism of hardening on the surface of the substrate. Tungsten coating layers were deposited with vacuum plasma spray technology (VPS) on the test specimens of steel Č.4171 (X15Cr13 EN10027). VPS technology has advantages over the APS technology due to decreased oxidation of melted powder particles, by producing a coating with a controlled proportion of micro pores and greater uniformity of the deposited layers. Evaluation of mechanical characteristics of the layers was done by examining the microhardness using the HV0.3 method and tensile bond strength by tensile testing. The microstructures of the deposited layers were analyzed by means of optical microscopy (OM) and scanning electron microscopy (SEM). The results obtained showed that the tungsten coating consisted of well melted particles that interconnected and were overlapping, which shows a typical lamellar microstructure. Present in the microstructure are micro pores in very small proportion at the inter-lamellar boundaries. Tests have shown that layers of W coating deposited by plasma spray in inert gas shielding at low pressure have good mechanical properties and microstructure, which in the fully enables its use in exploitation., U ovom radu proučavano je topljenje čestica praha W u plazmi, njihovo ponašanje na oksidaciju
kao i mehanizam očvršćavanja na površini substrata. Slojevi volfram prevlake su deponovani sa
vakuum plazma sprej tehnologijom (VPS) na ispitnim uzorcima od čelika Č.4171 (X15Cr13
EN10027). VPS tehnologija ima prednosti u odnosu na APS tehnologiju zbog smanjene oksidacije
istopljenih čestica praha, proizvodeći prevlaku sa kontrolisanim udelom mikro pora i većom
uniformnosti deponovanih slojeva. Procena mehaničkih karakteristika slojeva je urađena
ispitivanjem mikrotvrdoće metodom HV0.3 i zatezne čvrstoće spoja ispitivanjem na zatezanje.
Analizirane su mikrostrukture deponovanih slojeva pomoću optičke mikroskopije (OM) i skening
elektronske mikroskopije (SEM). Dobijeni rezultati su pokazali da se volfram prevlaka sastojala od
dobro istopljenih čestica međusobno povezanih i preklopljenih, koja pokazuje tipičnu lamelarnu
mikrostrukturu. U mikrostrukturi su prisutne mikro pore u veoma malom udelu koje se nalaze na
među-lamelarnim granicama. Ispitivanja su pokazala da slojevi W prevlake deponovani plazma
sprejom u zaštritnoj atmosferi inertnog gasa na niskom pritisku imaju dobre mehaničke osobine i
mikrostrukturu, koje u potpunosti omogućavaju njenu primenu u eksploataciji.",
publisher = "Inženjersko društvo za koroziju",
journal = "Zaštita materijala",
title = "Characterization of vacuum plasma spray VPS - W coating
deposited on stainless steel substrates, Karakterizacija vakuum plazma sprej VPS - W prevlake deponovane na čeličnim podloga",
pages = "112-106",
number = "2",
volume = "62",
doi = "10.5937/zasmat2102106M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Janaćković, Đ.,& Veljić, D.. (2021). Characterization of vacuum plasma spray VPS - W coating
deposited on stainless steel substrates. in Zaštita materijala
Inženjersko društvo za koroziju., 62(2), 106-112.
https://doi.org/10.5937/zasmat2102106M

Mrdak M, Lačnjevac Č, Rakin M, Janaćković Đ, Veljić D. Characterization of vacuum plasma spray VPS - W coating
deposited on stainless steel substrates. in Zaštita materijala. 2021;62(2):106-112.
doi:10.5937/zasmat2102106M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Janaćković, Đorđe, Veljić, Darko, "Characterization of vacuum plasma spray VPS - W coating
deposited on stainless steel substrates" in Zaštita materijala, 62, no. 2 (2021):106-112,
https://doi.org/10.5937/zasmat2102106M . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Janaćković, Đorđe
AU  - Veljić, Darko
AU  - Bajić, Darko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5119
AB  - In this paper, analyzed are the effects of the plasma spray distance on the microstructure and mechanical properties of the NiCrAlCoY2O3 coating layers deposited at atmospheric pressure. The microstructure and mechanical properties of the coating layers are under the influence of the interaction of plasma particles (ions and electrons) with powder particles, providing the transfer of velocity and temperature of the plasma particles onto the powder particles. The effect of the interaction is directly dependent on the time the powder particles were present in the plasma which is defined by distance of the plasma gun from the substrate, depending on the granulation of the powder, the melting point and specific gravity. In order to obtain homogeneous and denser coating layers with high adhesion, in the experiment three distances from the substrate were used: 95 mm, 105 mm and 115 mm. The layers were deposited on thin sheets of AlMg1 aluminum thickness of 0.6 mm. Evaluation of mechanical properties of the layers was carried out by examining microhardness using the HV0.1 method and the bond strength by tensile testing. The morphology of the powder particles was examined on the SEM, while the microstructure of the layers was evaluated under a light microscope in accordance with the Pratt Whitney standard. The results of the experiment showed that the distance from the substrate substantially influenced the structure and mechanical properties of the coating layers. The best deposited layers were examined in the system with the ZrO224%MgO ceramic coating, which have proved to be reliable protectionfrom high temperature and abrasive rocket jet fuel.
PB  - Engineers Society for Corrosion
T2  - Materials Protection
T1  - [Characterization of deposited plasma spray nicralcoy2o3 coating layers on almg1 alloy substrates] [Karakterizacija deponovanih slojeva plazma sprej prevlake nicralcoy2o3 na podlogama od legure almg1]
EP  - 40
IS  - 1
SP  - 34
VL  - 2021
DO  - 10.5937/zasmat2101034M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Janaćković, Đorđe and Veljić, Darko and Bajić, Darko",
year = "2021",
abstract = "In this paper, analyzed are the effects of the plasma spray distance on the microstructure and mechanical properties of the NiCrAlCoY2O3 coating layers deposited at atmospheric pressure. The microstructure and mechanical properties of the coating layers are under the influence of the interaction of plasma particles (ions and electrons) with powder particles, providing the transfer of velocity and temperature of the plasma particles onto the powder particles. The effect of the interaction is directly dependent on the time the powder particles were present in the plasma which is defined by distance of the plasma gun from the substrate, depending on the granulation of the powder, the melting point and specific gravity. In order to obtain homogeneous and denser coating layers with high adhesion, in the experiment three distances from the substrate were used: 95 mm, 105 mm and 115 mm. The layers were deposited on thin sheets of AlMg1 aluminum thickness of 0.6 mm. Evaluation of mechanical properties of the layers was carried out by examining microhardness using the HV0.1 method and the bond strength by tensile testing. The morphology of the powder particles was examined on the SEM, while the microstructure of the layers was evaluated under a light microscope in accordance with the Pratt Whitney standard. The results of the experiment showed that the distance from the substrate substantially influenced the structure and mechanical properties of the coating layers. The best deposited layers were examined in the system with the ZrO224%MgO ceramic coating, which have proved to be reliable protectionfrom high temperature and abrasive rocket jet fuel.",
publisher = "Engineers Society for Corrosion",
journal = "Materials Protection",
title = "[Characterization of deposited plasma spray nicralcoy2o3 coating layers on almg1 alloy substrates] [Karakterizacija deponovanih slojeva plazma sprej prevlake nicralcoy2o3 na podlogama od legure almg1]",
pages = "40-34",
number = "1",
volume = "2021",
doi = "10.5937/zasmat2101034M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Janaćković, Đ., Veljić, D.,& Bajić, D.. (2021). [Characterization of deposited plasma spray nicralcoy2o3 coating layers on almg1 alloy substrates] [Karakterizacija deponovanih slojeva plazma sprej prevlake nicralcoy2o3 na podlogama od legure almg1]. in Materials Protection
Engineers Society for Corrosion., 2021(1), 34-40.
https://doi.org/10.5937/zasmat2101034M

Mrdak M, Lačnjevac Č, Rakin M, Janaćković Đ, Veljić D, Bajić D. [Characterization of deposited plasma spray nicralcoy2o3 coating layers on almg1 alloy substrates] [Karakterizacija deponovanih slojeva plazma sprej prevlake nicralcoy2o3 na podlogama od legure almg1]. in Materials Protection. 2021;2021(1):34-40.
doi:10.5937/zasmat2101034M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Janaćković, Đorđe, Veljić, Darko, Bajić, Darko, "[Characterization of deposited plasma spray nicralcoy2o3 coating layers on almg1 alloy substrates] [Karakterizacija deponovanih slojeva plazma sprej prevlake nicralcoy2o3 na podlogama od legure almg1]" in Materials Protection, 2021, no. 1 (2021):34-40,
https://doi.org/10.5937/zasmat2101034M . .

TY  - JOUR
AU  - Bajić, Darko
AU  - Mrdak, Mihailo
AU  - Bajić, Nikola
AU  - Veljić, Darko
AU  - Rakin, Marko
AU  - Radosavljević, Zoran
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4534
AB  - In this paper, we will present our investigation of the quality of J55 microalloyed steel welds that were formed by a basic flux-cored wire electrodes that were of appropriate quality and alloyed with Ni and Mo. Based on the comparison and analysis of the obtained results related to the testing of the chemical composition, mechanical properties, toughness at test temperatures, and the microstructure of welding joints formed by a classic and specially coated rutile flux-cored electrode, we assessed the justification to switch from solid wire electrodes to flux-cored alloyed wire electrodes of appropriate quality. The research aim for the application of flux-cored wire electrodes instead of solid wire electrodes is based on the advantages pertaining to a flux-cored wire: molten metal from electrode wire is transferred in the form of fine droplets, easy welding and maximum productivity within all spatial positions related to welding, improved properties of welding joints, and increased productivity when compared to a classic solid wire. Our research encompasses the development of the experimental production at the Research and Development Center IHIS Belgrade (Development Institute for Chemical Power Sources), Serbia, of the new type of a coated electrode with improved welding properties when compared to a classic electrode intended for microalloyed steel welding.
PB  - MDPI, Basel
T2  - Materials
T1  - Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding
IS  - 9
VL  - 13
DO  - 10.3390/ma13092152
ER  - 

@article{
author = "Bajić, Darko and Mrdak, Mihailo and Bajić, Nikola and Veljić, Darko and Rakin, Marko and Radosavljević, Zoran",
year = "2020",
abstract = "In this paper, we will present our investigation of the quality of J55 microalloyed steel welds that were formed by a basic flux-cored wire electrodes that were of appropriate quality and alloyed with Ni and Mo. Based on the comparison and analysis of the obtained results related to the testing of the chemical composition, mechanical properties, toughness at test temperatures, and the microstructure of welding joints formed by a classic and specially coated rutile flux-cored electrode, we assessed the justification to switch from solid wire electrodes to flux-cored alloyed wire electrodes of appropriate quality. The research aim for the application of flux-cored wire electrodes instead of solid wire electrodes is based on the advantages pertaining to a flux-cored wire: molten metal from electrode wire is transferred in the form of fine droplets, easy welding and maximum productivity within all spatial positions related to welding, improved properties of welding joints, and increased productivity when compared to a classic solid wire. Our research encompasses the development of the experimental production at the Research and Development Center IHIS Belgrade (Development Institute for Chemical Power Sources), Serbia, of the new type of a coated electrode with improved welding properties when compared to a classic electrode intended for microalloyed steel welding.",
publisher = "MDPI, Basel",
journal = "Materials",
title = "Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding",
number = "9",
volume = "13",
doi = "10.3390/ma13092152"
}

Bajić, D., Mrdak, M., Bajić, N., Veljić, D., Rakin, M.,& Radosavljević, Z.. (2020). Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding. in Materials
MDPI, Basel., 13(9).
https://doi.org/10.3390/ma13092152

Bajić D, Mrdak M, Bajić N, Veljić D, Rakin M, Radosavljević Z. Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding. in Materials. 2020;13(9).
doi:10.3390/ma13092152 .

