TY  - CONF
AU  - Mihajlović, Dragana R.
AU  - Rakin, Marko P.
AU  - Međo, Bojan I.
AU  - Đokić, Veljko R.
PY  - 2024
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7382
PB  - Vancouver : Peers Alley Media
C3  - 6th edition of Advanced Materials Science World Congress, Adv. Materials Science 2024, March 21-22, 2024
T1  - Microstructure, mechanical and corrosion properties of anodized ultrafine-grained titanium based materials for medical application
EP  - 40
SP  - 39
UR  - https://hdl.handle.net/21.15107/rcub_technorep_7382
ER  - 

@conference{
author = "Mihajlović, Dragana R. and Rakin, Marko P. and Međo, Bojan I. and Đokić, Veljko R.",
year = "2024",
publisher = "Vancouver : Peers Alley Media",
journal = "6th edition of Advanced Materials Science World Congress, Adv. Materials Science 2024, March 21-22, 2024",
title = "Microstructure, mechanical and corrosion properties of anodized ultrafine-grained titanium based materials for medical application",
pages = "40-39",
url = "https://hdl.handle.net/21.15107/rcub_technorep_7382"
}

Mihajlović, D. R., Rakin, M. P., Međo, B. I.,& Đokić, V. R.. (2024). Microstructure, mechanical and corrosion properties of anodized ultrafine-grained titanium based materials for medical application. in 6th edition of Advanced Materials Science World Congress, Adv. Materials Science 2024, March 21-22, 2024
Vancouver : Peers Alley Media., 39-40.
https://hdl.handle.net/21.15107/rcub_technorep_7382

Mihajlović DR, Rakin MP, Međo BI, Đokić VR. Microstructure, mechanical and corrosion properties of anodized ultrafine-grained titanium based materials for medical application. in 6th edition of Advanced Materials Science World Congress, Adv. Materials Science 2024, March 21-22, 2024. 2024;:39-40.
https://hdl.handle.net/21.15107/rcub_technorep_7382 .

Mihajlović, Dragana R., Rakin, Marko P., Međo, Bojan I., Đokić, Veljko R., "Microstructure, mechanical and corrosion properties of anodized ultrafine-grained titanium based materials for medical application" in 6th edition of Advanced Materials Science World Congress, Adv. Materials Science 2024, March 21-22, 2024 (2024):39-40,
https://hdl.handle.net/21.15107/rcub_technorep_7382 .

TY  - CHAP
AU  - Mihajlović, Dragana
AU  - Rakin, Marko
AU  - Hohenwarter, Anton
AU  - Veljović, Đorđe
AU  - Kojić, Vesna
AU  - Đokić, Veljko
PY  - 2024
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7147
AB  - Primary implant stability after implantation is in relation with its good mechanical contact with the touching tissue. Adequate integration of the implant with the bone tissue is necessary to provide safety and efficiency of the implant over its life. Generally, two surface properties are the most important facts for tissue response to the implant: the surface topography and chemical composition. Compared to a smooth implant surface, a controlled rough surface provides more surface area for integration with the surrounding tissues and allows successful implant ingrowth into the tissues. It was found that the nanostructured modification of the titanium surface on the level of nano-sized pores influences the adhesion, spreading and growing of osteoblastic cells. There are many methods for nanostructure modification of biomedical alloy surfaces, but one of the common techniques is electrochemical anodization (anodic oxidation). Electrochemical anodization is a method that leads to the creation of a nanotubular oxide film on the material surface. The advantage of anodic oxidation is the possibility of controlling the nanostructured morphology of the surface and dimensions of nanotubes, such as diameter, length, wall thickness and shape of nanotubes through variation of the solution, pH value, potential or duration of anodic oxidation. 
Surface modification of Ti-13Nb-13Zr alloy in a coarse-grained (as received) and ultrafine-grained state induced by high pressure torsion was conducted using an electrochemical anodization process in a 1 M H3PO4 + NaF electrolyte, for 30, 60, 90 and 120 minutes. Scanning electron microscopy (SEM) was used to analyze the morphology, while atomic force microscopy (AFM) was used to characterize the topography of the modified surface. The results showed that a homogenous nanotubular oxide film consisting of nanotubes could be obtained using the electrochemical anodization treatment, while the roughness of the nanostructured surface increased compared to the bare surface. The aim of the studies given in this chapter is to examine the morphology of the nanostructured surface and estimate in vitro biocompatibility of the above-mentioned titanium alloy after the creation of the nanotubular oxide film. In vitro examinations were performed on mouse fibroblast (L929) and human fibroblast (MRC-5) cell lines. The results showed that the nanotubular oxide film obtained on the coarse-grained Ti-13Nb-13Zr alloy (CG TNZ) and the ultrafine-grained Ti-13Nb-13Zr alloy (UFG TNZ) increased the fractions of surviving cells compared to their counterpart alloy, while the cells had better spreading and adhesion on the nanostructured and bare surfaces of the UFG titanium alloy.
PB  - Hoboken : John Wiley & Sons
PB  - Beverly : Scrivener Publishing LLC
T2  - Mechanical Engineering in Biomedical Application: Bio-3D Printing, Biofluid Mechanics, Implant Design, Biomaterials, Computational Biomechanics, Tissue Mechanics
T1  - The Effect of the Nanostructured Surface Modification on the Morphology and Biocompatibility of Ultrafine-Grained Titanium Alloy for Medical Application
EP  - 150
SP  - 121
DO  - 10.1002/9781394175109.ch5
UR  - https://hdl.handle.net/21.15107/rcub_technorep_7147
ER  - 

@inbook{
author = "Mihajlović, Dragana and Rakin, Marko and Hohenwarter, Anton and Veljović, Đorđe and Kojić, Vesna and Đokić, Veljko",
year = "2024",
abstract = "Primary implant stability after implantation is in relation with its good mechanical contact with the touching tissue. Adequate integration of the implant with the bone tissue is necessary to provide safety and efficiency of the implant over its life. Generally, two surface properties are the most important facts for tissue response to the implant: the surface topography and chemical composition. Compared to a smooth implant surface, a controlled rough surface provides more surface area for integration with the surrounding tissues and allows successful implant ingrowth into the tissues. It was found that the nanostructured modification of the titanium surface on the level of nano-sized pores influences the adhesion, spreading and growing of osteoblastic cells. There are many methods for nanostructure modification of biomedical alloy surfaces, but one of the common techniques is electrochemical anodization (anodic oxidation). Electrochemical anodization is a method that leads to the creation of a nanotubular oxide film on the material surface. The advantage of anodic oxidation is the possibility of controlling the nanostructured morphology of the surface and dimensions of nanotubes, such as diameter, length, wall thickness and shape of nanotubes through variation of the solution, pH value, potential or duration of anodic oxidation. 
Surface modification of Ti-13Nb-13Zr alloy in a coarse-grained (as received) and ultrafine-grained state induced by high pressure torsion was conducted using an electrochemical anodization process in a 1 M H3PO4 + NaF electrolyte, for 30, 60, 90 and 120 minutes. Scanning electron microscopy (SEM) was used to analyze the morphology, while atomic force microscopy (AFM) was used to characterize the topography of the modified surface. The results showed that a homogenous nanotubular oxide film consisting of nanotubes could be obtained using the electrochemical anodization treatment, while the roughness of the nanostructured surface increased compared to the bare surface. The aim of the studies given in this chapter is to examine the morphology of the nanostructured surface and estimate in vitro biocompatibility of the above-mentioned titanium alloy after the creation of the nanotubular oxide film. In vitro examinations were performed on mouse fibroblast (L929) and human fibroblast (MRC-5) cell lines. The results showed that the nanotubular oxide film obtained on the coarse-grained Ti-13Nb-13Zr alloy (CG TNZ) and the ultrafine-grained Ti-13Nb-13Zr alloy (UFG TNZ) increased the fractions of surviving cells compared to their counterpart alloy, while the cells had better spreading and adhesion on the nanostructured and bare surfaces of the UFG titanium alloy.",
publisher = "Hoboken : John Wiley & Sons, Beverly : Scrivener Publishing LLC",
journal = "Mechanical Engineering in Biomedical Application: Bio-3D Printing, Biofluid Mechanics, Implant Design, Biomaterials, Computational Biomechanics, Tissue Mechanics",
booktitle = "The Effect of the Nanostructured Surface Modification on the Morphology and Biocompatibility of Ultrafine-Grained Titanium Alloy for Medical Application",
pages = "150-121",
doi = "10.1002/9781394175109.ch5",
url = "https://hdl.handle.net/21.15107/rcub_technorep_7147"
}

Mihajlović, D., Rakin, M., Hohenwarter, A., Veljović, Đ., Kojić, V.,& Đokić, V.. (2024). The Effect of the Nanostructured Surface Modification on the Morphology and Biocompatibility of Ultrafine-Grained Titanium Alloy for Medical Application. in Mechanical Engineering in Biomedical Application: Bio-3D Printing, Biofluid Mechanics, Implant Design, Biomaterials, Computational Biomechanics, Tissue Mechanics
Hoboken : John Wiley & Sons., 121-150.
https://doi.org/10.1002/9781394175109.ch5
https://hdl.handle.net/21.15107/rcub_technorep_7147

Mihajlović D, Rakin M, Hohenwarter A, Veljović Đ, Kojić V, Đokić V. The Effect of the Nanostructured Surface Modification on the Morphology and Biocompatibility of Ultrafine-Grained Titanium Alloy for Medical Application. in Mechanical Engineering in Biomedical Application: Bio-3D Printing, Biofluid Mechanics, Implant Design, Biomaterials, Computational Biomechanics, Tissue Mechanics. 2024;:121-150.
doi:10.1002/9781394175109.ch5
https://hdl.handle.net/21.15107/rcub_technorep_7147 .

Mihajlović, Dragana, Rakin, Marko, Hohenwarter, Anton, Veljović, Đorđe, Kojić, Vesna, Đokić, Veljko, "The Effect of the Nanostructured Surface Modification on the Morphology and Biocompatibility of Ultrafine-Grained Titanium Alloy for Medical Application" in Mechanical Engineering in Biomedical Application: Bio-3D Printing, Biofluid Mechanics, Implant Design, Biomaterials, Computational Biomechanics, Tissue Mechanics (2024):121-150,
https://doi.org/10.1002/9781394175109.ch5 .,
https://hdl.handle.net/21.15107/rcub_technorep_7147 .