Bajić, Darko, Mrdak, Mihailo, Bajić, Nikola, Veljić, Darko, Rakin, Marko, Radosavljević, Zoran, "Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding" in Materials, 13, no. 9 (2020),
https://doi.org/10.3390/ma13092152 . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Janaćković, Đorđe
AU  - Veljić, Darko
AU  - Bajić, Darko
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4552
AB  - The topography of the surface of the deposited VPS-Ti coatings on substrate surfaces of implants relating to the roughness and porous structure plays a decisive role in the process of on growth of the implants to the bones i.e.osseointegration. Direct bone on growth has been successfully achieved by using micro rough coating surfaces, such as the use of vacuum plasma spraying VPS-Ti coatings. The aim of this study was to make a comprehensive review of the characterization of porous VPS-Ti coatings deposited on substrates of titanium alloy that will find application in orthopedics.One of the preferred features of the VPS process is the ability to achieve optimum macro and micro structure of the surface of implants by optimizing the spray parameters of the powder deposition and by the range of the powder granulation. In order to achieve an optimum surface roughness, open porosity and structure of VPS-Ti coatings conducted was the optimization of deposition of powder with a change in plasma current and powder carrier gas flow rate of (700 A, 35 l/min and 800A, 20 l/min). Lower intensity plasma current with a greater flow of powder heats and melts the powder particles less forming micro pores of a larger size and a higher proportion of open pores and vice versa higher plasma currents and reduced flow provide better melted particles forming a smaller share of micro pores and open porosity in the deposited layers. Image analysis showed that by optimization of parameters in the coatings open porosity can be formed ranging from 45% to 57%. By examining the properties of the deposited layers it was determined that the most optimal roughness and share of open pores for osseointegration have the Ti layers which have been deposited with the lowest amperage and highest flow of powder carrier gas.
AB  - Topografija površine deponovanih VPS-Ti prevlaka na podlogama implanata koja se odnosi na hrapavost i poroznu strukturu imaju odlučujuću ulogu u procesu srastanja implanata sa kostima odnosno osteointegraciju Direktno urastanje kostiju uspešno se posti e korišćenjem mikro grubih površina prevlaka, kao što je primena vakuum plazma sprej VPS - Ti prevlake. Cilj ovog rada je bio da se napravi sveobuhvatan pregled karakterizacija VPS-Ti poroznih prevlaka deponovanih na podlogama od legure titana koje će naći aplikaciju u ortopediji. Jedna od povoljnih osobina VPS procesa je mogućnost postizanja optimalne makro i mikro strukture površine implanata optimizacijom sprej parametara depozicije praha i rasponom granulacije praha. U cilju postizanja optimalne hrapavosti, otvorene poroznosti i strukture VPS-Ti prevlaka sprovedena je optimizacija depozicije praha sa promenom plazma struje i protokom nosećeg gasa praha (700 A, 35 l/min i 800A, 20 l/min) Ni a jačina plazma struje uz veći protok praha slabije progreva i topi čestice praha obrazujući mikro pore veće veličine i veći udeo otvorenih pora i obrnuto veća plazma struja i manji protok omogućuju bolje topljenje čestica uz formiranje manjeg udela mikro pora i otvorene poroznosti u deponovanim slojevima. Analizom slika ustanovljeno je da se sa optimizacijom parametara u prevlakama mo e formirati otvorena poroznost sa rasponom od 45% do 57% Ispitivanjem karakteristika deponovanih slojeva ustanovljeno je da najoptimalniju hrapavost i udeo otvorenih pora za osteointegraciju imaju slojevi Ti deponovani sa najni om ampera om i najvećim protokom nosećeg gasa praha.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - The mechanical and microstructural properties of VPS-Ti porous coating deposited on titanium alloy substrates for osseointegration
T1  - Mehanička i mikrostrukturna svojstva VPS-Ti porozne prevlake deponovane na podlogama od legure titana za osteointegraciju
EP  - 59
IS  - 1
SP  - 52
VL  - 61
DO  - 10.5937/zasmat2001052M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Janaćković, Đorđe and Veljić, Darko and Bajić, Darko",
year = "2020",
abstract = "The topography of the surface of the deposited VPS-Ti coatings on substrate surfaces of implants relating to the roughness and porous structure plays a decisive role in the process of on growth of the implants to the bones i.e.osseointegration. Direct bone on growth has been successfully achieved by using micro rough coating surfaces, such as the use of vacuum plasma spraying VPS-Ti coatings. The aim of this study was to make a comprehensive review of the characterization of porous VPS-Ti coatings deposited on substrates of titanium alloy that will find application in orthopedics.One of the preferred features of the VPS process is the ability to achieve optimum macro and micro structure of the surface of implants by optimizing the spray parameters of the powder deposition and by the range of the powder granulation. In order to achieve an optimum surface roughness, open porosity and structure of VPS-Ti coatings conducted was the optimization of deposition of powder with a change in plasma current and powder carrier gas flow rate of (700 A, 35 l/min and 800A, 20 l/min). Lower intensity plasma current with a greater flow of powder heats and melts the powder particles less forming micro pores of a larger size and a higher proportion of open pores and vice versa higher plasma currents and reduced flow provide better melted particles forming a smaller share of micro pores and open porosity in the deposited layers. Image analysis showed that by optimization of parameters in the coatings open porosity can be formed ranging from 45% to 57%. By examining the properties of the deposited layers it was determined that the most optimal roughness and share of open pores for osseointegration have the Ti layers which have been deposited with the lowest amperage and highest flow of powder carrier gas., Topografija površine deponovanih VPS-Ti prevlaka na podlogama implanata koja se odnosi na hrapavost i poroznu strukturu imaju odlučujuću ulogu u procesu srastanja implanata sa kostima odnosno osteointegraciju Direktno urastanje kostiju uspešno se posti e korišćenjem mikro grubih površina prevlaka, kao što je primena vakuum plazma sprej VPS - Ti prevlake. Cilj ovog rada je bio da se napravi sveobuhvatan pregled karakterizacija VPS-Ti poroznih prevlaka deponovanih na podlogama od legure titana koje će naći aplikaciju u ortopediji. Jedna od povoljnih osobina VPS procesa je mogućnost postizanja optimalne makro i mikro strukture površine implanata optimizacijom sprej parametara depozicije praha i rasponom granulacije praha. U cilju postizanja optimalne hrapavosti, otvorene poroznosti i strukture VPS-Ti prevlaka sprovedena je optimizacija depozicije praha sa promenom plazma struje i protokom nosećeg gasa praha (700 A, 35 l/min i 800A, 20 l/min) Ni a jačina plazma struje uz veći protok praha slabije progreva i topi čestice praha obrazujući mikro pore veće veličine i veći udeo otvorenih pora i obrnuto veća plazma struja i manji protok omogućuju bolje topljenje čestica uz formiranje manjeg udela mikro pora i otvorene poroznosti u deponovanim slojevima. Analizom slika ustanovljeno je da se sa optimizacijom parametara u prevlakama mo e formirati otvorena poroznost sa rasponom od 45% do 57% Ispitivanjem karakteristika deponovanih slojeva ustanovljeno je da najoptimalniju hrapavost i udeo otvorenih pora za osteointegraciju imaju slojevi Ti deponovani sa najni om ampera om i najvećim protokom nosećeg gasa praha.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "The mechanical and microstructural properties of VPS-Ti porous coating deposited on titanium alloy substrates for osseointegration, Mehanička i mikrostrukturna svojstva VPS-Ti porozne prevlake deponovane na podlogama od legure titana za osteointegraciju",
pages = "59-52",
number = "1",
volume = "61",
doi = "10.5937/zasmat2001052M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Janaćković, Đ., Veljić, D.,& Bajić, D.. (2020). The mechanical and microstructural properties of VPS-Ti porous coating deposited on titanium alloy substrates for osseointegration. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 61(1), 52-59.
https://doi.org/10.5937/zasmat2001052M

Mrdak M, Lačnjevac Č, Rakin M, Janaćković Đ, Veljić D, Bajić D. The mechanical and microstructural properties of VPS-Ti porous coating deposited on titanium alloy substrates for osseointegration. in Zaštita materijala. 2020;61(1):52-59.
doi:10.5937/zasmat2001052M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Janaćković, Đorđe, Veljić, Darko, Bajić, Darko, "The mechanical and microstructural properties of VPS-Ti porous coating deposited on titanium alloy substrates for osseointegration" in Zaštita materijala, 61, no. 1 (2020):52-59,
https://doi.org/10.5937/zasmat2001052M . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Rakin, Marko
AU  - Janaćković, Đorđe
AU  - Veljić, Darko
AU  - Bajić, Darko
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4555
AB  - In this paper analyzed were the mechanical properties and microstructure of the Ni30Al coating layers deposited using atmospheric plasma spray (APS). For deposition of the coating applied was a composite Ni30wt.% Al powder, manufactured by mechanical alloying of granulation below - 180 µm. The coatings mechanical properties were analyzed by microhardness measuring with the HV0.3 method and the bond strength by tension method. For the analysis of the microstructure of the coating layers applied was the method of light and scanning electron microscopy (SEM). Microhardness tests showed that the coating has a wide range of measured values which indicate a heterogeneous multiphase lamellar microstructure of the coating, which was confirmed by metallographic examination of the layers. The multi-phase lamellar microstructure consisted of the initial solid a-Al, y-Ni solutions, formed solid b-NiAl and NiAl martensite solutions, intermetallic compounds y-Ni3Al and Ni2Al3 and the oxide y-Al2O3 phase formed by oxidation of molten Al particles. Based on these tests given was an evaluation of the quality of the coating. The results of the experiment showed that the technological process of production of composite powders significantly affects the mechanical properties and structure of the coating layers.
AB  - U ovom radu analizirane su mehaničke osobine i mikrostruktura slojeva prevlake Ni30Al deponovane atmosferskim plazma sprejom (APS). Za depoziciju prevlake primenjen je kompozitni prah Ni30tež.%Al proizveden mehaničkim legiranjem granulacije ispod - 180 µm. Mehaničke karakteristike prevlake analizirane su merenjem mikrotvrdoće metodom HV0.3 i čvrstoće spoja metodom na zatezanje. Za analizu mikrostrukture slojeva prevlake primenjena je metoda svetlosne i skening elektronske mikroskopije (SEM). Ispitivanja mikrotvrdoće su pokazala da prevlaka ima širok opseg izmerenih vrednosti koje ukazuju na višefaznu heterogenu lamelarnu mikrostrukturu prevlake, koja je potvrđena metalografskaim ispitivanjem slojeva. Višefazna lamelarna mikrostruktura se sastojala od polaznih čvrstih rastvora a-Al, y-Ni, formiranih čvrstih rastvora b-NiAl i NiAl martenzita, intermetalnih jedinjenja y-Ni3Al i Ni2Al3 i oksidne faze y-Al2O3 nastale oksidacijim istopljenih čestica Al. Na osnovu sprovedenih ispitivanja dala se ocena kvaliteta prevlake. Rezultati eksperimenta su pokazali da tehnološki postupak proizvodnje kompozitnih prahova bitno utiče na mehaničke karakteristike i strukturu slojeva prevlake.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Characterization of NiAl layers deposited by atmospheric plasma spray (APS)
T1  - Karakterizacija NiAl slojeva deponovanih atmosferskim plazma sprejom (APS)
EP  - 115
IS  - 2
SP  - 110
VL  - 61
DO  - 10.5937/zasmat2002110M
ER  - 

@article{
author = "Mrdak, Mihailo and Rakin, Marko and Janaćković, Đorđe and Veljić, Darko and Bajić, Darko",
year = "2020",
abstract = "In this paper analyzed were the mechanical properties and microstructure of the Ni30Al coating layers deposited using atmospheric plasma spray (APS). For deposition of the coating applied was a composite Ni30wt.% Al powder, manufactured by mechanical alloying of granulation below - 180 µm. The coatings mechanical properties were analyzed by microhardness measuring with the HV0.3 method and the bond strength by tension method. For the analysis of the microstructure of the coating layers applied was the method of light and scanning electron microscopy (SEM). Microhardness tests showed that the coating has a wide range of measured values which indicate a heterogeneous multiphase lamellar microstructure of the coating, which was confirmed by metallographic examination of the layers. The multi-phase lamellar microstructure consisted of the initial solid a-Al, y-Ni solutions, formed solid b-NiAl and NiAl martensite solutions, intermetallic compounds y-Ni3Al and Ni2Al3 and the oxide y-Al2O3 phase formed by oxidation of molten Al particles. Based on these tests given was an evaluation of the quality of the coating. The results of the experiment showed that the technological process of production of composite powders significantly affects the mechanical properties and structure of the coating layers., U ovom radu analizirane su mehaničke osobine i mikrostruktura slojeva prevlake Ni30Al deponovane atmosferskim plazma sprejom (APS). Za depoziciju prevlake primenjen je kompozitni prah Ni30tež.%Al proizveden mehaničkim legiranjem granulacije ispod - 180 µm. Mehaničke karakteristike prevlake analizirane su merenjem mikrotvrdoće metodom HV0.3 i čvrstoće spoja metodom na zatezanje. Za analizu mikrostrukture slojeva prevlake primenjena je metoda svetlosne i skening elektronske mikroskopije (SEM). Ispitivanja mikrotvrdoće su pokazala da prevlaka ima širok opseg izmerenih vrednosti koje ukazuju na višefaznu heterogenu lamelarnu mikrostrukturu prevlake, koja je potvrđena metalografskaim ispitivanjem slojeva. Višefazna lamelarna mikrostruktura se sastojala od polaznih čvrstih rastvora a-Al, y-Ni, formiranih čvrstih rastvora b-NiAl i NiAl martenzita, intermetalnih jedinjenja y-Ni3Al i Ni2Al3 i oksidne faze y-Al2O3 nastale oksidacijim istopljenih čestica Al. Na osnovu sprovedenih ispitivanja dala se ocena kvaliteta prevlake. Rezultati eksperimenta su pokazali da tehnološki postupak proizvodnje kompozitnih prahova bitno utiče na mehaničke karakteristike i strukturu slojeva prevlake.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Characterization of NiAl layers deposited by atmospheric plasma spray (APS), Karakterizacija NiAl slojeva deponovanih atmosferskim plazma sprejom (APS)",
pages = "115-110",
number = "2",
volume = "61",
doi = "10.5937/zasmat2002110M"
}

Mrdak, M., Rakin, M., Janaćković, Đ., Veljić, D.,& Bajić, D.. (2020). Characterization of NiAl layers deposited by atmospheric plasma spray (APS). in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 61(2), 110-115.
https://doi.org/10.5937/zasmat2002110M

Mrdak M, Rakin M, Janaćković Đ, Veljić D, Bajić D. Characterization of NiAl layers deposited by atmospheric plasma spray (APS). in Zaštita materijala. 2020;61(2):110-115.
doi:10.5937/zasmat2002110M .