TY  - CONF
AU  - Rakin, Marko
AU  - Mihajlović, Dragana
AU  - Međo, Bojan
AU  - Đokić, Veljko
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6294
AB  - The Ti-13Nb-13Zr alloy made by conventional methods (coarse-grained, CG) was examined, as well as the alloy and commercially pure titanium (cpTi) after the high pressure torsion (HPT) process (ultrafine-grained, UFG) performed at room temperature. All materials were subjected to nanostructured surface modification. Nanostructured surface modification was done in 1M H3PO4 + 0.5 wt. % NaF electrolyte during 60 and 90 minutes, for the desired potential of 25V with a scan rate of 100 mVs-1. As the result of the nanostructured surface modification nanotubular titanium based oxide layer was obtained.
Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the homogeneity of nanotubular titanium based oxide layer and dimensions of the formed nanotubes. In order to define the chemical structure of oxide layer, energy dispersive spectroscopy (EDS) was used. The obtained results indicate that the duration of the nanostructured surface modification significantly affects on the homogeneity of the nanotubular titanium based oxide layer morphology, as well as on the dimensions of the nanotubes (diameter and wall thickness of the nanotubes). Also, the effect of the HPT process on the homogeneity and thickness of the nanotubular oxide layer (length of the nanotubes) are shown and discussed.
The mechanical behavior of nanotubular titanium based oxide layer was examined by nanoindentation test. The control of nanoindentation test was done by total displacement. The displacements were 2000 nm for non-modified surface and 10% of the thickness of nanotubular titanium based oxide layer for modified surface. The test was performed on a nanoindenter using as an indenter the Berkovich-type diamond tip. As results, loading-displacement curves and the mean value of ten measurements of the surface modulus of elasticity and nanohardness were obtained. Also, in order to characterize deformation of the oxide layer after nanoindentation SEM was done. Having in mind that nanotubular oxide thin layer can affect tensile properties of metallic materials, tensile testing was performed.
PB  - InovSciTech No. 302, Uttarahalli, Bangalore-560061, India
C3  - 6th Global Webinar on Materials Science & Engineering (GWMSE-2023), The International Research Conference
T1  - Structural and mechanical behavior of titanium based oxide thin layer for biomedical application
EP  - 15
SP  - 14
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6294
ER  - 

@conference{
author = "Rakin, Marko and Mihajlović, Dragana and Međo, Bojan and Đokić, Veljko",
year = "2023",
abstract = "The Ti-13Nb-13Zr alloy made by conventional methods (coarse-grained, CG) was examined, as well as the alloy and commercially pure titanium (cpTi) after the high pressure torsion (HPT) process (ultrafine-grained, UFG) performed at room temperature. All materials were subjected to nanostructured surface modification. Nanostructured surface modification was done in 1M H3PO4 + 0.5 wt. % NaF electrolyte during 60 and 90 minutes, for the desired potential of 25V with a scan rate of 100 mVs-1. As the result of the nanostructured surface modification nanotubular titanium based oxide layer was obtained.
Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the homogeneity of nanotubular titanium based oxide layer and dimensions of the formed nanotubes. In order to define the chemical structure of oxide layer, energy dispersive spectroscopy (EDS) was used. The obtained results indicate that the duration of the nanostructured surface modification significantly affects on the homogeneity of the nanotubular titanium based oxide layer morphology, as well as on the dimensions of the nanotubes (diameter and wall thickness of the nanotubes). Also, the effect of the HPT process on the homogeneity and thickness of the nanotubular oxide layer (length of the nanotubes) are shown and discussed.
The mechanical behavior of nanotubular titanium based oxide layer was examined by nanoindentation test. The control of nanoindentation test was done by total displacement. The displacements were 2000 nm for non-modified surface and 10% of the thickness of nanotubular titanium based oxide layer for modified surface. The test was performed on a nanoindenter using as an indenter the Berkovich-type diamond tip. As results, loading-displacement curves and the mean value of ten measurements of the surface modulus of elasticity and nanohardness were obtained. Also, in order to characterize deformation of the oxide layer after nanoindentation SEM was done. Having in mind that nanotubular oxide thin layer can affect tensile properties of metallic materials, tensile testing was performed.",
publisher = "InovSciTech No. 302, Uttarahalli, Bangalore-560061, India",
journal = "6th Global Webinar on Materials Science & Engineering (GWMSE-2023), The International Research Conference",
title = "Structural and mechanical behavior of titanium based oxide thin layer for biomedical application",
pages = "15-14",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6294"
}

Rakin, M., Mihajlović, D., Međo, B.,& Đokić, V.. (2023). Structural and mechanical behavior of titanium based oxide thin layer for biomedical application. in 6th Global Webinar on Materials Science & Engineering (GWMSE-2023), The International Research Conference
InovSciTech No. 302, Uttarahalli, Bangalore-560061, India., 14-15.
https://hdl.handle.net/21.15107/rcub_technorep_6294

Rakin M, Mihajlović D, Međo B, Đokić V. Structural and mechanical behavior of titanium based oxide thin layer for biomedical application. in 6th Global Webinar on Materials Science & Engineering (GWMSE-2023), The International Research Conference. 2023;:14-15.
https://hdl.handle.net/21.15107/rcub_technorep_6294 .

Rakin, Marko, Mihajlović, Dragana, Međo, Bojan, Đokić, Veljko, "Structural and mechanical behavior of titanium based oxide thin layer for biomedical application" in 6th Global Webinar on Materials Science & Engineering (GWMSE-2023), The International Research Conference (2023):14-15,
https://hdl.handle.net/21.15107/rcub_technorep_6294 .

TY  - CONF
AU  - Mihajlović, Dragana
AU  - Rakin, Marko
AU  - Veljović, Đorđe
AU  - Međo, Bojan
AU  - Đokić, Veljko
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7011
AB  - The coarse-grained (CG) and ultrafine-grained (UFG) Ti-13Nb-13Zr alloy (TNZ) were used as tested materials in this
study. UFG alloy was obtained using a high-pressure torsion process (HPT) at room temperature, with 5 rotations, and
with 4.1 GPa pressure. After that, the surface was modified using electrochemical anodization in the 1M H3PO4 + NaF
electrolyte, for 60 and 90 minutes.
Scanning electron microscopy (SEM) was used to characterize the morphology of the modified surface after
electrochemical anodization. In order to determine whether the electrochemical anodization leads to obtaining the
surface modulus of elasticity values close to the values characteristic of the human bones, a nanoindentation test was
done. The nanoindentation test was performed on the device called nanoindenter G200, Agilent Technologies, where
a diamond tip of the Berkovich type shaped as a three-sided pyramid was used as an indenter. Control of
the nanoindentation test was done by nanoindentation depth, where for non-anodized materials a depth of 2000 nm was
used, while for anodized materials a minimum value of 10% of the thickness of the formed nanostructured oxide layer
was used. Biocompatibility of the tested titanium alloy was estimated by the tetrazolium salt colorimetric test
(MTT test) using mouse fibroblasts (L-929) and human lung fibroblasts (MRC-5). The cell adhesion on the alloy
surface was analyzed using SEM.
Electrochemical anodization has led to the formation of the nanostructured oxide layer on the titanium alloy surface.
The obtained results show the existence of the influence of anodizing time on the nanostructured oxide layer
morphology. Characterization of the titanium alloy surface using nanoindentation showed a decrease in the values
of modulus of elasticity for an alloy with a nanostructured oxide layer, which is close to the values of bone tissue in
the human body. The results of the MTT test showed that the titanium alloys before and after electrochemical
anodization were not cytotoxic. After electrochemical anodization, a uniform nanostructured surface, with nanotubes,
was formed which led to better cell viability and adhesion of L-929 and MRC-5 cells in contact with the test alloys than
of cells in contact with the control material.
PB  - Belgrade : Association of Metallurgical Engineers of Serbia (AMES)
C3  - Book of Abstracts / 5th Metallurgical & Materials Engineering Congress of SouthEast Europe MME SEE Congress 2023, Trebinje, Bosnia and Herzegovina 7-10th June 2023
T1  - Advancement of biocompatibility and mechanical surface characteristics of the Ti-13Nb-13Zr alloy using electrochemical anodization
SP  - 56
UR  - https://hdl.handle.net/21.15107/rcub_technorep_7011
ER  - 

@conference{
author = "Mihajlović, Dragana and Rakin, Marko and Veljović, Đorđe and Međo, Bojan and Đokić, Veljko",
year = "2023",
abstract = "The coarse-grained (CG) and ultrafine-grained (UFG) Ti-13Nb-13Zr alloy (TNZ) were used as tested materials in this
study. UFG alloy was obtained using a high-pressure torsion process (HPT) at room temperature, with 5 rotations, and
with 4.1 GPa pressure. After that, the surface was modified using electrochemical anodization in the 1M H3PO4 + NaF
electrolyte, for 60 and 90 minutes.
Scanning electron microscopy (SEM) was used to characterize the morphology of the modified surface after
electrochemical anodization. In order to determine whether the electrochemical anodization leads to obtaining the
surface modulus of elasticity values close to the values characteristic of the human bones, a nanoindentation test was
done. The nanoindentation test was performed on the device called nanoindenter G200, Agilent Technologies, where
a diamond tip of the Berkovich type shaped as a three-sided pyramid was used as an indenter. Control of
the nanoindentation test was done by nanoindentation depth, where for non-anodized materials a depth of 2000 nm was
used, while for anodized materials a minimum value of 10% of the thickness of the formed nanostructured oxide layer
was used. Biocompatibility of the tested titanium alloy was estimated by the tetrazolium salt colorimetric test
(MTT test) using mouse fibroblasts (L-929) and human lung fibroblasts (MRC-5). The cell adhesion on the alloy
surface was analyzed using SEM.
Electrochemical anodization has led to the formation of the nanostructured oxide layer on the titanium alloy surface.
The obtained results show the existence of the influence of anodizing time on the nanostructured oxide layer
morphology. Characterization of the titanium alloy surface using nanoindentation showed a decrease in the values
of modulus of elasticity for an alloy with a nanostructured oxide layer, which is close to the values of bone tissue in
the human body. The results of the MTT test showed that the titanium alloys before and after electrochemical
anodization were not cytotoxic. After electrochemical anodization, a uniform nanostructured surface, with nanotubes,
was formed which led to better cell viability and adhesion of L-929 and MRC-5 cells in contact with the test alloys than
of cells in contact with the control material.",
publisher = "Belgrade : Association of Metallurgical Engineers of Serbia (AMES)",
journal = "Book of Abstracts / 5th Metallurgical & Materials Engineering Congress of SouthEast Europe MME SEE Congress 2023, Trebinje, Bosnia and Herzegovina 7-10th June 2023",
title = "Advancement of biocompatibility and mechanical surface characteristics of the Ti-13Nb-13Zr alloy using electrochemical anodization",
pages = "56",
url = "https://hdl.handle.net/21.15107/rcub_technorep_7011"
}

Mihajlović, D., Rakin, M., Veljović, Đ., Međo, B.,& Đokić, V.. (2023). Advancement of biocompatibility and mechanical surface characteristics of the Ti-13Nb-13Zr alloy using electrochemical anodization. in Book of Abstracts / 5th Metallurgical & Materials Engineering Congress of SouthEast Europe MME SEE Congress 2023, Trebinje, Bosnia and Herzegovina 7-10th June 2023
Belgrade : Association of Metallurgical Engineers of Serbia (AMES)., 56.
https://hdl.handle.net/21.15107/rcub_technorep_7011

Mihajlović D, Rakin M, Veljović Đ, Međo B, Đokić V. Advancement of biocompatibility and mechanical surface characteristics of the Ti-13Nb-13Zr alloy using electrochemical anodization. in Book of Abstracts / 5th Metallurgical & Materials Engineering Congress of SouthEast Europe MME SEE Congress 2023, Trebinje, Bosnia and Herzegovina 7-10th June 2023. 2023;:56.
https://hdl.handle.net/21.15107/rcub_technorep_7011 .

Mihajlović, Dragana, Rakin, Marko, Veljović, Đorđe, Međo, Bojan, Đokić, Veljko, "Advancement of biocompatibility and mechanical surface characteristics of the Ti-13Nb-13Zr alloy using electrochemical anodization" in Book of Abstracts / 5th Metallurgical & Materials Engineering Congress of SouthEast Europe MME SEE Congress 2023, Trebinje, Bosnia and Herzegovina 7-10th June 2023 (2023):56,
https://hdl.handle.net/21.15107/rcub_technorep_7011 .

TY  - JOUR
AU  - Mihajlović, Dragana
AU  - Rakin, Marko
AU  - Bajat, Jelena
AU  - Đokić, Veljko
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6975
AB  - Nanostructured surface modification was performed on the ultrafine-grained commercially
pure titanium (UFG cpTi) using electrochemical anodization. The characterization of the
morphology of the nanostructured surface obtained during different times of electrochemical
anodization was done using scanning electron microscopy (SEM). The corrosion resistance
of the materials was examined using the potentiodynamic method and electrochemical
impedance spectroscopy (EIS), during which the electrochemical characteristics of oxide
layers and the evaluation of the corrosion resistance of the mentioned materials were
determined. These materials were exposed to a solution simulating conditions in the human
body (artificial saliva solution) with a pH of 5.5 at a temperature of 37 ºC. The obtained results
indicate the extensive influence of time, as a parameter of electrochemical anodization on the
surface morphology. The electrochemical anodization of 60 minutes can lead to the creation
of the nanotubular oxide layer on the UFG cpTi surface, while the electrochemical anodization
of 30 and 90 minutes did not lead to the creation of the nanotubular oxide layer, but it is up
to the surface modification of UFG cpTi. Electrochemical tests showed a slight increase in the
corrosion resistance in a solution of artificial saliva after electrochemical anodization. Also,
the electrochemical impedance spectra for anodized and non-anodized UFG cpTi show the
characteristics of corrosion resistance, but the anodized UFG cpTi has better resistance to the
oxide layer. It can be concluded that anodized UFG cpTi has better corrosion stability, but
both non-anodized and anodized UFG cpTi show exceptional corrosion stability in simulated
conditions of the human body, which makes them equally suitable for use in medicine.
PB  - Association of Metallurgical Engineers of Serbia
T2  - Metallurgical and Materials Data. Advanced Functional Materials
T1  - Corrosion Stability of the Anodized Ultrafine-Grained Titanium in the Human Body Solution
EP  - 11
IS  - 1
SP  - 7
VL  - 1
DO  - 10.56801/MMD3
ER  - 

@article{
author = "Mihajlović, Dragana and Rakin, Marko and Bajat, Jelena and Đokić, Veljko",
year = "2023",
abstract = "Nanostructured surface modification was performed on the ultrafine-grained commercially
pure titanium (UFG cpTi) using electrochemical anodization. The characterization of the
morphology of the nanostructured surface obtained during different times of electrochemical
anodization was done using scanning electron microscopy (SEM). The corrosion resistance
of the materials was examined using the potentiodynamic method and electrochemical
impedance spectroscopy (EIS), during which the electrochemical characteristics of oxide
layers and the evaluation of the corrosion resistance of the mentioned materials were
determined. These materials were exposed to a solution simulating conditions in the human
body (artificial saliva solution) with a pH of 5.5 at a temperature of 37 ºC. The obtained results
indicate the extensive influence of time, as a parameter of electrochemical anodization on the
surface morphology. The electrochemical anodization of 60 minutes can lead to the creation
of the nanotubular oxide layer on the UFG cpTi surface, while the electrochemical anodization
of 30 and 90 minutes did not lead to the creation of the nanotubular oxide layer, but it is up
to the surface modification of UFG cpTi. Electrochemical tests showed a slight increase in the
corrosion resistance in a solution of artificial saliva after electrochemical anodization. Also,
the electrochemical impedance spectra for anodized and non-anodized UFG cpTi show the
characteristics of corrosion resistance, but the anodized UFG cpTi has better resistance to the
oxide layer. It can be concluded that anodized UFG cpTi has better corrosion stability, but
both non-anodized and anodized UFG cpTi show exceptional corrosion stability in simulated
conditions of the human body, which makes them equally suitable for use in medicine.",
publisher = "Association of Metallurgical Engineers of Serbia",
journal = "Metallurgical and Materials Data. Advanced Functional Materials",
title = "Corrosion Stability of the Anodized Ultrafine-Grained Titanium in the Human Body Solution",
pages = "11-7",
number = "1",
volume = "1",
doi = "10.56801/MMD3"
}

Mihajlović, D., Rakin, M., Bajat, J.,& Đokić, V.. (2023). Corrosion Stability of the Anodized Ultrafine-Grained Titanium in the Human Body Solution. in Metallurgical and Materials Data. Advanced Functional Materials
Association of Metallurgical Engineers of Serbia., 1(1), 7-11.
https://doi.org/10.56801/MMD3

Mihajlović D, Rakin M, Bajat J, Đokić V. Corrosion Stability of the Anodized Ultrafine-Grained Titanium in the Human Body Solution. in Metallurgical and Materials Data. Advanced Functional Materials. 2023;1(1):7-11.
doi:10.56801/MMD3 .

Mihajlović, Dragana, Rakin, Marko, Bajat, Jelena, Đokić, Veljko, "Corrosion Stability of the Anodized Ultrafine-Grained Titanium in the Human Body Solution" in Metallurgical and Materials Data. Advanced Functional Materials, 1, no. 1 (2023):7-11,
https://doi.org/10.56801/MMD3 . .

TY  - CONF
AU  - Mihajlović, Dragana R.
AU  - Rakin, Marko P.
AU  - Bajat, Jelena B.
AU  - Međo, Bojan I.
AU  - Đokić, Veljko R.
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6974
AB  - Titanium-based nanotubelayer was formed through the electrochemical anodization technique on
coarse-grained and ultrafine-grained Ti-13Nb-13Zr (wt.%) alloy, in 1M H3PO4 + NaF electrolyte
for 90 minutes. The nanotube layer morphology was analyzed using the scanning electron
microscopy (SEM) and the X-ray diffraction (XRD). The electrochemical impedance spectroscopy (EIS) technique was used to determine the corrosion resistance of the alloy before and after
electrochemical anodization. These materials were exposed to a solution simulating conditions in
the human body (Ringer'
s solution) with pH of 5.5 at a temperature of 37 ºC. In order to investigate
the titanium-based nanotube layer adhesion on alloy surface a scratch test was done. The scratch
test was performedon nanoindenter G200, Agilent Technologies, using an indenter Berkovichtype diamond tip with applying an increasing load up to 40 mN. It was established that electrochemical anodization led to the formation of the nanotube oxide layer on the surface of titaniumbased materials. Influence of the ultrafine-grained material structure on the homogeneity of the
nanotube layer obtained by electrochemical anodization has been noticed. Both coarse-grained
and ultrafine-grained alloy showed excellent corrosion resistance in Ringer’s solution. Moreover,
electrochemical anodization led to a decrease or an increase of the corrosion resistance of these
materials, depending on the nanotube layer morphology. The scratch test showed that plastic
deformation was present in the nanotube layer. The scratch resistance for the nanotube layer
failure was on the higher load, pointing to the good adhesion for the titanium-based nanotube layer
formed using electrochemical anodization.
PB  - Belgrade : Materials Research Society of Serbia
C3  - Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023
T1  - Corrosion and scratch resistance of the nanotube layer formed on the titanium-based materials
SP  - 171
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6974
ER  - 

@conference{
author = "Mihajlović, Dragana R. and Rakin, Marko P. and Bajat, Jelena B. and Međo, Bojan I. and Đokić, Veljko R.",
year = "2023",
abstract = "Titanium-based nanotubelayer was formed through the electrochemical anodization technique on
coarse-grained and ultrafine-grained Ti-13Nb-13Zr (wt.%) alloy, in 1M H3PO4 + NaF electrolyte
for 90 minutes. The nanotube layer morphology was analyzed using the scanning electron
microscopy (SEM) and the X-ray diffraction (XRD). The electrochemical impedance spectroscopy (EIS) technique was used to determine the corrosion resistance of the alloy before and after
electrochemical anodization. These materials were exposed to a solution simulating conditions in
the human body (Ringer'
s solution) with pH of 5.5 at a temperature of 37 ºC. In order to investigate
the titanium-based nanotube layer adhesion on alloy surface a scratch test was done. The scratch
test was performedon nanoindenter G200, Agilent Technologies, using an indenter Berkovichtype diamond tip with applying an increasing load up to 40 mN. It was established that electrochemical anodization led to the formation of the nanotube oxide layer on the surface of titaniumbased materials. Influence of the ultrafine-grained material structure on the homogeneity of the
nanotube layer obtained by electrochemical anodization has been noticed. Both coarse-grained
and ultrafine-grained alloy showed excellent corrosion resistance in Ringer’s solution. Moreover,
electrochemical anodization led to a decrease or an increase of the corrosion resistance of these
materials, depending on the nanotube layer morphology. The scratch test showed that plastic
deformation was present in the nanotube layer. The scratch resistance for the nanotube layer
failure was on the higher load, pointing to the good adhesion for the titanium-based nanotube layer
formed using electrochemical anodization.",
publisher = "Belgrade : Materials Research Society of Serbia",
journal = "Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023",
title = "Corrosion and scratch resistance of the nanotube layer formed on the titanium-based materials",
pages = "171",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6974"
}

Mihajlović, D. R., Rakin, M. P., Bajat, J. B., Međo, B. I.,& Đokić, V. R.. (2023). Corrosion and scratch resistance of the nanotube layer formed on the titanium-based materials. in Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023
Belgrade : Materials Research Society of Serbia., 171.
https://hdl.handle.net/21.15107/rcub_technorep_6974

Mihajlović DR, Rakin MP, Bajat JB, Međo BI, Đokić VR. Corrosion and scratch resistance of the nanotube layer formed on the titanium-based materials. in Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023. 2023;:171.
https://hdl.handle.net/21.15107/rcub_technorep_6974 .

Mihajlović, Dragana R., Rakin, Marko P., Bajat, Jelena B., Međo, Bojan I., Đokić, Veljko R., "Corrosion and scratch resistance of the nanotube layer formed on the titanium-based materials" in Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023 (2023):171,
https://hdl.handle.net/21.15107/rcub_technorep_6974 .

TY  - CONF
AU  - Mihajlović, Dragana
AU  - Međo, Bojan
AU  - Đokić, Veljko
AU  - Bajat, Jelena
AU  - Rakin, Marko
AU  - Putić, Slaviša
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7172
AB  - Intenzivno plastično deformisanje (IPD, eng. Severe Plastic Deformation, SPD)  jesu različiti savremeni postupci čiji je osnovni cilj dobijanje sitnozrne strukture (eng. ultrafine-grained, UFG) metalnih materijala. Sitnozrni metalni materijali najčešće pokazuju poboljšana mehanička svojstva u odnosu na metalne materijale dobijene konvencionalnim postupcima izrade, dok je koroziona otpornost ovih materijala još uvek nedovoljno ispitana. Jedna od metoda intenzivnog plastičnog deformisanja je i metoda uvijanja pod visokim pritiskom (UVP, eng. High Pressure Torsion, HPT). U cilju ispitivanja uticaja nanostrukturne modifikacije površine na svojstva sitnozrnog komercijalnog čistog titana (korozionu postojanost, površinski modul elastičnosti i tvrdoću) u radu je urađena elektrohemijska anodizacija. Karakterizacija površinske modifikovane strukture kod sitnozrnog komercijalnog čistog titana urađena je primenom skenirajuće elektronske mikroskopije (eng. Scanning Electron Microscopy, SEM). Homogenost materijala nakon UVP postupka procenjen je merenjem mikrotvrdoće duž prečnika uzoraka primenom metode po Vikersu (eng. Vickers). Otpornost prema koroziji sitnozrnog komercijalnog čistog titana pre i posle elektrohemijske andizacije ispitana je primenom potenciodinamičke metode, pri čemu je pokazano povećanje korozione otpornosti u simuliranom rastvoru ljudskog organizma. Karakterizacija površine sitnozrnog komercijalnog čistog titana primenom nanoindentacije pokazala je smanjenje vrednosti površinskog modula elastičnosti i tvrdoće kod materijala sa nanostrukturnim oksidnim slojem, koje su bliže vrednostima koštanog tkiva u ljudskom organizmu.
AB  - Severe Plastic Deformation (SPD) are modern procedures whose main goal is to obtain an
ultrafine-grained structure of metallic materials. Ultrafine-grained metallic materials show
improved mechanical properties compared to metallic materials obtained by conventional
manufacturing methods, while the corrosion resistance of these materials is still insufficiently
tested. One of the methods of Severe Plastic Deformation is the method of High Pressure
Torsion (HPT). In order to examine the influence of nanostructural surface modification on
the properties of ultrafine-grained commercially pure titanium (corrosion resistance, surface
modulus of elasticity and hardness), electrochemical anodization was performed. The
characterization of the surface modified structure of ultrafine-grained commercially pure
titanium was performed using Scanning Electron Microscopy (SEM). The homogeneity of
the material after the HPT procedure was assessed by measuring the microhardness along the
diameter of the samples using the Vickers method. Corrosion resistance of ultrafine-grained
commercially pure titanium before and after electrochemical andization was tested using the
potentiodynamic method, where an increase corrosion resistance in a simulated solution of
the human organism was demonstrated. The characterization of the surface of the comercially
pure titanium using nanoindentation showed a decrease in the values of the surface modulus
of elasticity and hardness for titanium with a nanostructured oxide layer, which are closer to
the values of bone tissue in the human body.
PB  - Požarevac : Savez društava inženjera i tehničara grada Požarevca
PB  - Požarevac : Društvo hemičara, tehnologa i metalurga
C3  - Zbornik radova / Savetovanje "Novi materijali i mogućnosti njihove primene", Požarevac, 2023 godine
T1  - Uticaj nanostrukturne modifikacije površine na svojstva komercijalno čistog titana za primenu u medicini
T1  - The influence of nanostructure surface modification on the properties of commercially pure titanium for application in medicine
EP  - 60
SP  - 51
UR  - https://hdl.handle.net/21.15107/rcub_technorep_7172
ER  - 