Mrdak, Mihailo, Rakin, Marko, Janaćković, Đorđe, Veljić, Darko, Bajić, Darko, "Characterization of NiAl layers deposited by atmospheric plasma spray (APS)" in Zaštita materijala, 61, no. 2 (2020):110-115,
https://doi.org/10.5937/zasmat2002110M . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Bajic, Darko
AU  - Veljić, Darko
AU  - Rakin, Marko
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4750
AB  - Titanium dioxide (TiO2) is a multifunctional oxide that is an interesting material for many technological applications. This paper presents the mechanical properties and microstructure of TiO2 coatings resistant to dry sliding friction, corrosion, grain abrasion and erosion of particles at operating temperatures up to 540 degrees C. Layers of TiO2 coatings have been successfully deposited on test samples of steel C.4171 (X15Cr13 EN10027) using the atmospheric plasma spray (APS) process with plasma gun distances of 100 mm and 110 mm from the substrate. The APS procedure is used to produce relatively thick coatings of biocompatible and antibacterial TiO2 ceramic coatings for orthopedic applications. The coatings were deposited using the Plasmadyne company plasma spray system and Metco TiO2 powder, whose particles have an angular morphology produced by the melting and grinding cast blocks. The evaluation of the mechanical properties of the layers was made using the microhardness testing method HV0.3 and the tensile bond strength by tension testing. The analysis of the microstructure of the sprayed TiO2 coating layers was made in accordance with the Pratt & Whitney standard, using optical microscopy (OM). The morphology of the powder particles, the surface of the deposited coating and the coating fractures were examined by scanning electron microscopy. Tests have shown that the layers of TiO2 coatings deposited with a plasma spray distance of 110 mm have good mechanical properties and microstructure, which allow its use in the development of biomedical implants.
T2  - Materiali in Tehnologije
T1  - Mechanical and structural characteristics of atmospheric plasma-sprayed multifunctional tio2 coatings
EP  - 812
IS  - 6
SP  - 807
VL  - 54
DO  - 10.17222/mit.2020.052
ER  - 

@article{
author = "Mrdak, Mihailo and Bajic, Darko and Veljić, Darko and Rakin, Marko",
year = "2020",
abstract = "Titanium dioxide (TiO2) is a multifunctional oxide that is an interesting material for many technological applications. This paper presents the mechanical properties and microstructure of TiO2 coatings resistant to dry sliding friction, corrosion, grain abrasion and erosion of particles at operating temperatures up to 540 degrees C. Layers of TiO2 coatings have been successfully deposited on test samples of steel C.4171 (X15Cr13 EN10027) using the atmospheric plasma spray (APS) process with plasma gun distances of 100 mm and 110 mm from the substrate. The APS procedure is used to produce relatively thick coatings of biocompatible and antibacterial TiO2 ceramic coatings for orthopedic applications. The coatings were deposited using the Plasmadyne company plasma spray system and Metco TiO2 powder, whose particles have an angular morphology produced by the melting and grinding cast blocks. The evaluation of the mechanical properties of the layers was made using the microhardness testing method HV0.3 and the tensile bond strength by tension testing. The analysis of the microstructure of the sprayed TiO2 coating layers was made in accordance with the Pratt & Whitney standard, using optical microscopy (OM). The morphology of the powder particles, the surface of the deposited coating and the coating fractures were examined by scanning electron microscopy. Tests have shown that the layers of TiO2 coatings deposited with a plasma spray distance of 110 mm have good mechanical properties and microstructure, which allow its use in the development of biomedical implants.",
journal = "Materiali in Tehnologije",
title = "Mechanical and structural characteristics of atmospheric plasma-sprayed multifunctional tio2 coatings",
pages = "812-807",
number = "6",
volume = "54",
doi = "10.17222/mit.2020.052"
}

Mrdak, M., Bajic, D., Veljić, D.,& Rakin, M.. (2020). Mechanical and structural characteristics of atmospheric plasma-sprayed multifunctional tio2 coatings. in Materiali in Tehnologije, 54(6), 807-812.
https://doi.org/10.17222/mit.2020.052

Mrdak M, Bajic D, Veljić D, Rakin M. Mechanical and structural characteristics of atmospheric plasma-sprayed multifunctional tio2 coatings. in Materiali in Tehnologije. 2020;54(6):807-812.
doi:10.17222/mit.2020.052 .

Mrdak, Mihailo, Bajic, Darko, Veljić, Darko, Rakin, Marko, "Mechanical and structural characteristics of atmospheric plasma-sprayed multifunctional tio2 coatings" in Materiali in Tehnologije, 54, no. 6 (2020):807-812,
https://doi.org/10.17222/mit.2020.052 . .

TY  - CONF
AU  - Mrdak, Mihailo
AU  - Pekez, Jasmina
AU  - Bajić, Nikola
AU  - Rakin, Marko
AU  - Veljić, Darko
AU  - Radosavljević, Zoran
AU  - Đurđev, Mića
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6338
PB  - Central and Eastern European Committee of Thermal Analysis and Calorimetry
C3  - 5th Central and Eastern European Conference on Thermal Analysis and Calorimetry & 14th Mediterranean Conference on Calorimetry and Thermal Analysis
T1  - Characterization of weld metal in welded microalloyed steel J55 made using a rutile electrode with a flux-cored wire core
SP  - 466
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6338
ER  - 

@conference{
author = "Mrdak, Mihailo and Pekez, Jasmina and Bajić, Nikola and Rakin, Marko and Veljić, Darko and Radosavljević, Zoran and Đurđev, Mića",
year = "2019",
publisher = "Central and Eastern European Committee of Thermal Analysis and Calorimetry",
journal = "5th Central and Eastern European Conference on Thermal Analysis and Calorimetry & 14th Mediterranean Conference on Calorimetry and Thermal Analysis",
title = "Characterization of weld metal in welded microalloyed steel J55 made using a rutile electrode with a flux-cored wire core",
pages = "466",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6338"
}

Mrdak, M., Pekez, J., Bajić, N., Rakin, M., Veljić, D., Radosavljević, Z.,& Đurđev, M.. (2019). Characterization of weld metal in welded microalloyed steel J55 made using a rutile electrode with a flux-cored wire core. in 5th Central and Eastern European Conference on Thermal Analysis and Calorimetry & 14th Mediterranean Conference on Calorimetry and Thermal Analysis
Central and Eastern European Committee of Thermal Analysis and Calorimetry., 466.
https://hdl.handle.net/21.15107/rcub_technorep_6338

Mrdak M, Pekez J, Bajić N, Rakin M, Veljić D, Radosavljević Z, Đurđev M. Characterization of weld metal in welded microalloyed steel J55 made using a rutile electrode with a flux-cored wire core. in 5th Central and Eastern European Conference on Thermal Analysis and Calorimetry & 14th Mediterranean Conference on Calorimetry and Thermal Analysis. 2019;:466.
https://hdl.handle.net/21.15107/rcub_technorep_6338 .

Mrdak, Mihailo, Pekez, Jasmina, Bajić, Nikola, Rakin, Marko, Veljić, Darko, Radosavljević, Zoran, Đurđev, Mića, "Characterization of weld metal in welded microalloyed steel J55 made using a rutile electrode with a flux-cored wire core" in 5th Central and Eastern European Conference on Thermal Analysis and Calorimetry & 14th Mediterranean Conference on Calorimetry and Thermal Analysis (2019):466,
https://hdl.handle.net/21.15107/rcub_technorep_6338 .

TY  - JOUR
AU  - Veljić, Darko
AU  - Rakin, Marko
AU  - Međo, Bojan
AU  - Mrdak, Mihailo
AU  - Sedmak, Aleksandar
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4107
AB  - Friction stir welding is one of the procedures for joining the parts in solid state. Thermo-mechanical simulation of the friction stir welding of high-strength aluminium alloys 2024 T3 and 2024 T351 is considered in this work. Numerical models corresponding to the linear welding stage are developed in Abaqus software package. The material behaviour is modelled by Johnson-Cook law (which relates the yield stress with temperature, strain and strain rate), and the Arbitrary Lagrangian-Eulerian technique is applied. The difference in thermo-mechanical behaviour between the two materials has been analysed and commented. The main quantities which are considered are the temperature in the weld area, plastic strain, as well as the rate of heat generation during the welding process.
PB  - Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd
T2  - Thermal Science
T1  - Temperature fields in linear stage of friction stir welding effect of different material properties
EP  - 3992
IS  - 6
SP  - 3985
VL  - 23
DO  - 10.2298/TSCI181015264V
ER  - 

@article{
author = "Veljić, Darko and Rakin, Marko and Međo, Bojan and Mrdak, Mihailo and Sedmak, Aleksandar",
year = "2019",
abstract = "Friction stir welding is one of the procedures for joining the parts in solid state. Thermo-mechanical simulation of the friction stir welding of high-strength aluminium alloys 2024 T3 and 2024 T351 is considered in this work. Numerical models corresponding to the linear welding stage are developed in Abaqus software package. The material behaviour is modelled by Johnson-Cook law (which relates the yield stress with temperature, strain and strain rate), and the Arbitrary Lagrangian-Eulerian technique is applied. The difference in thermo-mechanical behaviour between the two materials has been analysed and commented. The main quantities which are considered are the temperature in the weld area, plastic strain, as well as the rate of heat generation during the welding process.",
publisher = "Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd",
journal = "Thermal Science",
title = "Temperature fields in linear stage of friction stir welding effect of different material properties",
pages = "3992-3985",
number = "6",
volume = "23",
doi = "10.2298/TSCI181015264V"
}

Veljić, D., Rakin, M., Međo, B., Mrdak, M.,& Sedmak, A.. (2019). Temperature fields in linear stage of friction stir welding effect of different material properties. in Thermal Science
Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd., 23(6), 3985-3992.
https://doi.org/10.2298/TSCI181015264V

Veljić D, Rakin M, Međo B, Mrdak M, Sedmak A. Temperature fields in linear stage of friction stir welding effect of different material properties. in Thermal Science. 2019;23(6):3985-3992.
doi:10.2298/TSCI181015264V .

Veljić, Darko, Rakin, Marko, Međo, Bojan, Mrdak, Mihailo, Sedmak, Aleksandar, "Temperature fields in linear stage of friction stir welding effect of different material properties" in Thermal Science, 23, no. 6 (2019):3985-3992,
https://doi.org/10.2298/TSCI181015264V . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Međo, Bojan
AU  - Veljić, Darko
AU  - Arsić, Miodrag
AU  - Rakin, Marko
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4237
AB  - In this paper, structural and mechanical properties of APS - atmospheric plasma spray coating Al-12Si are presented. The aim of the research was the optimisation of the flow of powder to produce layers with optimal mechanical and structural properties that will be applied to the worn out parts of airplanes. Three groups of samples were produced, by utilising three powder feed rates: 30 g/min, 45 g/min and 60 g/min. Evaluation of layers' microhardness was done using HV0.3 method and the bond strength was determined by testing of tensile strength. Surface morphology of the deposited powder particles was examined on SEM (Scanning Electron Microscope). The microstructure of the coating with the best measured mechanical properties was subsequently examined in etched condition on optical microscope and SEM (in accordance with the standard PN 585005, Pratt & Whitney). Also, fracture morphology of this coating in deposited state was examined using SEM. It was found that powder feed control with atmospheric plasma spraying can produce dense layers of Al-12Si coating with good bond strength.
PB  - Walter de Gruyter Gmbh, Berlin
T2  - Reviews on Advanced Materials Science
T1  - The influence of powder feed rate on mechanical properties of atmospheric plasma spray (APS) Al-12Si coating
EP  - 81
IS  - 1
SP  - 75
VL  - 58
DO  - 10.1515/rams-2019-0007
ER  - 

@article{
author = "Mrdak, Mihailo and Međo, Bojan and Veljić, Darko and Arsić, Miodrag and Rakin, Marko",
year = "2019",
abstract = "In this paper, structural and mechanical properties of APS - atmospheric plasma spray coating Al-12Si are presented. The aim of the research was the optimisation of the flow of powder to produce layers with optimal mechanical and structural properties that will be applied to the worn out parts of airplanes. Three groups of samples were produced, by utilising three powder feed rates: 30 g/min, 45 g/min and 60 g/min. Evaluation of layers' microhardness was done using HV0.3 method and the bond strength was determined by testing of tensile strength. Surface morphology of the deposited powder particles was examined on SEM (Scanning Electron Microscope). The microstructure of the coating with the best measured mechanical properties was subsequently examined in etched condition on optical microscope and SEM (in accordance with the standard PN 585005, Pratt & Whitney). Also, fracture morphology of this coating in deposited state was examined using SEM. It was found that powder feed control with atmospheric plasma spraying can produce dense layers of Al-12Si coating with good bond strength.",
publisher = "Walter de Gruyter Gmbh, Berlin",
journal = "Reviews on Advanced Materials Science",
title = "The influence of powder feed rate on mechanical properties of atmospheric plasma spray (APS) Al-12Si coating",
pages = "81-75",
number = "1",
volume = "58",
doi = "10.1515/rams-2019-0007"
}

Mrdak, M., Međo, B., Veljić, D., Arsić, M.,& Rakin, M.. (2019). The influence of powder feed rate on mechanical properties of atmospheric plasma spray (APS) Al-12Si coating. in Reviews on Advanced Materials Science
Walter de Gruyter Gmbh, Berlin., 58(1), 75-81.
https://doi.org/10.1515/rams-2019-0007

Mrdak M, Međo B, Veljić D, Arsić M, Rakin M. The influence of powder feed rate on mechanical properties of atmospheric plasma spray (APS) Al-12Si coating. in Reviews on Advanced Materials Science. 2019;58(1):75-81.
doi:10.1515/rams-2019-0007 .