@conference{
author = "Mihajlović, Dragana and Međo, Bojan and Đokić, Veljko and Bajat, Jelena and Rakin, Marko and Putić, Slaviša",
year = "2023",
abstract = "Intenzivno plastično deformisanje (IPD, eng. Severe Plastic Deformation, SPD)  jesu različiti savremeni postupci čiji je osnovni cilj dobijanje sitnozrne strukture (eng. ultrafine-grained, UFG) metalnih materijala. Sitnozrni metalni materijali najčešće pokazuju poboljšana mehanička svojstva u odnosu na metalne materijale dobijene konvencionalnim postupcima izrade, dok je koroziona otpornost ovih materijala još uvek nedovoljno ispitana. Jedna od metoda intenzivnog plastičnog deformisanja je i metoda uvijanja pod visokim pritiskom (UVP, eng. High Pressure Torsion, HPT). U cilju ispitivanja uticaja nanostrukturne modifikacije površine na svojstva sitnozrnog komercijalnog čistog titana (korozionu postojanost, površinski modul elastičnosti i tvrdoću) u radu je urađena elektrohemijska anodizacija. Karakterizacija površinske modifikovane strukture kod sitnozrnog komercijalnog čistog titana urađena je primenom skenirajuće elektronske mikroskopije (eng. Scanning Electron Microscopy, SEM). Homogenost materijala nakon UVP postupka procenjen je merenjem mikrotvrdoće duž prečnika uzoraka primenom metode po Vikersu (eng. Vickers). Otpornost prema koroziji sitnozrnog komercijalnog čistog titana pre i posle elektrohemijske andizacije ispitana je primenom potenciodinamičke metode, pri čemu je pokazano povećanje korozione otpornosti u simuliranom rastvoru ljudskog organizma. Karakterizacija površine sitnozrnog komercijalnog čistog titana primenom nanoindentacije pokazala je smanjenje vrednosti površinskog modula elastičnosti i tvrdoće kod materijala sa nanostrukturnim oksidnim slojem, koje su bliže vrednostima koštanog tkiva u ljudskom organizmu., Severe Plastic Deformation (SPD) are modern procedures whose main goal is to obtain an
ultrafine-grained structure of metallic materials. Ultrafine-grained metallic materials show
improved mechanical properties compared to metallic materials obtained by conventional
manufacturing methods, while the corrosion resistance of these materials is still insufficiently
tested. One of the methods of Severe Plastic Deformation is the method of High Pressure
Torsion (HPT). In order to examine the influence of nanostructural surface modification on
the properties of ultrafine-grained commercially pure titanium (corrosion resistance, surface
modulus of elasticity and hardness), electrochemical anodization was performed. The
characterization of the surface modified structure of ultrafine-grained commercially pure
titanium was performed using Scanning Electron Microscopy (SEM). The homogeneity of
the material after the HPT procedure was assessed by measuring the microhardness along the
diameter of the samples using the Vickers method. Corrosion resistance of ultrafine-grained
commercially pure titanium before and after electrochemical andization was tested using the
potentiodynamic method, where an increase corrosion resistance in a simulated solution of
the human organism was demonstrated. The characterization of the surface of the comercially
pure titanium using nanoindentation showed a decrease in the values of the surface modulus
of elasticity and hardness for titanium with a nanostructured oxide layer, which are closer to
the values of bone tissue in the human body.",
publisher = "Požarevac : Savez društava inženjera i tehničara grada Požarevca, Požarevac : Društvo hemičara, tehnologa i metalurga",
journal = "Zbornik radova / Savetovanje "Novi materijali i mogućnosti njihove primene", Požarevac, 2023 godine",
title = "Uticaj nanostrukturne modifikacije površine na svojstva komercijalno čistog titana za primenu u medicini, The influence of nanostructure surface modification on the properties of commercially pure titanium for application in medicine",
pages = "60-51",
url = "https://hdl.handle.net/21.15107/rcub_technorep_7172"
}

Mihajlović, D., Međo, B., Đokić, V., Bajat, J., Rakin, M.,& Putić, S.. (2023). Uticaj nanostrukturne modifikacije površine na svojstva komercijalno čistog titana za primenu u medicini. in Zbornik radova / Savetovanje "Novi materijali i mogućnosti njihove primene", Požarevac, 2023 godine
Požarevac : Savez društava inženjera i tehničara grada Požarevca., 51-60.
https://hdl.handle.net/21.15107/rcub_technorep_7172

Mihajlović D, Međo B, Đokić V, Bajat J, Rakin M, Putić S. Uticaj nanostrukturne modifikacije površine na svojstva komercijalno čistog titana za primenu u medicini. in Zbornik radova / Savetovanje "Novi materijali i mogućnosti njihove primene", Požarevac, 2023 godine. 2023;:51-60.
https://hdl.handle.net/21.15107/rcub_technorep_7172 .

Mihajlović, Dragana, Međo, Bojan, Đokić, Veljko, Bajat, Jelena, Rakin, Marko, Putić, Slaviša, "Uticaj nanostrukturne modifikacije površine na svojstva komercijalno čistog titana za primenu u medicini" in Zbornik radova / Savetovanje "Novi materijali i mogućnosti njihove primene", Požarevac, 2023 godine (2023):51-60,
https://hdl.handle.net/21.15107/rcub_technorep_7172 .

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  - CONF
AU  - Barjaktarević, Dragana R.
AU  - Rakin, Marko P.
AU  - Međo, Bojan I.
AU  - Radosavljević, Zoran M.
AU  - Đokić, Veljko R.
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6018
AB  - Titanium alloys are metal materials widely used in medicine owing to their suitable characteristics such as low density, good corrosion resistance and biocompatibillity. High biocompatibility of the titanium alloy results from the creation of a spontaneous oxide layer with good adhesion and homogeneous morphology. In order to improve characteristics of the metallic materials for application in medicine, electrochemical methods that enable surface nanostructured modification are extensively used, and one of these methods is electrochemical anodization which makes it possible to obtain a nanostructured oxide layer composed of nanotubes on the surface of the metal material. The tested material was ultrafine-grained Ti-13Nb-13Zr (UFG TNZ) alloy obtained by the severe plastic deformation (SPD) processing using the high pressure torsion (HPT) process. Nanostructured oxide layer on the titanium alloy was formed by electrochemical anodization during the time period from 30 to 120 minutes. Characterization of the surface morphology obtained during different times of electrochemical anodization was done using scanning electron microscopy (SEM), while the topography and surface roughness of the titanium alloy before and after electrochemical anodization was determined using atomic force microscopy (AFM). Scratch test was used to determine the cross profile of the surface topography and critical load during scratching. Electrochemical anodization led to the formation of a nanostructured oxide layer on the surface of the titanium alloy. The obtained results indicated strong influence of the electrochemical anodization time on the oxide layer morphology - with its increase the diameter of the nanotubes increases too, while the wall thickness of nanotubes decreases. Also, electrochemical anodization led to an increase in the surface roughness.
PB  - Novi Sad : Faculty of Technology
C3  - Proceedings of the 2nd International Conference on Advanced Production and Processing ICAPP 2022, Novi Sad
T1  - THE SURFACE CHARACTERIZATION OF THE ANODIZED ULTRAFINE-GRAINED Ti-13Nb-13Zr ALLOY
EP  - 114
SP  - 105
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6018
ER  - 

@conference{
author = "Barjaktarević, Dragana R. and Rakin, Marko P. and Međo, Bojan I. and Radosavljević, Zoran M. and Đokić, Veljko R.",
year = "2023",
abstract = "Titanium alloys are metal materials widely used in medicine owing to their suitable characteristics such as low density, good corrosion resistance and biocompatibillity. High biocompatibility of the titanium alloy results from the creation of a spontaneous oxide layer with good adhesion and homogeneous morphology. In order to improve characteristics of the metallic materials for application in medicine, electrochemical methods that enable surface nanostructured modification are extensively used, and one of these methods is electrochemical anodization which makes it possible to obtain a nanostructured oxide layer composed of nanotubes on the surface of the metal material. The tested material was ultrafine-grained Ti-13Nb-13Zr (UFG TNZ) alloy obtained by the severe plastic deformation (SPD) processing using the high pressure torsion (HPT) process. Nanostructured oxide layer on the titanium alloy was formed by electrochemical anodization during the time period from 30 to 120 minutes. Characterization of the surface morphology obtained during different times of electrochemical anodization was done using scanning electron microscopy (SEM), while the topography and surface roughness of the titanium alloy before and after electrochemical anodization was determined using atomic force microscopy (AFM). Scratch test was used to determine the cross profile of the surface topography and critical load during scratching. Electrochemical anodization led to the formation of a nanostructured oxide layer on the surface of the titanium alloy. The obtained results indicated strong influence of the electrochemical anodization time on the oxide layer morphology - with its increase the diameter of the nanotubes increases too, while the wall thickness of nanotubes decreases. Also, electrochemical anodization led to an increase in the surface roughness.",
publisher = "Novi Sad : Faculty of Technology",
journal = "Proceedings of the 2nd International Conference on Advanced Production and Processing ICAPP 2022, Novi Sad",
title = "THE SURFACE CHARACTERIZATION OF THE ANODIZED ULTRAFINE-GRAINED Ti-13Nb-13Zr ALLOY",
pages = "114-105",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6018"
}

Barjaktarević, D. R., Rakin, M. P., Međo, B. I., Radosavljević, Z. M.,& Đokić, V. R.. (2023). THE SURFACE CHARACTERIZATION OF THE ANODIZED ULTRAFINE-GRAINED Ti-13Nb-13Zr ALLOY. in Proceedings of the 2nd International Conference on Advanced Production and Processing ICAPP 2022, Novi Sad
Novi Sad : Faculty of Technology., 105-114.
https://hdl.handle.net/21.15107/rcub_technorep_6018

Barjaktarević DR, Rakin MP, Međo BI, Radosavljević ZM, Đokić VR. THE SURFACE CHARACTERIZATION OF THE ANODIZED ULTRAFINE-GRAINED Ti-13Nb-13Zr ALLOY. in Proceedings of the 2nd International Conference on Advanced Production and Processing ICAPP 2022, Novi Sad. 2023;:105-114.
https://hdl.handle.net/21.15107/rcub_technorep_6018 .

Barjaktarević, Dragana R., Rakin, Marko P., Međo, Bojan I., Radosavljević, Zoran M., Đokić, Veljko R., "THE SURFACE CHARACTERIZATION OF THE ANODIZED ULTRAFINE-GRAINED Ti-13Nb-13Zr ALLOY" in Proceedings of the 2nd International Conference on Advanced Production and Processing ICAPP 2022, Novi Sad (2023):105-114,
https://hdl.handle.net/21.15107/rcub_technorep_6018 .

TY  - JOUR
AU  - Sedmak, Aleksandar
AU  - Doncheva, Elisaveta
AU  - Međo, Bojan
AU  - Rakin, Marko
AU  - Milošević, Nenad
AU  - Radu, Dorin
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6584
AB  - Crack size and undermatching effects on fracture behavior of undermatched welded joints are presented and analyzed. Experimental and numerical analysis of the fracture behavior of high-strength low-alloyed (HSLA) steel welded joints with so-called small and large crack in undermatched weld metal and the base metal was performed, as a part of more extensive research previously conducted. J integral was determined by direct measurement using special instrumentation including strain gauges and a CMOD measuring device. Numerical analysis was performed by 3D finite element method (FEM) with different tensile properties in BM and WM. Results of J-CMOD curves evaluation for SUMITEN SM 80P HSLA steel and its weld metal (WM) are presented and analyzed for small and large cracks in tensile panels. This paper is focused on some new numerical results and observations on crack tip fields and constraint effects of undermatching and crack size keeping in mind previously performed experiments on the full-scale prototype. In this way, a unique combined approach of experimental investigation on the full-scale proto-type and tensile panels, as well as numerical investigation on mismatching and crack size effects, is achieved.
PB  - MDPI
T2  - Materials
T1  - Crack Size and Undermatching Effects on Fracture Behavior of a Welded Joint
IS  - 13
SP  - 4858
VL  - 16
DO  - 10.3390/ma16134858
ER  - 

@article{
author = "Sedmak, Aleksandar and Doncheva, Elisaveta and Međo, Bojan and Rakin, Marko and Milošević, Nenad and Radu, Dorin",
year = "2023",
abstract = "Crack size and undermatching effects on fracture behavior of undermatched welded joints are presented and analyzed. Experimental and numerical analysis of the fracture behavior of high-strength low-alloyed (HSLA) steel welded joints with so-called small and large crack in undermatched weld metal and the base metal was performed, as a part of more extensive research previously conducted. J integral was determined by direct measurement using special instrumentation including strain gauges and a CMOD measuring device. Numerical analysis was performed by 3D finite element method (FEM) with different tensile properties in BM and WM. Results of J-CMOD curves evaluation for SUMITEN SM 80P HSLA steel and its weld metal (WM) are presented and analyzed for small and large cracks in tensile panels. This paper is focused on some new numerical results and observations on crack tip fields and constraint effects of undermatching and crack size keeping in mind previously performed experiments on the full-scale prototype. In this way, a unique combined approach of experimental investigation on the full-scale proto-type and tensile panels, as well as numerical investigation on mismatching and crack size effects, is achieved.",
publisher = "MDPI",
journal = "Materials",
title = "Crack Size and Undermatching Effects on Fracture Behavior of a Welded Joint",
number = "13",
pages = "4858",
volume = "16",
doi = "10.3390/ma16134858"
}

Sedmak, A., Doncheva, E., Međo, B., Rakin, M., Milošević, N.,& Radu, D.. (2023). Crack Size and Undermatching Effects on Fracture Behavior of a Welded Joint. in Materials
MDPI., 16(13), 4858.
https://doi.org/10.3390/ma16134858

Sedmak A, Doncheva E, Međo B, Rakin M, Milošević N, Radu D. Crack Size and Undermatching Effects on Fracture Behavior of a Welded Joint. in Materials. 2023;16(13):4858.
doi:10.3390/ma16134858 .

Sedmak, Aleksandar, Doncheva, Elisaveta, Međo, Bojan, Rakin, Marko, Milošević, Nenad, Radu, Dorin, "Crack Size and Undermatching Effects on Fracture Behavior of a Welded Joint" in Materials, 16, no. 13 (2023):4858,
https://doi.org/10.3390/ma16134858 . .

TY  - JOUR
AU  - Musrati, Walid
AU  - Međo, Bojan
AU  - Cvijović-Alagić, Ivana
AU  - Gubeljak, Nenad
AU  - Štefane, Primož
AU  - Radosavljević, Zoran
AU  - Rakin, Marko
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6607
AB  - Steel pipelines in industrial plants consist of different elements, including seamless and/or welded (seam) pipes. Properties of welded pipes, including their fracture behaviour, depend on the characteristics of both, the base metal, and the weld metal. In this work, two seam pipes are considered having different diameters and manufactured of P235TR1 steel. Hardness and microstructure were examined on the samples which contained the seam zone, to capture the influence of heterogeneity. Fracture resistance of the pipeline material, i.e. of both base metals and both seams, was determined by experimental examination of the recently proposed Pipe ring notch bending specimens with sharp stress concentrators. Differences between the two tested pipes, including the influence of the heterogeneity caused by the welded joint, were determined by comparison of the crack growth resistance curves. Effects of the initial stress concentrator shape, sharp machined notch or fatigue precrack are discussed.
AB  - Čelični cevovodi u industrijskim postrojenjima se sastoje od različitih elemenata, uključujući bešavne i/ili
zavarene (šavne) cevi. Osobine šavnih cevi, uključujući ponašanje materijala cevi pri lomu, zavise i od
osnovnog metala i od metala šava. U ovom radu razmatrane su dve šavne cevi različitih prečnika,
izrađene od čelika P235TR1. Tvrdoća i mikrostruktura su analizirane na uzorcima isečenim iz cevi u zoni
šava, da bi se odredio uticaj heterogenosti. Otpornost prema lomu materijala cevovoda, tj. oba osnovna
metala i oba šava, je određena na osnovu ispitivanja epruveta oblika prstena sa oštrim koncentratorima
napona, predloženih u prethodnim studijama. Poređenjem krivih otpornosti prema rastu prsline
određene su razlike između dve ispitivane cevi, kao i uticaj heterogenosti izazvan postojanjem zavarenog
spoja. Razmotren je uticaj oblika početnog koncentratora napona, oštrog žleba odnosno zamorne
početne prsline.
PB  - Association of the Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters
T1  - Otpornost prema lomu, tvrdoća i mikrostruktura šavnih cevi različitog prečnika izrađenih od čelika P235TR1
EP  - 165
IS  - 2
SP  - 155
VL  - 77
DO  - 10.2298/HEMIND230222016M
ER  - 

@article{
author = "Musrati, Walid and Međo, Bojan and Cvijović-Alagić, Ivana and Gubeljak, Nenad and Štefane, Primož and Radosavljević, Zoran and Rakin, Marko",
year = "2023",
abstract = "Steel pipelines in industrial plants consist of different elements, including seamless and/or welded (seam) pipes. Properties of welded pipes, including their fracture behaviour, depend on the characteristics of both, the base metal, and the weld metal. In this work, two seam pipes are considered having different diameters and manufactured of P235TR1 steel. Hardness and microstructure were examined on the samples which contained the seam zone, to capture the influence of heterogeneity. Fracture resistance of the pipeline material, i.e. of both base metals and both seams, was determined by experimental examination of the recently proposed Pipe ring notch bending specimens with sharp stress concentrators. Differences between the two tested pipes, including the influence of the heterogeneity caused by the welded joint, were determined by comparison of the crack growth resistance curves. Effects of the initial stress concentrator shape, sharp machined notch or fatigue precrack are discussed., Čelični cevovodi u industrijskim postrojenjima se sastoje od različitih elemenata, uključujući bešavne i/ili
zavarene (šavne) cevi. Osobine šavnih cevi, uključujući ponašanje materijala cevi pri lomu, zavise i od
osnovnog metala i od metala šava. U ovom radu razmatrane su dve šavne cevi različitih prečnika,
izrađene od čelika P235TR1. Tvrdoća i mikrostruktura su analizirane na uzorcima isečenim iz cevi u zoni
šava, da bi se odredio uticaj heterogenosti. Otpornost prema lomu materijala cevovoda, tj. oba osnovna
metala i oba šava, je određena na osnovu ispitivanja epruveta oblika prstena sa oštrim koncentratorima
napona, predloženih u prethodnim studijama. Poređenjem krivih otpornosti prema rastu prsline
određene su razlike između dve ispitivane cevi, kao i uticaj heterogenosti izazvan postojanjem zavarenog
spoja. Razmotren je uticaj oblika početnog koncentratora napona, oštrog žleba odnosno zamorne
početne prsline.",
publisher = "Association of the Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters, Otpornost prema lomu, tvrdoća i mikrostruktura šavnih cevi različitog prečnika izrađenih od čelika P235TR1",
pages = "165-155",
number = "2",
volume = "77",
doi = "10.2298/HEMIND230222016M"
}

Musrati, W., Međo, B., Cvijović-Alagić, I., Gubeljak, N., Štefane, P., Radosavljević, Z.,& Rakin, M.. (2023). Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters. in Hemijska industrija
Association of the Chemical Engineers of Serbia., 77(2), 155-165.
https://doi.org/10.2298/HEMIND230222016M

Musrati W, Međo B, Cvijović-Alagić I, Gubeljak N, Štefane P, Radosavljević Z, Rakin M. Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters. in Hemijska industrija. 2023;77(2):155-165.
doi:10.2298/HEMIND230222016M .

Musrati, Walid, Međo, Bojan, Cvijović-Alagić, Ivana, Gubeljak, Nenad, Štefane, Primož, Radosavljević, Zoran, Rakin, Marko, "Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters" in Hemijska industrija, 77, no. 2 (2023):155-165,
https://doi.org/10.2298/HEMIND230222016M . .

TY  - JOUR
AU  - Trajković, Isaak
AU  - Rakin, Marko
AU  - Milošević, Miloš
AU  - Mitrović, Nenad
AU  - Travica, Milan
AU  - Sedmak, Aleksandar
AU  - Međo, Bojan
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6649
AB  - In order to develop a non-standard method for determining the resistance to fracture and damage of pipeline materials, a new geometry of ring-shaped specimens with sharp notches or cracks has been defined. The need to develop a new method for testing of the specimens cut from the pipes arises due to the difficulties in determination of fracture mechanics parameters on thin-walled pressure pipelines, especially those with a smaller cross-section, by application of the standard procedures/specimens. Previous studies dealing with the topic of pipeline testing by non-standard methods are presented in the introductory part of the paper. In the experimental part of the research, tests on PRNT (Pipe Ring Notched Tension) and SENT (Single Edge Notched Tension) specimens are performed. Samples of these specimens were produced by SLS (Selective Laser Sintering) technique of additive production from PA12 (polyamide PA 2200) material. For the purpose of this study, a tool that is protected at the national level (in Serbia) as intellectual property is used for testing of the ring-shaped PRNT specimens. Tensile testing of both types of specimens is monitored by Aramis GOM 2M system; its operation is based on the method of digital image correlation, DIC. Additionally, finite element analyses are conducted on the PRNT and SENT geometries, enabling the calculation of the fracture mechanics parameter – Stress intensity factor K. It is concluded that the presented procedure based on the PRNT specimen has a good potential for use as a non-standard method for fracture resistance examination of pipeline materials. It can be performed on the specimens cut directly from the pipes (new or from exploitation). The dependence of the fracture resistance on the stress concentrator size is not pronounced, which means that the results depend dominantly on the material properties, rather than on geometry.
PB  - Elsevier Ltd.
T2  - Engineering Fracture Mechanics
T1  - Selective laser sintered Pipe Ring Notched Tension specimens for examination of fracture properties of pipeline materials
SP  - 109573
VL  - 292
DO  - 10.1016/j.engfracmech.2023.109573
ER  - 

@article{
author = "Trajković, Isaak and Rakin, Marko and Milošević, Miloš and Mitrović, Nenad and Travica, Milan and Sedmak, Aleksandar and Međo, Bojan",
year = "2023",
abstract = "In order to develop a non-standard method for determining the resistance to fracture and damage of pipeline materials, a new geometry of ring-shaped specimens with sharp notches or cracks has been defined. The need to develop a new method for testing of the specimens cut from the pipes arises due to the difficulties in determination of fracture mechanics parameters on thin-walled pressure pipelines, especially those with a smaller cross-section, by application of the standard procedures/specimens. Previous studies dealing with the topic of pipeline testing by non-standard methods are presented in the introductory part of the paper. In the experimental part of the research, tests on PRNT (Pipe Ring Notched Tension) and SENT (Single Edge Notched Tension) specimens are performed. Samples of these specimens were produced by SLS (Selective Laser Sintering) technique of additive production from PA12 (polyamide PA 2200) material. For the purpose of this study, a tool that is protected at the national level (in Serbia) as intellectual property is used for testing of the ring-shaped PRNT specimens. Tensile testing of both types of specimens is monitored by Aramis GOM 2M system; its operation is based on the method of digital image correlation, DIC. Additionally, finite element analyses are conducted on the PRNT and SENT geometries, enabling the calculation of the fracture mechanics parameter – Stress intensity factor K. It is concluded that the presented procedure based on the PRNT specimen has a good potential for use as a non-standard method for fracture resistance examination of pipeline materials. It can be performed on the specimens cut directly from the pipes (new or from exploitation). The dependence of the fracture resistance on the stress concentrator size is not pronounced, which means that the results depend dominantly on the material properties, rather than on geometry.",
publisher = "Elsevier Ltd.",
journal = "Engineering Fracture Mechanics",
title = "Selective laser sintered Pipe Ring Notched Tension specimens for examination of fracture properties of pipeline materials",
pages = "109573",
volume = "292",
doi = "10.1016/j.engfracmech.2023.109573"
}

Trajković, I., Rakin, M., Milošević, M., Mitrović, N., Travica, M., Sedmak, A.,& Međo, B.. (2023). Selective laser sintered Pipe Ring Notched Tension specimens for examination of fracture properties of pipeline materials. in Engineering Fracture Mechanics
Elsevier Ltd.., 292, 109573.
https://doi.org/10.1016/j.engfracmech.2023.109573

Trajković I, Rakin M, Milošević M, Mitrović N, Travica M, Sedmak A, Međo B. Selective laser sintered Pipe Ring Notched Tension specimens for examination of fracture properties of pipeline materials. in Engineering Fracture Mechanics. 2023;292:109573.
doi:10.1016/j.engfracmech.2023.109573 .