Mrdak, Mihailo, Međo, Bojan, Veljić, Darko, Arsić, Miodrag, Rakin, Marko, "The influence of powder feed rate on mechanical properties of atmospheric plasma spray (APS) Al-12Si coating" in Reviews on Advanced Materials Science, 58, no. 1 (2019):75-81,
https://doi.org/10.1515/rams-2019-0007 . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Veljić, Darko
AU  - Bajić, Nikola
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4273
AB  - Protective vacuum plasma spray VPS - NiCoCrAlY coating is used on sections of gas turbines to allow for longer and more reliable operation of sections exposed to aggressive effects of high temperature oxidation. Depositing of NiCoCrAlY alloy powder was done with the vacuum plasma spray system of the Plasma Technik - AG Companyon the A-2000 control unit using the plasma F4 gun. To test the mechanical properties and microstructure of the NiCoCrAlY coating, the powder was deposited on Č.4171 (X15Cr13 EN10027) steel substrates.To examine the microstructure of the coating in the heat-treated state, the powder was deposited on an IN738LC alloy substrate, which was pre-heated to a temperature of 750 to 800°C before deposition of the powder. The coating with the IN738LC alloy substrate was heat-treated at 1150°C for 2 hours in anargon shielded atmosphere. Mechanical testing of the microhardness of the coating was done using the HV0.3 method and the tensile bond strength using the tension method. The morphology of the powder particles and the morphology of the surface of the deposited coating were examined using a scanning electron microscope (SEM). The microstructure of coating layers in deposited state was tested on an optical microscope (OM). After thermal treatment, etching of the coating was done in the reagent CuSO4 + HCl aqueous solution. Analysis of the microstructure of the coating after etching was performed on the SEM, on the basis of which a score of the quality of the diffusion VPS - NiCoCrAlY coating was given.
AB  - Zaštitna vakuum plazma sprej VPS - NiCoCrAlY prevlaka se koriste na sekcijama gasnih turbina da bi se omogućio duži i pouzdaniji rad sekcijama izloženim agresivnom napadu visokotemperaturne oksidacije. Deponovanje praha od legure NiCoCrAlY urađeno je vakuum plazma sprej sistemom firme Plasma Technik - AG na upravljačkoj jedinici A-2000 sa plazma pištoljem F4. Za ispitivanje mehaničkih karakteristika i mikrostrukture NiCoCrAlY prevlake, prah je deponovan na substratima od čelika Č.4171 (X15Cr13 EN10027). Za ispitivanje mikrostrukture prevlake u termički obrađenom stanju, prah je deponovan na substratu od legure IN738LC, koji je pre depozicije praha bio predgrejan na temperaturi od 750 do 800°C. Prevlaka je sa substratom od legure IN738LC termički tretirana na 1150°C u trajanju od 2 sata u zaštitnoj atmosferi argona. Mehanička ispitivanja mikrotvrdoće prevlake urađena su metodom HV0.3 i zatezna čvrstoća spoja metodom na zatezanje. Morfologija čestica praha i morfologija površine deponovane prevlake ispitana je na skening elektronskom mikroskopu (SEM). Mikrostruktura slojeva prevlake u deponovanom stanju ispitana je na optičkom mikroskopu (OM). Posle termičke obrade sprovedeno je nagrizanje prevlake u reagensu CuSO4 + HCl vodeni rastvor. Analiza mikrostrukture prevlake posle nagrizanja urađena je na SEM-u, na osnovu čega se dala ocena kvaliteta difuzione VPS - NiCoCrAlY prevlake.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Characterization of vacuum plasma spray NiCoCrAlY coating resistant to high temperature oxidation
T1  - Karakterizacija vakuum plazma sprej prevlake NiCoCrAlY otporne na visokotemperaturnu oksidaciju
EP  - 341
IS  - 4
SP  - 336
VL  - 60
DO  - 10.5937/zasmat1904336M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Veljić, Darko and Bajić, Nikola",
year = "2019",
abstract = "Protective vacuum plasma spray VPS - NiCoCrAlY coating is used on sections of gas turbines to allow for longer and more reliable operation of sections exposed to aggressive effects of high temperature oxidation. Depositing of NiCoCrAlY alloy powder was done with the vacuum plasma spray system of the Plasma Technik - AG Companyon the A-2000 control unit using the plasma F4 gun. To test the mechanical properties and microstructure of the NiCoCrAlY coating, the powder was deposited on Č.4171 (X15Cr13 EN10027) steel substrates.To examine the microstructure of the coating in the heat-treated state, the powder was deposited on an IN738LC alloy substrate, which was pre-heated to a temperature of 750 to 800°C before deposition of the powder. The coating with the IN738LC alloy substrate was heat-treated at 1150°C for 2 hours in anargon shielded atmosphere. Mechanical testing of the microhardness of the coating was done using the HV0.3 method and the tensile bond strength using the tension method. The morphology of the powder particles and the morphology of the surface of the deposited coating were examined using a scanning electron microscope (SEM). The microstructure of coating layers in deposited state was tested on an optical microscope (OM). After thermal treatment, etching of the coating was done in the reagent CuSO4 + HCl aqueous solution. Analysis of the microstructure of the coating after etching was performed on the SEM, on the basis of which a score of the quality of the diffusion VPS - NiCoCrAlY coating was given., Zaštitna vakuum plazma sprej VPS - NiCoCrAlY prevlaka se koriste na sekcijama gasnih turbina da bi se omogućio duži i pouzdaniji rad sekcijama izloženim agresivnom napadu visokotemperaturne oksidacije. Deponovanje praha od legure NiCoCrAlY urađeno je vakuum plazma sprej sistemom firme Plasma Technik - AG na upravljačkoj jedinici A-2000 sa plazma pištoljem F4. Za ispitivanje mehaničkih karakteristika i mikrostrukture NiCoCrAlY prevlake, prah je deponovan na substratima od čelika Č.4171 (X15Cr13 EN10027). Za ispitivanje mikrostrukture prevlake u termički obrađenom stanju, prah je deponovan na substratu od legure IN738LC, koji je pre depozicije praha bio predgrejan na temperaturi od 750 do 800°C. Prevlaka je sa substratom od legure IN738LC termički tretirana na 1150°C u trajanju od 2 sata u zaštitnoj atmosferi argona. Mehanička ispitivanja mikrotvrdoće prevlake urađena su metodom HV0.3 i zatezna čvrstoća spoja metodom na zatezanje. Morfologija čestica praha i morfologija površine deponovane prevlake ispitana je na skening elektronskom mikroskopu (SEM). Mikrostruktura slojeva prevlake u deponovanom stanju ispitana je na optičkom mikroskopu (OM). Posle termičke obrade sprovedeno je nagrizanje prevlake u reagensu CuSO4 + HCl vodeni rastvor. Analiza mikrostrukture prevlake posle nagrizanja urađena je na SEM-u, na osnovu čega se dala ocena kvaliteta difuzione VPS - NiCoCrAlY prevlake.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Characterization of vacuum plasma spray NiCoCrAlY coating resistant to high temperature oxidation, Karakterizacija vakuum plazma sprej prevlake NiCoCrAlY otporne na visokotemperaturnu oksidaciju",
pages = "341-336",
number = "4",
volume = "60",
doi = "10.5937/zasmat1904336M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Veljić, D.,& Bajić, N.. (2019). Characterization of vacuum plasma spray NiCoCrAlY coating resistant to high temperature oxidation. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 60(4), 336-341.
https://doi.org/10.5937/zasmat1904336M

Mrdak M, Lačnjevac Č, Rakin M, Veljić D, Bajić N. Characterization of vacuum plasma spray NiCoCrAlY coating resistant to high temperature oxidation. in Zaštita materijala. 2019;60(4):336-341.
doi:10.5937/zasmat1904336M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Veljić, Darko, Bajić, Nikola, "Characterization of vacuum plasma spray NiCoCrAlY coating resistant to high temperature oxidation" in Zaštita materijala, 60, no. 4 (2019):336-341,
https://doi.org/10.5937/zasmat1904336M . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Bajić, Nikola
AU  - Veljić, Darko
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4275
AB  - This paper presents the results of testing mechanical and structural characteristics of plasma spray coating Al2O328wt.%MgO. Metal oxide MgO in a complex oxide Al2O328wt.%MgO modifies the properties of Al2O3 ceramics by forming spinel MgAl2O4 with excellent biomedical characteristics. The coating layers were deposited by atmospheric plasma spraying process (APS) on steel substrates of stainless steel X15Cr13 (EN 1.4024). The aim of this study was to examine the effect of the strength of the plasma current (700A, 800A and 900A) on the mechanical properties of the Al2O3MgO coating, pore content and microstructure of the layers. Testing microhardness of the layers using the HV0.3 method, the bond strength using the tensile method and microstructure using optical microscopy (OM) and scanning electron microscopy (SEM) have confirmed that, by controlling the plasma current, layers of the coating system Al2O328wt.%MgO can be deposited with good mechanical and microstructural characteristics suitable for use in manufacture of implants.
AB  - U ovom radu su prikazani rezultati ispitivanja mehaničkih i strukturnih karakteristika plazma sprej prevlake Al2O328tež.%MgO. Metalni oksid MgO u kompleksnom oksidu Al2O328tež.%MgO modifikuje osobine Al2O3 keramike formiranjem spinela MgAl2O4 odličnih biomedicinskih karakteristika. Slojevi prevlake su deponovani atmosferski plazma sprej procesom (APS) na čeličnim podlogama od nerđajućeg čelika X15Cr13 (EN 1.4024). Cilj ovog rada je bio da se ispita efekat jačine plazma struje (700A, 800A i 900A) na mehaničke osobine prevlake Al2O3MgO, sadržaj pora i mikrostrukturu slojeva. Ispitivanja mikrotvrdoće slojeva metodama HV0.3, čvrstoće spoja zatezanjem i mikrostrukture optičkom mikroskopijom (OM) i skening elektronskom mikroskopijom (SEM) su potvrdila da se sa kontrolom plazma struje mogu deponovati slojevi sistema prevlake Al2O328tež.%MgO dobrih mehaničkih i mikrostrukturih karakteristika pogodnih za primenu u eksploataciji za proizvodnju implanata.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Characterization of plasma spray bioinert coating Al2O328wt.%MgO
T1  - Karakterizacija plazma sprej bioinertne prevlake Al2O328tež.%MgO
EP  - 49
IS  - 1
SP  - 44
VL  - 60
DO  - 10.5937/zasmat1901044M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Bajić, Nikola and Veljić, Darko",
year = "2019",
abstract = "This paper presents the results of testing mechanical and structural characteristics of plasma spray coating Al2O328wt.%MgO. Metal oxide MgO in a complex oxide Al2O328wt.%MgO modifies the properties of Al2O3 ceramics by forming spinel MgAl2O4 with excellent biomedical characteristics. The coating layers were deposited by atmospheric plasma spraying process (APS) on steel substrates of stainless steel X15Cr13 (EN 1.4024). The aim of this study was to examine the effect of the strength of the plasma current (700A, 800A and 900A) on the mechanical properties of the Al2O3MgO coating, pore content and microstructure of the layers. Testing microhardness of the layers using the HV0.3 method, the bond strength using the tensile method and microstructure using optical microscopy (OM) and scanning electron microscopy (SEM) have confirmed that, by controlling the plasma current, layers of the coating system Al2O328wt.%MgO can be deposited with good mechanical and microstructural characteristics suitable for use in manufacture of implants., U ovom radu su prikazani rezultati ispitivanja mehaničkih i strukturnih karakteristika plazma sprej prevlake Al2O328tež.%MgO. Metalni oksid MgO u kompleksnom oksidu Al2O328tež.%MgO modifikuje osobine Al2O3 keramike formiranjem spinela MgAl2O4 odličnih biomedicinskih karakteristika. Slojevi prevlake su deponovani atmosferski plazma sprej procesom (APS) na čeličnim podlogama od nerđajućeg čelika X15Cr13 (EN 1.4024). Cilj ovog rada je bio da se ispita efekat jačine plazma struje (700A, 800A i 900A) na mehaničke osobine prevlake Al2O3MgO, sadržaj pora i mikrostrukturu slojeva. Ispitivanja mikrotvrdoće slojeva metodama HV0.3, čvrstoće spoja zatezanjem i mikrostrukture optičkom mikroskopijom (OM) i skening elektronskom mikroskopijom (SEM) su potvrdila da se sa kontrolom plazma struje mogu deponovati slojevi sistema prevlake Al2O328tež.%MgO dobrih mehaničkih i mikrostrukturih karakteristika pogodnih za primenu u eksploataciji za proizvodnju implanata.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Characterization of plasma spray bioinert coating Al2O328wt.%MgO, Karakterizacija plazma sprej bioinertne prevlake Al2O328tež.%MgO",
pages = "49-44",
number = "1",
volume = "60",
doi = "10.5937/zasmat1901044M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Bajić, N.,& Veljić, D.. (2019). Characterization of plasma spray bioinert coating Al2O328wt.%MgO. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 60(1), 44-49.
https://doi.org/10.5937/zasmat1901044M