Trajković, Isaak, Rakin, Marko, Milošević, Miloš, Mitrović, Nenad, Travica, Milan, Sedmak, Aleksandar, Međo, Bojan, "Selective laser sintered Pipe Ring Notched Tension specimens for examination of fracture properties of pipeline materials" in Engineering Fracture Mechanics, 292 (2023):109573,
https://doi.org/10.1016/j.engfracmech.2023.109573 . .

TY  - PAT
AU  - Veljić, Darko
AU  - Rakin, Marko
AU  - Međo, Bojan
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6922
AB  - Prikazani pronalazak, modularni alat za zavarivanje trenjem mešanjem sa podesivom dužinom trna kao predmet pronalaska, odnosi se na konstrukciono rešenje alata za zavarivanje u čvrstom stanju legura obojenih metala. Alat se satoji od: tela (1) alata, trna (2) i steznog vijka (3). Gornji deo tela (1) alata služi za stezanje u mašini, a donji deo tela (1) alata poseduje bočni otvor (5) sa navojem za fiksiranje trna (2). Sa donje strane tela (1) alata se nalazi čelo (7) alata sa urezanom levom zavojnicom. Telo (1) alata ima otvor (4) celom dužinom za smeštaj trna (2). Trn (2) ima konusni vrh sa narezanim levim navojem. Moguće je podešavati dužinu trna (2), odnosno rastojanje od vrha trna (2) do čela (7) alata u zavisnosti od vrste spoja i debljine materijala koji se zavaruje. Stezni vijak (3) služi za fiksiranje trna (2) alata na željenu poziciju.
T2  - Zavod za intelektualnu svojinu
T1  - Modularni alat za zavarivanje trenjem mešanjem sa podesivom dužinom trna
IS  - MP-2023/0001
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6922
ER  - 

@misc{
author = "Veljić, Darko and Rakin, Marko and Međo, Bojan",
year = "2023",
abstract = "Prikazani pronalazak, modularni alat za zavarivanje trenjem mešanjem sa podesivom dužinom trna kao predmet pronalaska, odnosi se na konstrukciono rešenje alata za zavarivanje u čvrstom stanju legura obojenih metala. Alat se satoji od: tela (1) alata, trna (2) i steznog vijka (3). Gornji deo tela (1) alata služi za stezanje u mašini, a donji deo tela (1) alata poseduje bočni otvor (5) sa navojem za fiksiranje trna (2). Sa donje strane tela (1) alata se nalazi čelo (7) alata sa urezanom levom zavojnicom. Telo (1) alata ima otvor (4) celom dužinom za smeštaj trna (2). Trn (2) ima konusni vrh sa narezanim levim navojem. Moguće je podešavati dužinu trna (2), odnosno rastojanje od vrha trna (2) do čela (7) alata u zavisnosti od vrste spoja i debljine materijala koji se zavaruje. Stezni vijak (3) služi za fiksiranje trna (2) alata na željenu poziciju.",
journal = "Zavod za intelektualnu svojinu",
title = "Modularni alat za zavarivanje trenjem mešanjem sa podesivom dužinom trna",
number = "MP-2023/0001",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6922"
}

Veljić, D., Rakin, M.,& Međo, B.. (2023). Modularni alat za zavarivanje trenjem mešanjem sa podesivom dužinom trna. in Zavod za intelektualnu svojinu(MP-2023/0001).
https://hdl.handle.net/21.15107/rcub_technorep_6922

Veljić D, Rakin M, Međo B. Modularni alat za zavarivanje trenjem mešanjem sa podesivom dužinom trna. in Zavod za intelektualnu svojinu. 2023;(MP-2023/0001).
https://hdl.handle.net/21.15107/rcub_technorep_6922 .

Veljić, Darko, Rakin, Marko, Međo, Bojan, "Modularni alat za zavarivanje trenjem mešanjem sa podesivom dužinom trna" in Zavod za intelektualnu svojinu, no. MP-2023/0001 (2023),
https://hdl.handle.net/21.15107/rcub_technorep_6922 .

TY  - JOUR
AU  - Trajković, Isaak
AU  - Milošević, Miloš
AU  - Travica, Milan
AU  - Rakin, Marko
AU  - Mladenović, Goran
AU  - Kudrjavceva, Ljudmila
AU  - Međo, Bojan
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5348
AB  - This paper presents a part of development of a non-standard method for testing of cylindrical test specimens for measurement of fracture properties of pipeline materials. This method for testing of cylindrical structures working under pressure is based on determining of fracture mechanics parameters on SENT (Single Edge Notched Tension) specimens and new PRNT (Pipe Ring Notched Tension) specimens. In this work, both types of specimens required for this testing were manufactured from polyamide PA12 by using SLS (selective laser sintering) additive manufacturing method. Testing of the specimens is performed on the universal device for testing of mechanical properties of materials Shimadzu, AGS-X 100 kN. The tensile testing is accompanied by GOM Aramis 2M system, used for digital image correlation. By using these two systems, test results are obtained for ring-shaped and SENT specimens, including forces, displacements and fracture mechanics parameters CMOD (Crack Mouth Opening Displacement) and CTOD-δ5 (Crack Tip Opening Displacement obtained by δ5 technique), as well as crack growth. Repeatability of this process, along with valid result consistency, represent the basis for further development of the new method, including the determining of energy-based fracture mechanics parameters: J integral and stress intensity factor.
PB  - International Institute for the Science of Sintering (IISS)
T2  - Science of Sintering
T1  - Novel Method for Measurement of Pipeline Materials Fracture Resistance-Examination on Selective Laser Sintered Cylindrical Specimens
EP  - 386
IS  - 3
SP  - 373
VL  - 54
DO  - 10.2298/SOS2203373T
ER  - 

@article{
author = "Trajković, Isaak and Milošević, Miloš and Travica, Milan and Rakin, Marko and Mladenović, Goran and Kudrjavceva, Ljudmila and Međo, Bojan",
year = "2022",
abstract = "This paper presents a part of development of a non-standard method for testing of cylindrical test specimens for measurement of fracture properties of pipeline materials. This method for testing of cylindrical structures working under pressure is based on determining of fracture mechanics parameters on SENT (Single Edge Notched Tension) specimens and new PRNT (Pipe Ring Notched Tension) specimens. In this work, both types of specimens required for this testing were manufactured from polyamide PA12 by using SLS (selective laser sintering) additive manufacturing method. Testing of the specimens is performed on the universal device for testing of mechanical properties of materials Shimadzu, AGS-X 100 kN. The tensile testing is accompanied by GOM Aramis 2M system, used for digital image correlation. By using these two systems, test results are obtained for ring-shaped and SENT specimens, including forces, displacements and fracture mechanics parameters CMOD (Crack Mouth Opening Displacement) and CTOD-δ5 (Crack Tip Opening Displacement obtained by δ5 technique), as well as crack growth. Repeatability of this process, along with valid result consistency, represent the basis for further development of the new method, including the determining of energy-based fracture mechanics parameters: J integral and stress intensity factor.",
publisher = "International Institute for the Science of Sintering (IISS)",
journal = "Science of Sintering",
title = "Novel Method for Measurement of Pipeline Materials Fracture Resistance-Examination on Selective Laser Sintered Cylindrical Specimens",
pages = "386-373",
number = "3",
volume = "54",
doi = "10.2298/SOS2203373T"
}

Trajković, I., Milošević, M., Travica, M., Rakin, M., Mladenović, G., Kudrjavceva, L.,& Međo, B.. (2022). Novel Method for Measurement of Pipeline Materials Fracture Resistance-Examination on Selective Laser Sintered Cylindrical Specimens. in Science of Sintering
International Institute for the Science of Sintering (IISS)., 54(3), 373-386.
https://doi.org/10.2298/SOS2203373T

Trajković I, Milošević M, Travica M, Rakin M, Mladenović G, Kudrjavceva L, Međo B. Novel Method for Measurement of Pipeline Materials Fracture Resistance-Examination on Selective Laser Sintered Cylindrical Specimens. in Science of Sintering. 2022;54(3):373-386.
doi:10.2298/SOS2203373T .

Trajković, Isaak, Milošević, Miloš, Travica, Milan, Rakin, Marko, Mladenović, Goran, Kudrjavceva, Ljudmila, Međo, Bojan, "Novel Method for Measurement of Pipeline Materials Fracture Resistance-Examination on Selective Laser Sintered Cylindrical Specimens" in Science of Sintering, 54, no. 3 (2022):373-386,
https://doi.org/10.2298/SOS2203373T . .

TY  - CONF
AU  - Rakin, Marko
AU  - Barjaktarević, Dragana
AU  - Međo, Bojan
AU  - Đokić, Veljko
AU  - Gubeljak, Nenad
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6012
AB  - The intent of the study was to modify virgin biomedical Ti-13Nb-13Zr alloy in aim to realize whether applied modifications could improve mechanical properties. Two groups of modifications were applied to the prepared samples: structural modification achieved by severe plastic deformation (SPD) and modification of alloy surface obtained by electrochemical method. Structural modification was performed by using high pressure torsion (HPT) as one of the SPD methods. Pressure of 4.1 GPa was applied and up to 5 rotations were made at room temperature. After HPT treatment an ultrafine-grained (UFG) structure was obtained. The homogeneity of the UFG alloy was checked by using Vickers microhardness tester. Electrochemical anodization was done in the 1M H3PO4 + NaF electrolyte during 90 minutes, resulting in formation of an oxide layer on the alloy surface. Surface roughness was determined using an atomic force microscope. Tensile properties of the alloy before and after electrochemical anodization and HPT processing were determined. The scanning electron microscopy was used to characterize both morphology of anodized surfaces and the fracture surfaces after the tensile tests. 
The HPT treated alloy has higher values of tensile strength and modulus of elasticity and lower value of plasticity than the virgin alloy. Surface modification of virgin alloy leads to a decrease of these values compared to non-treated samples and practically has no influence on tensile properties on the UFG alloy. Mechanical properties of the surface – modulus of elasticity and nanohardness were determined using a nanoindentation test. The surfaces of anodized alloys (both virgin and HPT treated) have lower modulus of elasticity than surfaces of non-anodized ones.
C3  - 4th Virtual Congress on Materials Science & Engineering
T1  - Mechanical characterization of surface modified Ti-based alloy before and after severe plastic deformation
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6012
ER  - 

@conference{
author = "Rakin, Marko and Barjaktarević, Dragana and Međo, Bojan and Đokić, Veljko and Gubeljak, Nenad",
year = "2022",
abstract = "The intent of the study was to modify virgin biomedical Ti-13Nb-13Zr alloy in aim to realize whether applied modifications could improve mechanical properties. Two groups of modifications were applied to the prepared samples: structural modification achieved by severe plastic deformation (SPD) and modification of alloy surface obtained by electrochemical method. Structural modification was performed by using high pressure torsion (HPT) as one of the SPD methods. Pressure of 4.1 GPa was applied and up to 5 rotations were made at room temperature. After HPT treatment an ultrafine-grained (UFG) structure was obtained. The homogeneity of the UFG alloy was checked by using Vickers microhardness tester. Electrochemical anodization was done in the 1M H3PO4 + NaF electrolyte during 90 minutes, resulting in formation of an oxide layer on the alloy surface. Surface roughness was determined using an atomic force microscope. Tensile properties of the alloy before and after electrochemical anodization and HPT processing were determined. The scanning electron microscopy was used to characterize both morphology of anodized surfaces and the fracture surfaces after the tensile tests. 
The HPT treated alloy has higher values of tensile strength and modulus of elasticity and lower value of plasticity than the virgin alloy. Surface modification of virgin alloy leads to a decrease of these values compared to non-treated samples and practically has no influence on tensile properties on the UFG alloy. Mechanical properties of the surface – modulus of elasticity and nanohardness were determined using a nanoindentation test. The surfaces of anodized alloys (both virgin and HPT treated) have lower modulus of elasticity than surfaces of non-anodized ones.",
journal = "4th Virtual Congress on Materials Science & Engineering",
title = "Mechanical characterization of surface modified Ti-based alloy before and after severe plastic deformation",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6012"
}

Rakin, M., Barjaktarević, D., Međo, B., Đokić, V.,& Gubeljak, N.. (2022). Mechanical characterization of surface modified Ti-based alloy before and after severe plastic deformation. in 4th Virtual Congress on Materials Science & Engineering.
https://hdl.handle.net/21.15107/rcub_technorep_6012

Rakin M, Barjaktarević D, Međo B, Đokić V, Gubeljak N. Mechanical characterization of surface modified Ti-based alloy before and after severe plastic deformation. in 4th Virtual Congress on Materials Science & Engineering. 2022;.
https://hdl.handle.net/21.15107/rcub_technorep_6012 .