Mrdak M, Lačnjevac Č, Rakin M, Bajić N, Veljić D. Characterization of plasma spray bioinert coating Al2O328wt.%MgO. in Zaštita materijala. 2019;60(1):44-49.
doi:10.5937/zasmat1901044M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Bajić, Nikola, Veljić, Darko, "Characterization of plasma spray bioinert coating Al2O328wt.%MgO" in Zaštita materijala, 60, no. 1 (2019):44-49,
https://doi.org/10.5937/zasmat1901044M . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Bajić, Nikola
AU  - Veljić, Darko
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4276
AB  - ZrO25CaO is a versatile class of material that can be sintered or plasma spray deposited in combination with other materials on the implant substrate. Due to brittleness the organic ceramic hydroxyapatite Ca10(PO4)6(OH)2 - (HA) is not suitable for use as a separate material in the process of making implants. In order to improve the mechanical characteristics and osteoconductivity, to HA ceramics added are dual systems of oxide solid solutions, of which one is also ZrO25CaO. Ceramics ZrO2-CaO(95%-5%) as a biomaterial facilitates osteoconductivity in new bone formation around the implant. This paper represents the need to develop a system of ZrO25CaO/NiCrAl coatings that will with their mechanical and structural characteristics find application on implant parts. In this context, using the atmospheric plasma spray process deposited were the ZrO25CaO/NiCrAl coatings system on stainless steel substrates X15Cr13 (EN 1.4024). Analysis of the morphology of the powder particles and the surface of the ZrO25CaO coatings was carried out on the SEM. The microstructure of the layers of the coatings system was analyzed on the OM. Mechanical properties of the coating were determined by examining the microhardness using the HV0.3 method and bond strength by tensile testing according to the standard (ASTMC633-1).
AB  - ZrO25CaO je višenamenska klasa materijala koja može da se sinteruje ili plazma sprej deponuje u kombinaciji sa drugim materijalima na podlogama implantata. Zbog krtosti organska keramika hidroksiapatit Ca10(PO4)6(OH)2 - (HA) nije pogodna za primenu kao zaseban materijal u procesu izrade implantata. U cilju poboljšanja osteokonduktivnosti i mehaničkih karakteristika, keramici HA se dodavaju dvojni sistemi čvrstih rastvora oksida od kojih je jedan i ZrO25CaO. Keramika ZrO2-CaO(95%-5%) kao biomaterijal olakšava osteokonduktivnost u novom formiranju kostiju oko implantata. Ovaj rad predstavlja potrebu za izradom sistema ZrO25CaO/NiCrAl prevlaka koje će po svojim mehaničkim i strukturnim karakteristikama naći primenu na delovima implantata. U tom kontekstu atmosferskim plazma sprej procesom deponovan je sistem prevlaka ZrO25CaO/NiCrAl na čeličnim podlogama od nerđajućeg čelika X15Cr13 (EN 1.4024). Analiza morfologije čestica praha i površine prevlaka ZrO25CaO sprovedena je na SEM-u. Mikrostruktura slojeva sistema prevlaka ispitana je na OM-u. Mehaničke karakteristike prevlaka su sprovedene ispitivanjem mikrotvrdoće metodom HV0.3 i čvrstoće spoja ispitivanjem na zatezanje po standardu (ASTMC633-1).
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Mechanical properties and microstructure of the ZrO25CaO/NiCrAl coating system
T1  - Mehaničke osobine i mikrostruktura sistema prevlaka ZrO25CaO/NiCrAl
EP  - 151
IS  - 2
SP  - 147
VL  - 60
DO  - 10.5937/zasmat1902147M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Bajić, Nikola and Veljić, Darko",
year = "2019",
abstract = "ZrO25CaO is a versatile class of material that can be sintered or plasma spray deposited in combination with other materials on the implant substrate. Due to brittleness the organic ceramic hydroxyapatite Ca10(PO4)6(OH)2 - (HA) is not suitable for use as a separate material in the process of making implants. In order to improve the mechanical characteristics and osteoconductivity, to HA ceramics added are dual systems of oxide solid solutions, of which one is also ZrO25CaO. Ceramics ZrO2-CaO(95%-5%) as a biomaterial facilitates osteoconductivity in new bone formation around the implant. This paper represents the need to develop a system of ZrO25CaO/NiCrAl coatings that will with their mechanical and structural characteristics find application on implant parts. In this context, using the atmospheric plasma spray process deposited were the ZrO25CaO/NiCrAl coatings system on stainless steel substrates X15Cr13 (EN 1.4024). Analysis of the morphology of the powder particles and the surface of the ZrO25CaO coatings was carried out on the SEM. The microstructure of the layers of the coatings system was analyzed on the OM. Mechanical properties of the coating were determined by examining the microhardness using the HV0.3 method and bond strength by tensile testing according to the standard (ASTMC633-1)., ZrO25CaO je višenamenska klasa materijala koja može da se sinteruje ili plazma sprej deponuje u kombinaciji sa drugim materijalima na podlogama implantata. Zbog krtosti organska keramika hidroksiapatit Ca10(PO4)6(OH)2 - (HA) nije pogodna za primenu kao zaseban materijal u procesu izrade implantata. U cilju poboljšanja osteokonduktivnosti i mehaničkih karakteristika, keramici HA se dodavaju dvojni sistemi čvrstih rastvora oksida od kojih je jedan i ZrO25CaO. Keramika ZrO2-CaO(95%-5%) kao biomaterijal olakšava osteokonduktivnost u novom formiranju kostiju oko implantata. Ovaj rad predstavlja potrebu za izradom sistema ZrO25CaO/NiCrAl prevlaka koje će po svojim mehaničkim i strukturnim karakteristikama naći primenu na delovima implantata. U tom kontekstu atmosferskim plazma sprej procesom deponovan je sistem prevlaka ZrO25CaO/NiCrAl na čeličnim podlogama od nerđajućeg čelika X15Cr13 (EN 1.4024). Analiza morfologije čestica praha i površine prevlaka ZrO25CaO sprovedena je na SEM-u. Mikrostruktura slojeva sistema prevlaka ispitana je na OM-u. Mehaničke karakteristike prevlaka su sprovedene ispitivanjem mikrotvrdoće metodom HV0.3 i čvrstoće spoja ispitivanjem na zatezanje po standardu (ASTMC633-1).",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Mechanical properties and microstructure of the ZrO25CaO/NiCrAl coating system, Mehaničke osobine i mikrostruktura sistema prevlaka ZrO25CaO/NiCrAl",
pages = "151-147",
number = "2",
volume = "60",
doi = "10.5937/zasmat1902147M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Bajić, N.,& Veljić, D.. (2019). Mechanical properties and microstructure of the ZrO25CaO/NiCrAl coating system. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 60(2), 147-151.
https://doi.org/10.5937/zasmat1902147M

Mrdak M, Lačnjevac Č, Rakin M, Bajić N, Veljić D. Mechanical properties and microstructure of the ZrO25CaO/NiCrAl coating system. in Zaštita materijala. 2019;60(2):147-151.
doi:10.5937/zasmat1902147M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Bajić, Nikola, Veljić, Darko, "Mechanical properties and microstructure of the ZrO25CaO/NiCrAl coating system" in Zaštita materijala, 60, no. 2 (2019):147-151,
https://doi.org/10.5937/zasmat1902147M . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Veljić, Darko
AU  - Bajić, Nikola
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4277
AB  - Molybdenum coatings due to their excellent wear resistant properties and sliding characteristics under dry friction conditions are often used in applications to resist friction and dry sliding. Since molybdenum metal is susceptible to oxidation, in this study, the molybdenum coating layers were successfully deposited at low pressure inert gas Ar using vacuum plasma spray technology (VPS). Characterization of the Mo coating was performed by measuring the microhardness of the coating layers using the Vickers HV0.3 method, the bond strength by tensile testing and the microstructure by optical microscopy (OM) and scanning electron microscopy (SEM). The microstructure of the coating layers was tested in deposited stateand after etching. The etching reagent used was NH3·H2O and H2O2 with a volume ratio of 1:2. The results showed that the coating has good mechanical properties, microhardness and high adhesion/cohesion strength. Layers of VPS - Mo coatings were composed of well-melted powder particles, partially unmelted particles with a good bond in the coating layers and micropores with a share below 0.5%. It was found that the microstructure of the coating consists mainly of lamellar structure and columnar crystal Mo grains. Tests have shown that the VPS - Mo coating layers have mechanical characteristics and a microstructure which fully enables the use of the coating on surfaces of parts which are required to have good sliding properties, resistance to wear and corrosion.
AB  - Prevlake molibdena se zbog svojih odličnih osobina na habanje i kliznih svojstva u uslovima suvog trenja često koriste u aplikacijama da se odupru trenju i suvom klizanju. Pošto je molibden metal osetljiv na oksidaciju, u ovoj studiji slojevi prevlake molibdena su uspešno deponovani na niskom pritisku inertnog gasa Ar vacuum plazma sprej tehnologijom (VPS). Karakterizacija prevlake Mo je izvršena merenjem mikrotvrdoće slojeva prevlake metodom Vickers HV0.3, čvrstoće spoja ispitivanjem na zatezanje i mikrostrukture metodom optičke mikroskopije (OM) i skening elektronske mikroskopije (SEM). Mikrostruktura slojeva prevlake je ispitana u deponovanom stanju i posle nagrizanja. Za nagrizanje se koristio reagens NH3·H2O i H2O2 sa zapreminskim odnosom 1:2. Dobijeni rezultati su pokazali da prevlaka ima dobre mehaničke karakteristike, mikrotvrdoću i visoku adheziono / kohezionu čvrstoću. Slojevi VPS - Mo prevlake su se sastojali od dobro istopljenih čestica praha, delimično neistopljenih čestica sa dobrom vezom u slojevima prevlake i mikro pora sa udelom ispod 0,5%. Utvrđeno je da se mikrostruktura prevlake uglavnom sastoji od lamelarne strukture i stubastih kristalnih zrna Mo. Ispitivanja su pokazala da VPS - Mo slojevi prevlake imaju mehaničke karakteristike i mikrostrukturu koje u potpunosti omogućavaju primenu prevlake na površinama delova od kojih se zahteva da imaju dobra klizna svojstva, otpornost na habanje i koroziju.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Mechanical properties and microstructure of molybdenum coating layers deposited vacuum plasma spray process
T1  - Mehanička svojstva i mikrostruktura slojeva prevlake molibdena deponovane vakuum plazma sprej procesom
EP  - 276
IS  - 3
SP  - 271
VL  - 60
DO  - 10.5937/zasmat1903271M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Veljić, Darko and Bajić, Nikola",
year = "2019",
abstract = "Molybdenum coatings due to their excellent wear resistant properties and sliding characteristics under dry friction conditions are often used in applications to resist friction and dry sliding. Since molybdenum metal is susceptible to oxidation, in this study, the molybdenum coating layers were successfully deposited at low pressure inert gas Ar using vacuum plasma spray technology (VPS). Characterization of the Mo coating was performed by measuring the microhardness of the coating layers using the Vickers HV0.3 method, the bond strength by tensile testing and the microstructure by optical microscopy (OM) and scanning electron microscopy (SEM). The microstructure of the coating layers was tested in deposited stateand after etching. The etching reagent used was NH3·H2O and H2O2 with a volume ratio of 1:2. The results showed that the coating has good mechanical properties, microhardness and high adhesion/cohesion strength. Layers of VPS - Mo coatings were composed of well-melted powder particles, partially unmelted particles with a good bond in the coating layers and micropores with a share below 0.5%. It was found that the microstructure of the coating consists mainly of lamellar structure and columnar crystal Mo grains. Tests have shown that the VPS - Mo coating layers have mechanical characteristics and a microstructure which fully enables the use of the coating on surfaces of parts which are required to have good sliding properties, resistance to wear and corrosion., Prevlake molibdena se zbog svojih odličnih osobina na habanje i kliznih svojstva u uslovima suvog trenja često koriste u aplikacijama da se odupru trenju i suvom klizanju. Pošto je molibden metal osetljiv na oksidaciju, u ovoj studiji slojevi prevlake molibdena su uspešno deponovani na niskom pritisku inertnog gasa Ar vacuum plazma sprej tehnologijom (VPS). Karakterizacija prevlake Mo je izvršena merenjem mikrotvrdoće slojeva prevlake metodom Vickers HV0.3, čvrstoće spoja ispitivanjem na zatezanje i mikrostrukture metodom optičke mikroskopije (OM) i skening elektronske mikroskopije (SEM). Mikrostruktura slojeva prevlake je ispitana u deponovanom stanju i posle nagrizanja. Za nagrizanje se koristio reagens NH3·H2O i H2O2 sa zapreminskim odnosom 1:2. Dobijeni rezultati su pokazali da prevlaka ima dobre mehaničke karakteristike, mikrotvrdoću i visoku adheziono / kohezionu čvrstoću. Slojevi VPS - Mo prevlake su se sastojali od dobro istopljenih čestica praha, delimično neistopljenih čestica sa dobrom vezom u slojevima prevlake i mikro pora sa udelom ispod 0,5%. Utvrđeno je da se mikrostruktura prevlake uglavnom sastoji od lamelarne strukture i stubastih kristalnih zrna Mo. Ispitivanja su pokazala da VPS - Mo slojevi prevlake imaju mehaničke karakteristike i mikrostrukturu koje u potpunosti omogućavaju primenu prevlake na površinama delova od kojih se zahteva da imaju dobra klizna svojstva, otpornost na habanje i koroziju.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Mechanical properties and microstructure of molybdenum coating layers deposited vacuum plasma spray process, Mehanička svojstva i mikrostruktura slojeva prevlake molibdena deponovane vakuum plazma sprej procesom",
pages = "276-271",
number = "3",
volume = "60",
doi = "10.5937/zasmat1903271M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M., Veljić, D.,& Bajić, N.. (2019). Mechanical properties and microstructure of molybdenum coating layers deposited vacuum plasma spray process. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 60(3), 271-276.
https://doi.org/10.5937/zasmat1903271M