Rakin, Marko, Barjaktarević, Dragana, Međo, Bojan, Đokić, Veljko, Gubeljak, Nenad, "Mechanical characterization of surface modified Ti-based alloy before and after severe plastic deformation" in 4th Virtual Congress on Materials Science & Engineering (2022),
https://hdl.handle.net/21.15107/rcub_technorep_6012 .

TY  - CONF
AU  - Laketić, Slađana
AU  - Rakin, Marko
AU  - Momčilović, Miloš
AU  - Ciganović, Jovan
AU  - Veljović, Đorđe
AU  - Cvijović, Ivana
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6009
AB  - Titanium alloys are finding increasing use as biomaterials due to their low elastic modulus and high damage tolerance. However, the somewhat inadequate alloy surface performance can impede their biomedical application. Surface modification methods have been therefore developed to improve the alloys' surface bioactivity and osseointegration. Laser treatment allows the alloy surface to be modified, providing it with new functionalized surface chemistry and morphology, without compromising the rest of the material properties. Thus, the aim of the study was to examine the laser-induced alterations generated on the Ti-45Nb alloy surface by an ultrashort pulsed laser. The obtained results reveal that laser beam interaction with the target material led to the formation of significant alterations in surface morphology. Surface craters, microcracks, and surface features in the form of periodic and rippled structures and solidified droplets can be observed in the irradiated area. Also, it was found that the higher damage degree along with the material depth and the higher surface roughness were achieved during the irradiation in the argon atmosphere due to the formation of the more pronounced morphological changes on the alloy surface that are induced by higher laser ablation. Furthermore, obtained results showed that alloy surface modification in air, argon, and nitrogen atmosphere additionally caused changes in the surface chemical composition. Namely, after irradiation, the presence of oxygen was observed in the central irradiated area indicating the formation of bioactive Ti-oxide surface film with content that varies with the irradiation parameters variation. Therefore, laser beam irradiation can be singled out as the surface modification method for efficient inducement of the specific surface characteristics that can provide titanium alloys with enhanced osseointegration properties.
PB  - Materials Research Society of Serbia – MRS-Serbia
C3  - TWENTY THIRD ANNUAL CONFERENCE - YUCOMAT
T1  - Laser-induced chemical and mophological changes of the titanium alloy surface under different irradiation parameters
SP  - 92
VL  - XLV
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6009
ER  - 

@conference{
author = "Laketić, Slađana and Rakin, Marko and Momčilović, Miloš and Ciganović, Jovan and Veljović, Đorđe and Cvijović, Ivana",
year = "2022",
abstract = "Titanium alloys are finding increasing use as biomaterials due to their low elastic modulus and high damage tolerance. However, the somewhat inadequate alloy surface performance can impede their biomedical application. Surface modification methods have been therefore developed to improve the alloys' surface bioactivity and osseointegration. Laser treatment allows the alloy surface to be modified, providing it with new functionalized surface chemistry and morphology, without compromising the rest of the material properties. Thus, the aim of the study was to examine the laser-induced alterations generated on the Ti-45Nb alloy surface by an ultrashort pulsed laser. The obtained results reveal that laser beam interaction with the target material led to the formation of significant alterations in surface morphology. Surface craters, microcracks, and surface features in the form of periodic and rippled structures and solidified droplets can be observed in the irradiated area. Also, it was found that the higher damage degree along with the material depth and the higher surface roughness were achieved during the irradiation in the argon atmosphere due to the formation of the more pronounced morphological changes on the alloy surface that are induced by higher laser ablation. Furthermore, obtained results showed that alloy surface modification in air, argon, and nitrogen atmosphere additionally caused changes in the surface chemical composition. Namely, after irradiation, the presence of oxygen was observed in the central irradiated area indicating the formation of bioactive Ti-oxide surface film with content that varies with the irradiation parameters variation. Therefore, laser beam irradiation can be singled out as the surface modification method for efficient inducement of the specific surface characteristics that can provide titanium alloys with enhanced osseointegration properties.",
publisher = "Materials Research Society of Serbia – MRS-Serbia",
journal = "TWENTY THIRD ANNUAL CONFERENCE - YUCOMAT",
title = "Laser-induced chemical and mophological changes of the titanium alloy surface under different irradiation parameters",
pages = "92",
volume = "XLV",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6009"
}

Laketić, S., Rakin, M., Momčilović, M., Ciganović, J., Veljović, Đ.,& Cvijović, I.. (2022). Laser-induced chemical and mophological changes of the titanium alloy surface under different irradiation parameters. in TWENTY THIRD ANNUAL CONFERENCE - YUCOMAT
Materials Research Society of Serbia – MRS-Serbia., XLV, 92.
https://hdl.handle.net/21.15107/rcub_technorep_6009

Laketić S, Rakin M, Momčilović M, Ciganović J, Veljović Đ, Cvijović I. Laser-induced chemical and mophological changes of the titanium alloy surface under different irradiation parameters. in TWENTY THIRD ANNUAL CONFERENCE - YUCOMAT. 2022;XLV:92.
https://hdl.handle.net/21.15107/rcub_technorep_6009 .

Laketić, Slađana, Rakin, Marko, Momčilović, Miloš, Ciganović, Jovan, Veljović, Đorđe, Cvijović, Ivana, "Laser-induced chemical and mophological changes of the titanium alloy surface under different irradiation parameters" in TWENTY THIRD ANNUAL CONFERENCE - YUCOMAT, XLV (2022):92,
https://hdl.handle.net/21.15107/rcub_technorep_6009 .

TY  - CONF
AU  - Trajković, Isaak
AU  - Milošević, Miloš
AU  - Travica, Milan
AU  - Rakin, Marko
AU  - Jevtić, Ivana
AU  - Sedmak, Aleksandar
AU  - Međo, Bojan
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6010
AB  - This work presents the fabrication and tensile testing of polyamide specimens fabricated by
selective laser sintering (SLS). Two geometries are considered: SENT (Single Edge Notched
Tension) and PRNT (Pipe Ring Notched Tension) specimens. Experimental testing of these
specimens is a step in development of a new method for testing of properties of the pipeline
materials. The samples were produced by SLS (Selective Laser Sintering) additive production
technique. The samples were made from polyamide PA12 on EOS Formiga P100 machine
(fabrication parameters: laser power 30 W, print layer height 0.1 mm, scanning speed 1.6-5
m/s, operating temperature 170⁰C). Testing was performed in the displacement control on a
universal tensile testing machine Shimadzu AGS - X. On this machine, the values of force as
well as the values of stress and strain were obtained directly from the Trapezium X software.
Special attention in this work is devoted to two important aspects: fixing of the ring specimen
for testing and influence of friction between the specimen and the tool. The results obtained
on the examined specimens indicate that this study is a valuable contribution for further
development and verification of the new fracture resistance testing procedure for different
pipeline materials.
PB  - Serbian Academy of Sciences and Arts
C3  - Serbian Ceramic Society Conference ADVANCED CERAMICS AND APPLICATION X New Frontiers in Multifunctional Material Science and Processing
T1  - Laser sintered polyamide specimens - fabrication and tensile testing conditions on different geometries
SP  - 80
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6010
ER  - 

@conference{
author = "Trajković, Isaak and Milošević, Miloš and Travica, Milan and Rakin, Marko and Jevtić, Ivana and Sedmak, Aleksandar and Međo, Bojan",
year = "2022",
abstract = "This work presents the fabrication and tensile testing of polyamide specimens fabricated by
selective laser sintering (SLS). Two geometries are considered: SENT (Single Edge Notched
Tension) and PRNT (Pipe Ring Notched Tension) specimens. Experimental testing of these
specimens is a step in development of a new method for testing of properties of the pipeline
materials. The samples were produced by SLS (Selective Laser Sintering) additive production
technique. The samples were made from polyamide PA12 on EOS Formiga P100 machine
(fabrication parameters: laser power 30 W, print layer height 0.1 mm, scanning speed 1.6-5
m/s, operating temperature 170⁰C). Testing was performed in the displacement control on a
universal tensile testing machine Shimadzu AGS - X. On this machine, the values of force as
well as the values of stress and strain were obtained directly from the Trapezium X software.
Special attention in this work is devoted to two important aspects: fixing of the ring specimen
for testing and influence of friction between the specimen and the tool. The results obtained
on the examined specimens indicate that this study is a valuable contribution for further
development and verification of the new fracture resistance testing procedure for different
pipeline materials.",
publisher = "Serbian Academy of Sciences and Arts",
journal = "Serbian Ceramic Society Conference ADVANCED CERAMICS AND APPLICATION X New Frontiers in Multifunctional Material Science and Processing",
title = "Laser sintered polyamide specimens - fabrication and tensile testing conditions on different geometries",
pages = "80",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6010"
}

Trajković, I., Milošević, M., Travica, M., Rakin, M., Jevtić, I., Sedmak, A.,& Međo, B.. (2022). Laser sintered polyamide specimens - fabrication and tensile testing conditions on different geometries. in Serbian Ceramic Society Conference ADVANCED CERAMICS AND APPLICATION X New Frontiers in Multifunctional Material Science and Processing
Serbian Academy of Sciences and Arts., 80.
https://hdl.handle.net/21.15107/rcub_technorep_6010

Trajković I, Milošević M, Travica M, Rakin M, Jevtić I, Sedmak A, Međo B. Laser sintered polyamide specimens - fabrication and tensile testing conditions on different geometries. in Serbian Ceramic Society Conference ADVANCED CERAMICS AND APPLICATION X New Frontiers in Multifunctional Material Science and Processing. 2022;:80.
https://hdl.handle.net/21.15107/rcub_technorep_6010 .

Trajković, Isaak, Milošević, Miloš, Travica, Milan, Rakin, Marko, Jevtić, Ivana, Sedmak, Aleksandar, Međo, Bojan, "Laser sintered polyamide specimens - fabrication and tensile testing conditions on different geometries" in Serbian Ceramic Society Conference ADVANCED CERAMICS AND APPLICATION X New Frontiers in Multifunctional Material Science and Processing (2022):80,
https://hdl.handle.net/21.15107/rcub_technorep_6010 .