Mrdak M, Lačnjevac Č, Rakin M, Veljić D, Bajić N. Mechanical properties and microstructure of molybdenum coating layers deposited vacuum plasma spray process. in Zaštita materijala. 2019;60(3):271-276.
doi:10.5937/zasmat1903271M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Veljić, Darko, Bajić, Nikola, "Mechanical properties and microstructure of molybdenum coating layers deposited vacuum plasma spray process" in Zaštita materijala, 60, no. 3 (2019):271-276,
https://doi.org/10.5937/zasmat1903271M . .

TY  - JOUR
AU  - Vencl, Aleksandar A.
AU  - Mrdak, Mihailo
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4120
AB  - The aim of this study was to investigate the thermal cycling behaviour of NiCr-Al-Co-Y2O3 bond coating in thermal barrier coating (TBC) system with ZrO2-MgO as a top coating. The coatings were deposited by atmospheric plasma spraying (APS) on stainless steel X15Cr13 (EN 1.4024) substrate. The used composite powder NiCr-Al-Co-Y2O3 was mechanically cladded, and the steel substrates were preheated to 160-180 degrees C. The thermal cycling performance of the obtained bond coat and the effect of formed complex ceramic oxides of the Al2O3-Y2O3 system were tested by heating to 1200 degrees C and cooling in air to 160-180 degrees C. The number of performed thermal cycles was 7, 32 and 79. The quality of the obtained coating, as well as its thermal cycling behaviour, was assessed through the microstructural analysis, microhardness and tensile bond strength measurements, and change in chemical composition and microhardness. The obtained results showed that the steel substrate, bond coat oxidation and interdiffusion at bond coat/substrate interface have a significant influence on changes in chemical composition and microhardness of the bond coat. The correlation between oxidation behaviour of NiCr-Al-Co-Y2O3 bond coat and number of thermal cycles was also discussed.
PB  - Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd
T2  - Thermal Science
T1  - Thermal cycling behaviour of plasma sprayed nicr-al-co-y2o3 bond coat in thermal barrier coating system
EP  - S1800
SP  - S1789
VL  - 23
DO  - 10.2298/TSCI180302374V
ER  - 

@article{
author = "Vencl, Aleksandar A. and Mrdak, Mihailo",
year = "2019",
abstract = "The aim of this study was to investigate the thermal cycling behaviour of NiCr-Al-Co-Y2O3 bond coating in thermal barrier coating (TBC) system with ZrO2-MgO as a top coating. The coatings were deposited by atmospheric plasma spraying (APS) on stainless steel X15Cr13 (EN 1.4024) substrate. The used composite powder NiCr-Al-Co-Y2O3 was mechanically cladded, and the steel substrates were preheated to 160-180 degrees C. The thermal cycling performance of the obtained bond coat and the effect of formed complex ceramic oxides of the Al2O3-Y2O3 system were tested by heating to 1200 degrees C and cooling in air to 160-180 degrees C. The number of performed thermal cycles was 7, 32 and 79. The quality of the obtained coating, as well as its thermal cycling behaviour, was assessed through the microstructural analysis, microhardness and tensile bond strength measurements, and change in chemical composition and microhardness. The obtained results showed that the steel substrate, bond coat oxidation and interdiffusion at bond coat/substrate interface have a significant influence on changes in chemical composition and microhardness of the bond coat. The correlation between oxidation behaviour of NiCr-Al-Co-Y2O3 bond coat and number of thermal cycles was also discussed.",
publisher = "Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd",
journal = "Thermal Science",
title = "Thermal cycling behaviour of plasma sprayed nicr-al-co-y2o3 bond coat in thermal barrier coating system",
pages = "S1800-S1789",
volume = "23",
doi = "10.2298/TSCI180302374V"
}

Vencl, A. A.,& Mrdak, M.. (2019). Thermal cycling behaviour of plasma sprayed nicr-al-co-y2o3 bond coat in thermal barrier coating system. in Thermal Science
Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd., 23, S1789-S1800.
https://doi.org/10.2298/TSCI180302374V

Vencl AA, Mrdak M. Thermal cycling behaviour of plasma sprayed nicr-al-co-y2o3 bond coat in thermal barrier coating system. in Thermal Science. 2019;23:S1789-S1800.
doi:10.2298/TSCI180302374V .

Vencl, Aleksandar A., Mrdak, Mihailo, "Thermal cycling behaviour of plasma sprayed nicr-al-co-y2o3 bond coat in thermal barrier coating system" in Thermal Science, 23 (2019):S1789-S1800,
https://doi.org/10.2298/TSCI180302374V . .

TY  - CONF
AU  - Mrdak, Mihailo
AU  - Rakin, Marko
AU  - Bajić, Nikola
AU  - Veljić, Darko
AU  - Pekez, Jasmina
AU  - Karastojković, Zoran
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6337
AB  - The plasma spray coatings are subject to high influence of surface loads, corrosion, and temperatures
which cause damage in the form of separation of the coating from the substrate or flacking of the coating from
the substrate edges. Adhesion is the main factor that opposes the influence of the external loads, and defines the
quality of the bond of the coating with the substrate. Each type of coating has a determined quality of adhesion
as per appropriate standard in order to meet functional properties during operation.
There is no universal coating test for all types of the coatings, the test is chosen depending on the technology
used for the production of the coating, the type of material from which it was made and its thickness. One of the
many tests that are used for assessment of adhesion / cohesion strength of plasma spray coatings is the scratch
test. The aim of this paper was to evaluate the cohesive / adhesive strength of the plasma spray
Ni22Cr10Al1Yalloycoating. The testing was conducted using the Rockwell C diamond indenter with a tip radius
of 200 µm. The results showed that the scratch test is an efficient method for assessment of adhesion and
cohesion of plasma spray coatings.
PB  - University of Novi Sad Technical faculty “Mihajlo Pupin” Zrenjanin, Republic of Serbia
C3  - VIII International Conference Industrial Engineering and Environmental Protection
T1  - Determining the adhesion / cohesion strength of plasma spray coatings using the Rockwell - c method
EP  - 122
SP  - 119
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6337
ER  - 

@conference{
author = "Mrdak, Mihailo and Rakin, Marko and Bajić, Nikola and Veljić, Darko and Pekez, Jasmina and Karastojković, Zoran",
year = "2018",
abstract = "The plasma spray coatings are subject to high influence of surface loads, corrosion, and temperatures
which cause damage in the form of separation of the coating from the substrate or flacking of the coating from
the substrate edges. Adhesion is the main factor that opposes the influence of the external loads, and defines the
quality of the bond of the coating with the substrate. Each type of coating has a determined quality of adhesion
as per appropriate standard in order to meet functional properties during operation.
There is no universal coating test for all types of the coatings, the test is chosen depending on the technology
used for the production of the coating, the type of material from which it was made and its thickness. One of the
many tests that are used for assessment of adhesion / cohesion strength of plasma spray coatings is the scratch
test. The aim of this paper was to evaluate the cohesive / adhesive strength of the plasma spray
Ni22Cr10Al1Yalloycoating. The testing was conducted using the Rockwell C diamond indenter with a tip radius
of 200 µm. The results showed that the scratch test is an efficient method for assessment of adhesion and
cohesion of plasma spray coatings.",
publisher = "University of Novi Sad Technical faculty “Mihajlo Pupin” Zrenjanin, Republic of Serbia",
journal = "VIII International Conference Industrial Engineering and Environmental Protection",
title = "Determining the adhesion / cohesion strength of plasma spray coatings using the Rockwell - c method",
pages = "122-119",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6337"
}

Mrdak, M., Rakin, M., Bajić, N., Veljić, D., Pekez, J.,& Karastojković, Z.. (2018). Determining the adhesion / cohesion strength of plasma spray coatings using the Rockwell - c method. in VIII International Conference Industrial Engineering and Environmental Protection
University of Novi Sad Technical faculty “Mihajlo Pupin” Zrenjanin, Republic of Serbia., 119-122.
https://hdl.handle.net/21.15107/rcub_technorep_6337

Mrdak M, Rakin M, Bajić N, Veljić D, Pekez J, Karastojković Z. Determining the adhesion / cohesion strength of plasma spray coatings using the Rockwell - c method. in VIII International Conference Industrial Engineering and Environmental Protection. 2018;:119-122.
https://hdl.handle.net/21.15107/rcub_technorep_6337 .

Mrdak, Mihailo, Rakin, Marko, Bajić, Nikola, Veljić, Darko, Pekez, Jasmina, Karastojković, Zoran, "Determining the adhesion / cohesion strength of plasma spray coatings using the Rockwell - c method" in VIII International Conference Industrial Engineering and Environmental Protection (2018):119-122,
https://hdl.handle.net/21.15107/rcub_technorep_6337 .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
AU  - Bajić, Nikola
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3821
AB  - Tantalum is a very popular material for the industry as a whole because of very important characteristics such as: high melting point, significant thermal and electrical conductivity, high toughness and resistance to corrosion and good biocompatibility. Since the tantalum metal is sensitive to O, N and H gases, tantalum coating layers are deposited only using the vacuum plasma spray process (VPS), which has, in the past few years been used successfully for preparing coatings which are widely used in the preparation of metal implants. The aim of this paper was to, at a low pressure inert gas eliminate the influence of the surrounding atmosphere on the melted Ta powder particles and produce coatings with mechanical and structural characteristics which will find application in biomedicine. For depositing the coating a commercial tantalum powder AMPERIT® 151065 grain size of 10 - 30 μm was used. The powder was deposited with a plasma F4 gun at a distance of substrates at 300 mm. The Ta coating layers were deposited with a thickness of 60 to 70 μm on steel substrates. As the plasma gas used was a mixture of Ar and He inert gases. The microhardness of the coating was tested using the HV0.3 method and the tensile strength of the coatings bond was tested by the tensile method in accordance with the ASTM C633-1 standard. The microstructure of the coating in deposited state and after etching was studied on an optical microscope (OM) and scanning electron microscope (SEM). Etching the coating was carried out in the reagent which consisted of two parts of nitric acid, two parts hydrofluoric acid, and five parts water (2HNO3: 2HF: 5H2O). The structure of the coating consists solely of a tough αTa phase with a body centered cubic lattice. Tests have shown that layers of VPS - Ta coatings have the microstructure and mechanical properties which completely support the use of the coating in the process of making implants.
AB  - Tantal je veoma atraktivan materijal za industriju u celini zbog veoma bitnih osobina kao što su: visoka temperatura topljenja, značajna toplotna i električna provodljivost, visoka žilavost i otpornost na koroziju i dobra biokompatibilnost. Pošto je tantal metal osetljiv na gasove O, N i H, slojevi prevlake tantala se isključivo deponuju vakuum plazma sprej procesom (VPS), koji se u poslednjih nekoliko godina uspešno koristi za izradu prevlaka koje imaju široku primenu u izradi metalnih implanata. Cilj rada bio je da se na niskom pritisku inertnog gasa eliminiše uticaj okolne atmosfere na istopljene čestice praha Ta i proizvedu prevlake mehaničkih i strukturnih karakteristika koje će naći primenu u biomedicini. Za deponovanje prevlake koristio se komercijalni prah tantala AMPERIT® 151.065 granulacije od 10 - 30µm. Prah je deponovan sa plazma pištoljem F4 na odstojanju podloge od 300 mm. Slojevi Ta prevlaka su deponovani sa debljinom od 60 do 70µm na čeličnim podlogama. Kao plazma gas koristila se mešavina inertnih gasova Ar i He. Mikrotvrdoća prevlake ispitana je metodom HV0.3 a zatezna čvrstoća spoja prevlake ispitana je metodom na zatezanje u skladu sa standardom ASTM C633-1. Mikrostruktura prevlake u deponovnom stanju i u stanju posle nagrizanja ispitana je na optičkom mikroskopu (OM) i na skening elektronskom mikroskopu (SEM). Nagrizanje prevlake sprovedeno je u reagensu koji se sastojao od dva dela azotne kiseline, dva dela fluorovodonične kiseline i pet delova vode (2HNO3 : 2HF : 5H2O). Struktura prevlake se isključivo sastoji od žilave α-Ta faze sa zapreminski centriranom kubnom rešetkom. Ispitivanja su pokazala da slojevi VPS - Ta prevlake imaju mikrostrukturu i mehaničke karakteristike koje u potpunosti omogućavaju primenu prevlake u procesu izrade implanata.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Characterization of tantalum coatings deposited using vacuum plasma spray process
T1  - Karakterizacija tantal prevlake deponovane vakuum plazma sprej procesom
EP  - 494
IS  - 4
SP  - 489
VL  - 59
DO  - 10.5937/zasmat1804489M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko and Bajić, Nikola",
year = "2018",
abstract = "Tantalum is a very popular material for the industry as a whole because of very important characteristics such as: high melting point, significant thermal and electrical conductivity, high toughness and resistance to corrosion and good biocompatibility. Since the tantalum metal is sensitive to O, N and H gases, tantalum coating layers are deposited only using the vacuum plasma spray process (VPS), which has, in the past few years been used successfully for preparing coatings which are widely used in the preparation of metal implants. The aim of this paper was to, at a low pressure inert gas eliminate the influence of the surrounding atmosphere on the melted Ta powder particles and produce coatings with mechanical and structural characteristics which will find application in biomedicine. For depositing the coating a commercial tantalum powder AMPERIT® 151065 grain size of 10 - 30 μm was used. The powder was deposited with a plasma F4 gun at a distance of substrates at 300 mm. The Ta coating layers were deposited with a thickness of 60 to 70 μm on steel substrates. As the plasma gas used was a mixture of Ar and He inert gases. The microhardness of the coating was tested using the HV0.3 method and the tensile strength of the coatings bond was tested by the tensile method in accordance with the ASTM C633-1 standard. The microstructure of the coating in deposited state and after etching was studied on an optical microscope (OM) and scanning electron microscope (SEM). Etching the coating was carried out in the reagent which consisted of two parts of nitric acid, two parts hydrofluoric acid, and five parts water (2HNO3: 2HF: 5H2O). The structure of the coating consists solely of a tough αTa phase with a body centered cubic lattice. Tests have shown that layers of VPS - Ta coatings have the microstructure and mechanical properties which completely support the use of the coating in the process of making implants., Tantal je veoma atraktivan materijal za industriju u celini zbog veoma bitnih osobina kao što su: visoka temperatura topljenja, značajna toplotna i električna provodljivost, visoka žilavost i otpornost na koroziju i dobra biokompatibilnost. Pošto je tantal metal osetljiv na gasove O, N i H, slojevi prevlake tantala se isključivo deponuju vakuum plazma sprej procesom (VPS), koji se u poslednjih nekoliko godina uspešno koristi za izradu prevlaka koje imaju široku primenu u izradi metalnih implanata. Cilj rada bio je da se na niskom pritisku inertnog gasa eliminiše uticaj okolne atmosfere na istopljene čestice praha Ta i proizvedu prevlake mehaničkih i strukturnih karakteristika koje će naći primenu u biomedicini. Za deponovanje prevlake koristio se komercijalni prah tantala AMPERIT® 151.065 granulacije od 10 - 30µm. Prah je deponovan sa plazma pištoljem F4 na odstojanju podloge od 300 mm. Slojevi Ta prevlaka su deponovani sa debljinom od 60 do 70µm na čeličnim podlogama. Kao plazma gas koristila se mešavina inertnih gasova Ar i He. Mikrotvrdoća prevlake ispitana je metodom HV0.3 a zatezna čvrstoća spoja prevlake ispitana je metodom na zatezanje u skladu sa standardom ASTM C633-1. Mikrostruktura prevlake u deponovnom stanju i u stanju posle nagrizanja ispitana je na optičkom mikroskopu (OM) i na skening elektronskom mikroskopu (SEM). Nagrizanje prevlake sprovedeno je u reagensu koji se sastojao od dva dela azotne kiseline, dva dela fluorovodonične kiseline i pet delova vode (2HNO3 : 2HF : 5H2O). Struktura prevlake se isključivo sastoji od žilave α-Ta faze sa zapreminski centriranom kubnom rešetkom. Ispitivanja su pokazala da slojevi VPS - Ta prevlake imaju mikrostrukturu i mehaničke karakteristike koje u potpunosti omogućavaju primenu prevlake u procesu izrade implanata.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Characterization of tantalum coatings deposited using vacuum plasma spray process, Karakterizacija tantal prevlake deponovane vakuum plazma sprej procesom",
pages = "494-489",
number = "4",
volume = "59",
doi = "10.5937/zasmat1804489M"
}

Mrdak, M., Lačnjevac, Č., Rakin, M.,& Bajić, N.. (2018). Characterization of tantalum coatings deposited using vacuum plasma spray process. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 59(4), 489-494.
https://doi.org/10.5937/zasmat1804489M

Mrdak M, Lačnjevac Č, Rakin M, Bajić N. Characterization of tantalum coatings deposited using vacuum plasma spray process. in Zaštita materijala. 2018;59(4):489-494.
doi:10.5937/zasmat1804489M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, Bajić, Nikola, "Characterization of tantalum coatings deposited using vacuum plasma spray process" in Zaštita materijala, 59, no. 4 (2018):489-494,
https://doi.org/10.5937/zasmat1804489M . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Lačnjevac, Časlav
AU  - Rakin, Marko
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3836
AB  - In this paper analyzed was the influence of implementation of inert Ar gas and a mixture of inert plasma Ar / He gases in a vacuum chamber on the deposition of reactive niobium (Nb) powder. The aim of this paper was to deposit coating layers of high density, without oxide content, that will find application in the field of biomedicine. Detailed examination was performed of mechanical properties of microhardness using the HV0.3 method, of tensile bond strength by tensile testing and of the microstructure of the coating layers in the deposited state and after etching. For etching a solution of nitric acid HNO3 and hydrofluoric acid HF in a ratio of 1:1was used. It was found that inert gases, at low pressure prevent the reaction of gases with the metal droplets of molten Nb powder particles during the plasma spray deposition process. The density of the deposited coating in vacuum chamber is higher than that of coatings which are deposited at atmospheric pressure with reactive plasma gases N2 and H2. This is attributed to the elimination of thin oxide and nitride films at the interlamellar Nb contact, substantially increasing the ductility of the coating, eliminating the micro cracks through the deposited layers, which was confirmed by metallographic examination of samples. Tests have shown that VPS - Nb coating layers have mechanical properties and microstructure which completely enable the use of the coating on implants.
AB  - U ovom radu ispitan je uticaj primene inertnog gasa Ar i mešavine inertnih plazma gasova Ar / He u vakuum komori na depoziciju reaktivnog praha niobijuma (Nb). Cilj rada je bio da se deponuju slojevi prevlake visoke gustine bez sadržaja oksida koji će naći primenu u oblasti biomedicine. Izvršena su detaljna ispitavanja mehaničkih karakteristika mikrotvrdoće metodom HV0.3 i zatezne čvrstoće spoja ispitivanjem na zatezanje i mikrostrukture slojeva prevlake u deponovanom stanju i posle nagrizanja. Za nagrizanje se koristio rastvor azotne kiseline HNO3 i fluorovodoniče kiseline HF u odnosu 1 : 1. Utvrđeno je da inertni gasovi na niskom pritisku sprečavaju reakciju gasova sa metalnim kapima istopljenih čestica praha Nb tokom plazma sprej depozicije. Gustina deponovane prevlake u vakuumu je veća u odnosu na prevlake koje se deponuju na atmosferskom pritisku sa reaktivnim plazma gasovima N2 i H2. Ovo se pripisuje eliminisanju tankih filmova oksida i nitrida na međulamelarnim kontaktnim Nb, što značajno povećava duktilnost prevlake, eliminišući mikro pukotine kroz deponovane slojeve, što su potvrdila metalografska ispitivanja uzoraka. Ispitivanja su pokazala da slojevi VPS - Nb prevlake imaju mehaničke karakteristike i mikrostrukturu, koje u potpunosti omogućavaju primenu prevlake na implantima.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Mechanical and structural features of Nb coating layers deposited on steel substrates in a vacuum chamber
T1  - Mehaničke i strukturne karakteristike slojeva prevlake Nb deponovane u vakuumu
EP  - 172
IS  - 2
SP  - 167
VL  - 59
DO  - 10.5937/ZasMat1802167M
ER  - 

@article{
author = "Mrdak, Mihailo and Lačnjevac, Časlav and Rakin, Marko",
year = "2018",
abstract = "In this paper analyzed was the influence of implementation of inert Ar gas and a mixture of inert plasma Ar / He gases in a vacuum chamber on the deposition of reactive niobium (Nb) powder. The aim of this paper was to deposit coating layers of high density, without oxide content, that will find application in the field of biomedicine. Detailed examination was performed of mechanical properties of microhardness using the HV0.3 method, of tensile bond strength by tensile testing and of the microstructure of the coating layers in the deposited state and after etching. For etching a solution of nitric acid HNO3 and hydrofluoric acid HF in a ratio of 1:1was used. It was found that inert gases, at low pressure prevent the reaction of gases with the metal droplets of molten Nb powder particles during the plasma spray deposition process. The density of the deposited coating in vacuum chamber is higher than that of coatings which are deposited at atmospheric pressure with reactive plasma gases N2 and H2. This is attributed to the elimination of thin oxide and nitride films at the interlamellar Nb contact, substantially increasing the ductility of the coating, eliminating the micro cracks through the deposited layers, which was confirmed by metallographic examination of samples. Tests have shown that VPS - Nb coating layers have mechanical properties and microstructure which completely enable the use of the coating on implants., U ovom radu ispitan je uticaj primene inertnog gasa Ar i mešavine inertnih plazma gasova Ar / He u vakuum komori na depoziciju reaktivnog praha niobijuma (Nb). Cilj rada je bio da se deponuju slojevi prevlake visoke gustine bez sadržaja oksida koji će naći primenu u oblasti biomedicine. Izvršena su detaljna ispitavanja mehaničkih karakteristika mikrotvrdoće metodom HV0.3 i zatezne čvrstoće spoja ispitivanjem na zatezanje i mikrostrukture slojeva prevlake u deponovanom stanju i posle nagrizanja. Za nagrizanje se koristio rastvor azotne kiseline HNO3 i fluorovodoniče kiseline HF u odnosu 1 : 1. Utvrđeno je da inertni gasovi na niskom pritisku sprečavaju reakciju gasova sa metalnim kapima istopljenih čestica praha Nb tokom plazma sprej depozicije. Gustina deponovane prevlake u vakuumu je veća u odnosu na prevlake koje se deponuju na atmosferskom pritisku sa reaktivnim plazma gasovima N2 i H2. Ovo se pripisuje eliminisanju tankih filmova oksida i nitrida na međulamelarnim kontaktnim Nb, što značajno povećava duktilnost prevlake, eliminišući mikro pukotine kroz deponovane slojeve, što su potvrdila metalografska ispitivanja uzoraka. Ispitivanja su pokazala da slojevi VPS - Nb prevlake imaju mehaničke karakteristike i mikrostrukturu, koje u potpunosti omogućavaju primenu prevlake na implantima.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Mechanical and structural features of Nb coating layers deposited on steel substrates in a vacuum chamber, Mehaničke i strukturne karakteristike slojeva prevlake Nb deponovane u vakuumu",
pages = "172-167",
number = "2",
volume = "59",
doi = "10.5937/ZasMat1802167M"
}

Mrdak, M., Lačnjevac, Č.,& Rakin, M.. (2018). Mechanical and structural features of Nb coating layers deposited on steel substrates in a vacuum chamber. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 59(2), 167-172.
https://doi.org/10.5937/ZasMat1802167M

Mrdak M, Lačnjevac Č, Rakin M. Mechanical and structural features of Nb coating layers deposited on steel substrates in a vacuum chamber. in Zaštita materijala. 2018;59(2):167-172.
doi:10.5937/ZasMat1802167M .

Mrdak, Mihailo, Lačnjevac, Časlav, Rakin, Marko, "Mechanical and structural features of Nb coating layers deposited on steel substrates in a vacuum chamber" in Zaštita materijala, 59, no. 2 (2018):167-172,
https://doi.org/10.5937/ZasMat1802167M . .

TY  - JOUR
AU  - Mrdak, Mihailo
AU  - Rakin, Marko
AU  - Međo, Bojan
AU  - Bajić, Nikola
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3016
AB  - The aim of this study was to improve the resistance of turbo jet engine parts exposed to high temperatures and overheating and sudden changes in temperature. For this purpose, three thermal barrier coating (TBC) systems NiCrAlCoY2O3/ZrO2MgO, NiCrAlCoY2O3/ZrO2Y2O3 and NiCrAlCoY2O3/ZrO2CeO2Y2O3 were tested. They were deposited using the atmospheric plasma spray process (APS). In order to develop a TBC with the best thermal insulating properties and the highest reliability in relation to aging of materials under the influence of sudden changes in temperature, TBC systems that were deposited on cold and preheated substrates were tested. The network of microcracks on the surfaces of the ceramic layers in deposited condition was analyzed using scanning electron microscopy (SEM). Insulating characteristics of TBC systems were examined by measuring the temperature difference Delta T between the top and bottom surfaces of the samples at a temperature of 1200 degrees C. Testing of TBC for resistance to thermal cyclic behaviour was performed by exposing samples to alternate heating at 1200 degrees C and rapid cooling of the samples to 180 degrees C. Microhardnesses of the TBC system, after completion of thermal cycles, were compared with the values in deposited state. Analyses of thermal insulation properties and thermal cyclic behaviour have shown a correlation between the substrate temperature and quality of the TBC system in thermal cyclic conditions.
PB  - Elsevier Sci Ltd, Oxford
T2  - Materials & Design
T1  - Experimental study of insulating properties and behaviour of thermal barrier coating systems in thermo cyclic conditions
EP  - 343
SP  - 337
VL  - 67
DO  - 10.1016/j.matdes.2014.11.029
ER  - 

@article{
author = "Mrdak, Mihailo and Rakin, Marko and Međo, Bojan and Bajić, Nikola",
year = "2015",
abstract = "The aim of this study was to improve the resistance of turbo jet engine parts exposed to high temperatures and overheating and sudden changes in temperature. For this purpose, three thermal barrier coating (TBC) systems NiCrAlCoY2O3/ZrO2MgO, NiCrAlCoY2O3/ZrO2Y2O3 and NiCrAlCoY2O3/ZrO2CeO2Y2O3 were tested. They were deposited using the atmospheric plasma spray process (APS). In order to develop a TBC with the best thermal insulating properties and the highest reliability in relation to aging of materials under the influence of sudden changes in temperature, TBC systems that were deposited on cold and preheated substrates were tested. The network of microcracks on the surfaces of the ceramic layers in deposited condition was analyzed using scanning electron microscopy (SEM). Insulating characteristics of TBC systems were examined by measuring the temperature difference Delta T between the top and bottom surfaces of the samples at a temperature of 1200 degrees C. Testing of TBC for resistance to thermal cyclic behaviour was performed by exposing samples to alternate heating at 1200 degrees C and rapid cooling of the samples to 180 degrees C. Microhardnesses of the TBC system, after completion of thermal cycles, were compared with the values in deposited state. Analyses of thermal insulation properties and thermal cyclic behaviour have shown a correlation between the substrate temperature and quality of the TBC system in thermal cyclic conditions.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Materials & Design",
title = "Experimental study of insulating properties and behaviour of thermal barrier coating systems in thermo cyclic conditions",
pages = "343-337",
volume = "67",
doi = "10.1016/j.matdes.2014.11.029"
}

Mrdak, M., Rakin, M., Međo, B.,& Bajić, N.. (2015). Experimental study of insulating properties and behaviour of thermal barrier coating systems in thermo cyclic conditions. in Materials & Design
Elsevier Sci Ltd, Oxford., 67, 337-343.
https://doi.org/10.1016/j.matdes.2014.11.029

Mrdak M, Rakin M, Međo B, Bajić N. Experimental study of insulating properties and behaviour of thermal barrier coating systems in thermo cyclic conditions. in Materials & Design. 2015;67:337-343.
doi:10.1016/j.matdes.2014.11.029 .

Mrdak, Mihailo, Rakin, Marko, Međo, Bojan, Bajić, Nikola, "Experimental study of insulating properties and behaviour of thermal barrier coating systems in thermo cyclic conditions" in Materials & Design, 67 (2015):337-343,
https://doi.org/10.1016/j.matdes.2014.11.029 . .

TY  - JOUR
AU  - Bajić, Nikola
AU  - Veljić, Darko
AU  - Rakin, Marko
AU  - Stojadinović, Slobodan
AU  - Pekez, Jasmina
AU  - Mrdak, Mihailo
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2615
PB  - DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd
T2  - Zavarivanje i zavarene konstrukcije
T1  - Experimental laboratory for development of fillers and auxiliary materials for welding and soldering (2)
T1  - Eksperimentalna laboratorija za razvoj dodatnih i pomoćnih materijala za zavarivanje i lemljenje (2)
EP  - 9
IS  - 1
SP  - 5
VL  - 59
DO  - 10.5937/zzk1401005B
ER  - 

@article{
author = "Bajić, Nikola and Veljić, Darko and Rakin, Marko and Stojadinović, Slobodan and Pekez, Jasmina and Mrdak, Mihailo",
year = "2014",
publisher = "DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd",
journal = "Zavarivanje i zavarene konstrukcije",
title = "Experimental laboratory for development of fillers and auxiliary materials for welding and soldering (2), Eksperimentalna laboratorija za razvoj dodatnih i pomoćnih materijala za zavarivanje i lemljenje (2)",
pages = "9-5",
number = "1",
volume = "59",
doi = "10.5937/zzk1401005B"
}

Bajić, N., Veljić, D., Rakin, M., Stojadinović, S., Pekez, J.,& Mrdak, M.. (2014). Experimental laboratory for development of fillers and auxiliary materials for welding and soldering (2). in Zavarivanje i zavarene konstrukcije
DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd., 59(1), 5-9.
https://doi.org/10.5937/zzk1401005B

Bajić N, Veljić D, Rakin M, Stojadinović S, Pekez J, Mrdak M. Experimental laboratory for development of fillers and auxiliary materials for welding and soldering (2). in Zavarivanje i zavarene konstrukcije. 2014;59(1):5-9.
doi:10.5937/zzk1401005B .

Bajić, Nikola, Veljić, Darko, Rakin, Marko, Stojadinović, Slobodan, Pekez, Jasmina, Mrdak, Mihailo, "Experimental laboratory for development of fillers and auxiliary materials for welding and soldering (2)" in Zavarivanje i zavarene konstrukcije, 59, no. 1 (2014):5-9,
https://doi.org/10.5937/zzk1401005B . .

TY  - JOUR
AU  - Bajić, Nikola
AU  - Rakin, Marko
AU  - Veljić, Darko
AU  - Mrdak, Mihailo
AU  - Stojadinović, Slobodan
AU  - Pekez, Jasmina
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2617
AB  - This paper presents the results related to organizing production of flux-cored wire alloyed with Ni and Mo according to standard AWS A5.29 intended for the MAG welding process. On the experimental line for steel strip calibration and production of flux-cored wire two batches of flux-cored wire were produced with a constant Mo and Ni content at two levels (1.2% Ni in one and 2.6% Ni in the other batch). Experimental welding of steel plate samples was performed using the MAG process with two qualities of cored wire. Testing the structure and quality of the weld metal was done in order to optimize content of Ni in the alloyed flux-cored wire intended for welding fine grained micro-alloyed steels. Based on the analysis of test results of the microstructure and EDS analysis of the structure of welded samples and test results of tensile properties and impact energy, conclusions were made about the optimal content of Ni in the weld metal, and thus the choice of quality of flux-cored wire.
AB  - U radu su dati rezultati vezani za osvajanje proizvodnje punjene žice legirane sa Ni i Mo prema standardu AWS A5.29 namenjeno za MAG postupak zavarivanja. Na eksperimentalnoj liniji za kalibraciju čelične trake i izradu punjene žice proizvedene su dve šarže punjene žice sa konstantnim sadržajem Mo i sadržajem Ni na dva nivoa (1.2%Ni kod jedne i 2.6%Ni kod druge šarže). Eksperimentalno zavarivanje uzoraka čeličnih ploča je izvedeno MAG postupkom sa dva kvaliteta punjene žice. Ispitivanje strukture i kvaliteta metala šava je izvedeno u cilju optimizacije sadržaja Ni u legiranoj punjenoj žici koja je namenjena za zavarivanje sitnozrnih mikrolegiranih čelika. Na osnovu analize dobijenih rezultata ispitivanja mikrostrukture i EDS analize strukture zavarenih uzoraka i rezultata ispitivanja zateznih karakteristika energije udara, dati su zaključci o optimalnom sadržaju Ni u metalu šava, a time i izboru kvaliteta punjene žice.
PB  - DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd
T2  - Zavarivanje i zavarene konstrukcije
T1  - Optimizing the content of nickel in flux-cored wire intended for welding micro-alloyed steels
T1  - Optimizacija sadržaja nikla u punjenoj žici namenjenoj za zavarivanje mikrolegiranih čelika
EP  - 67
IS  - 2
SP  - 61
VL  - 59
DO  - 10.5937/zzk1402061B
ER  - 

@article{
author = "Bajić, Nikola and Rakin, Marko and Veljić, Darko and Mrdak, Mihailo and Stojadinović, Slobodan and Pekez, Jasmina",
year = "2014",
abstract = "This paper presents the results related to organizing production of flux-cored wire alloyed with Ni and Mo according to standard AWS A5.29 intended for the MAG welding process. On the experimental line for steel strip calibration and production of flux-cored wire two batches of flux-cored wire were produced with a constant Mo and Ni content at two levels (1.2% Ni in one and 2.6% Ni in the other batch). Experimental welding of steel plate samples was performed using the MAG process with two qualities of cored wire. Testing the structure and quality of the weld metal was done in order to optimize content of Ni in the alloyed flux-cored wire intended for welding fine grained micro-alloyed steels. Based on the analysis of test results of the microstructure and EDS analysis of the structure of welded samples and test results of tensile properties and impact energy, conclusions were made about the optimal content of Ni in the weld metal, and thus the choice of quality of flux-cored wire., U radu su dati rezultati vezani za osvajanje proizvodnje punjene žice legirane sa Ni i Mo prema standardu AWS A5.29 namenjeno za MAG postupak zavarivanja. Na eksperimentalnoj liniji za kalibraciju čelične trake i izradu punjene žice proizvedene su dve šarže punjene žice sa konstantnim sadržajem Mo i sadržajem Ni na dva nivoa (1.2%Ni kod jedne i 2.6%Ni kod druge šarže). Eksperimentalno zavarivanje uzoraka čeličnih ploča je izvedeno MAG postupkom sa dva kvaliteta punjene žice. Ispitivanje strukture i kvaliteta metala šava je izvedeno u cilju optimizacije sadržaja Ni u legiranoj punjenoj žici koja je namenjena za zavarivanje sitnozrnih mikrolegiranih čelika. Na osnovu analize dobijenih rezultata ispitivanja mikrostrukture i EDS analize strukture zavarenih uzoraka i rezultata ispitivanja zateznih karakteristika energije udara, dati su zaključci o optimalnom sadržaju Ni u metalu šava, a time i izboru kvaliteta punjene žice.",
publisher = "DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd",
journal = "Zavarivanje i zavarene konstrukcije",
title = "Optimizing the content of nickel in flux-cored wire intended for welding micro-alloyed steels, Optimizacija sadržaja nikla u punjenoj žici namenjenoj za zavarivanje mikrolegiranih čelika",
pages = "67-61",
number = "2",
volume = "59",
doi = "10.5937/zzk1402061B"
}

Bajić, N., Rakin, M., Veljić, D., Mrdak, M., Stojadinović, S.,& Pekez, J.. (2014). Optimizing the content of nickel in flux-cored wire intended for welding micro-alloyed steels. in Zavarivanje i zavarene konstrukcije
DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd., 59(2), 61-67.
https://doi.org/10.5937/zzk1402061B

Bajić N, Rakin M, Veljić D, Mrdak M, Stojadinović S, Pekez J. Optimizing the content of nickel in flux-cored wire intended for welding micro-alloyed steels. in Zavarivanje i zavarene konstrukcije. 2014;59(2):61-67.
doi:10.5937/zzk1402061B .

Bajić, Nikola, Rakin, Marko, Veljić, Darko, Mrdak, Mihailo, Stojadinović, Slobodan, Pekez, Jasmina, "Optimizing the content of nickel in flux-cored wire intended for welding micro-alloyed steels" in Zavarivanje i zavarene konstrukcije, 59, no. 2 (2014):61-67,
https://doi.org/10.5937/zzk1402061B . .