TY  - CONF
AU  - Cvijović-Alagić, Ivana
AU  - Laketić, Slađana
AU  - Momčilović, Miloš
AU  - Ciganović, Jovan
AU  - Veljović, Đorđe
AU  - Rakin, Marko
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6011
AB  - Hard-tissue replacements are most commonly made from the Ti-based materials, such as
commercially pure titanium (CP-Ti) and Ti-6Al-4V (mass%) alloy, because of their exceptional
biocompatible properties combined with the excellent corrosive and mechanical characteristics [1].
More recently, efforts have been made to additionally enhance the properties of the metallic
implants through the careful selection of the alloy composition and surface modification technics
[2,3]. As a result, second-generation β-type Ti alloys, containing non-toxic elements, have been
developed. One of the promising β-type implant alloys is Ti-13Nb-13Zr (mass%). Even though the
corrosion resistance and mechanical properties of this alloy are improved in comparison to the
commonly used metallic implant materials, its biocompatible and osseointegration properties can
and must be additionally enhanced. For that purpose several surface modification technics can be
used, however, laser irradiation stands out as the most promising one. Because of that scope of the
present research was to investigate the possibility of successful surface modification of the most
commonly used implant material, i.e. CP-Ti, and the second-generation Ti-13Nb-13Zr alloy by
utilizing the easy-to-apply laser irradiation method in order to obtain improved implant tribocorrosive
properties and enhanced biointegration and bioactivity.
Laser surface modifications were conducted using the Nd:YAG system in the air and argon
atmosphere under different laser output energies. Implant materials surface morphologies after the
laser irradiation treatment were investigated using the field-emission scanning electron microscopy
(FE-SEM) and optical profilometry, while the impact of the laser irradiation on the implant
materials surface characteristics were examined using the energy dispersive spectrometry (EDS)
and microhardness measurements.
Conducted research showed that utilization of the Nd:YAG laser irradiation resulted in significant
alterations of the CP-Ti and Ti-13Nb-13Zr alloy surface chemistry, morphology and microhardness.
Laser irradiation of both investigated materials led to the formation of visible microcracks and
hydrodynamic effects in the central part of the irradiated area, while traces of melted and solidified
material were observed at its periphery. More pronounced morphological changes were induced
during the laser irradiation in an argon atmosphere, while a higher degree of texturing was recorded
at the surface of the Ti-13Nb-13Zr alloy. At the irradiated surfaces, the formation of the oxide layer,
predominantly composed of Ti-oxide particles, was detected. Surface oxides are desirable since
their presence can improve the implant material bioactivity with a simultaneous increase of the
tribo-corrosive properties through the formation of the hard corrosion resistance surface film. Laserinduced
chemical and morphological alterations were more distinctive in the case of the Ti-13Nb-
13Zr alloy.
PB  - Vinča Institute of Nuclear Sciences - National Institute of thе Republic of Serbia, University of Belgrade
PB  - Serbian Society for Innovative Materials in Extreme Conditions (SIM-EXTREME)
C3  - 1st International Conference on Innovative Materials in Extreme Conditions (IMEC2022)
T1  - Laser irradiation as an easy-to-apply method for Ti-based implant materials enhancement
SP  - 20
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6011
ER  - 

@conference{
author = "Cvijović-Alagić, Ivana and Laketić, Slađana and Momčilović, Miloš and Ciganović, Jovan and Veljović, Đorđe and Rakin, Marko",
year = "2022",
abstract = "Hard-tissue replacements are most commonly made from the Ti-based materials, such as
commercially pure titanium (CP-Ti) and Ti-6Al-4V (mass%) alloy, because of their exceptional
biocompatible properties combined with the excellent corrosive and mechanical characteristics [1].
More recently, efforts have been made to additionally enhance the properties of the metallic
implants through the careful selection of the alloy composition and surface modification technics
[2,3]. As a result, second-generation β-type Ti alloys, containing non-toxic elements, have been
developed. One of the promising β-type implant alloys is Ti-13Nb-13Zr (mass%). Even though the
corrosion resistance and mechanical properties of this alloy are improved in comparison to the
commonly used metallic implant materials, its biocompatible and osseointegration properties can
and must be additionally enhanced. For that purpose several surface modification technics can be
used, however, laser irradiation stands out as the most promising one. Because of that scope of the
present research was to investigate the possibility of successful surface modification of the most
commonly used implant material, i.e. CP-Ti, and the second-generation Ti-13Nb-13Zr alloy by
utilizing the easy-to-apply laser irradiation method in order to obtain improved implant tribocorrosive
properties and enhanced biointegration and bioactivity.
Laser surface modifications were conducted using the Nd:YAG system in the air and argon
atmosphere under different laser output energies. Implant materials surface morphologies after the
laser irradiation treatment were investigated using the field-emission scanning electron microscopy
(FE-SEM) and optical profilometry, while the impact of the laser irradiation on the implant
materials surface characteristics were examined using the energy dispersive spectrometry (EDS)
and microhardness measurements.
Conducted research showed that utilization of the Nd:YAG laser irradiation resulted in significant
alterations of the CP-Ti and Ti-13Nb-13Zr alloy surface chemistry, morphology and microhardness.
Laser irradiation of both investigated materials led to the formation of visible microcracks and
hydrodynamic effects in the central part of the irradiated area, while traces of melted and solidified
material were observed at its periphery. More pronounced morphological changes were induced
during the laser irradiation in an argon atmosphere, while a higher degree of texturing was recorded
at the surface of the Ti-13Nb-13Zr alloy. At the irradiated surfaces, the formation of the oxide layer,
predominantly composed of Ti-oxide particles, was detected. Surface oxides are desirable since
their presence can improve the implant material bioactivity with a simultaneous increase of the
tribo-corrosive properties through the formation of the hard corrosion resistance surface film. Laserinduced
chemical and morphological alterations were more distinctive in the case of the Ti-13Nb-
13Zr alloy.",
publisher = "Vinča Institute of Nuclear Sciences - National Institute of thе Republic of Serbia, University of Belgrade, Serbian Society for Innovative Materials in Extreme Conditions (SIM-EXTREME)",
journal = "1st International Conference on Innovative Materials in Extreme Conditions (IMEC2022)",
title = "Laser irradiation as an easy-to-apply method for Ti-based implant materials enhancement",
pages = "20",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6011"
}

Cvijović-Alagić, I., Laketić, S., Momčilović, M., Ciganović, J., Veljović, Đ.,& Rakin, M.. (2022). Laser irradiation as an easy-to-apply method for Ti-based implant materials enhancement. in 1st International Conference on Innovative Materials in Extreme Conditions (IMEC2022)
Vinča Institute of Nuclear Sciences - National Institute of thе Republic of Serbia, University of Belgrade., 20.
https://hdl.handle.net/21.15107/rcub_technorep_6011

Cvijović-Alagić I, Laketić S, Momčilović M, Ciganović J, Veljović Đ, Rakin M. Laser irradiation as an easy-to-apply method for Ti-based implant materials enhancement. in 1st International Conference on Innovative Materials in Extreme Conditions (IMEC2022). 2022;:20.
https://hdl.handle.net/21.15107/rcub_technorep_6011 .

Cvijović-Alagić, Ivana, Laketić, Slađana, Momčilović, Miloš, Ciganović, Jovan, Veljović, Đorđe, Rakin, Marko, "Laser irradiation as an easy-to-apply method for Ti-based implant materials enhancement" in 1st International Conference on Innovative Materials in Extreme Conditions (IMEC2022) (2022):20,
https://hdl.handle.net/21.15107/rcub_technorep_6011 .

TY  - CONF
AU  - Rakin, Marko
AU  - Međo, Bojan
AU  - Musrati, Walid
AU  - Gubeljak, Nenad
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6179
AB  - In recent years, several attempts have been made by research groups worldwide to propose and verify new laboratory specimens
for measurement of pipeline materials fracture resistance. The main reason for these efforts is the requirement of standard
fracture mechanics procedures for relatively large specimen thickness, i.e. plane strain conditions. It is almost impossible,
and also too conservative, to apply such an approach to the thin-walled pipes, which form the majority of industrial pipelines.
Failure resistance of pipeline steel is examined by testing the recently proposed Pipe Ring Notched Bend (PRNB) specimens
with different dimensions. The seam, i.e. longitudinal weld, is analysed as a source of material heterogeneity;
however, seamless pipes are also examined. The results are repeatable, and the dependence on the specimen geometry is
not significant (it is even lower than it could be expected from standard thick fracture mechanics specimens). The seam
materials (weld metals) have shown different fracture behaviour for different batches/sizes of the pipes; they have either
lower or similar fracture resistance in comparison with the base material. Briefly, it can be said that fracture testing of a
relatively small amount of specimens revealed a lot of important data about the resistance of the pipes to ductile failure.
Fracture is modelled by application of the micromechanical approach in software package Abaqus, in particular the
Complete Gurson model. Additionally, the model is used for prediction of fracture resistance in plane strain conditions.
This can be useful for comparison of the examined pipe materials and others with known plane strain fracture properties.
Currently, the authors are working on a new geometry: pipe rings with a sharp notch exposed to tensile loading. This
will form a comprehensive approach to pipeline testing, where two geometries and two loading regimes (bending and
tension) will be available in the framework of a unified testing procedure.
C3  - 3rd Global Webinar on Materials Science and Engineering
T1  - Failure assessment of steel pipes using non-standard ring specimens.
SP  - 11
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6179
ER  - 

@conference{
author = "Rakin, Marko and Međo, Bojan and Musrati, Walid and Gubeljak, Nenad",
year = "2022",
abstract = "In recent years, several attempts have been made by research groups worldwide to propose and verify new laboratory specimens
for measurement of pipeline materials fracture resistance. The main reason for these efforts is the requirement of standard
fracture mechanics procedures for relatively large specimen thickness, i.e. plane strain conditions. It is almost impossible,
and also too conservative, to apply such an approach to the thin-walled pipes, which form the majority of industrial pipelines.
Failure resistance of pipeline steel is examined by testing the recently proposed Pipe Ring Notched Bend (PRNB) specimens
with different dimensions. The seam, i.e. longitudinal weld, is analysed as a source of material heterogeneity;
however, seamless pipes are also examined. The results are repeatable, and the dependence on the specimen geometry is
not significant (it is even lower than it could be expected from standard thick fracture mechanics specimens). The seam
materials (weld metals) have shown different fracture behaviour for different batches/sizes of the pipes; they have either
lower or similar fracture resistance in comparison with the base material. Briefly, it can be said that fracture testing of a
relatively small amount of specimens revealed a lot of important data about the resistance of the pipes to ductile failure.
Fracture is modelled by application of the micromechanical approach in software package Abaqus, in particular the
Complete Gurson model. Additionally, the model is used for prediction of fracture resistance in plane strain conditions.
This can be useful for comparison of the examined pipe materials and others with known plane strain fracture properties.
Currently, the authors are working on a new geometry: pipe rings with a sharp notch exposed to tensile loading. This
will form a comprehensive approach to pipeline testing, where two geometries and two loading regimes (bending and
tension) will be available in the framework of a unified testing procedure.",
journal = "3rd Global Webinar on Materials Science and Engineering",
title = "Failure assessment of steel pipes using non-standard ring specimens.",
pages = "11",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6179"
}

Rakin, M., Međo, B., Musrati, W.,& Gubeljak, N.. (2022). Failure assessment of steel pipes using non-standard ring specimens.. in 3rd Global Webinar on Materials Science and Engineering, 11.
https://hdl.handle.net/21.15107/rcub_technorep_6179

Rakin M, Međo B, Musrati W, Gubeljak N. Failure assessment of steel pipes using non-standard ring specimens.. in 3rd Global Webinar on Materials Science and Engineering. 2022;:11.
https://hdl.handle.net/21.15107/rcub_technorep_6179 .

Rakin, Marko, Međo, Bojan, Musrati, Walid, Gubeljak, Nenad, "Failure assessment of steel pipes using non-standard ring specimens." in 3rd Global Webinar on Materials Science and Engineering (2022):11,
https://hdl.handle.net/21.15107/rcub_technorep_6179 .

TY  - CONF
AU  - Trajković, Isaak
AU  - Milošević, Miloš
AU  - Rakin, Marko
AU  - Sedmak, Aleksandar
AU  - Međo, Bojan
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6421
AB  - In order to define a procedure for integrity assessment of pipelines and determining the fracture mechanics parameters, a new type of specimen with a sharp notch, Pipe Ring Notched Tension (PRNT) specimen, is tested. The aim of the study is to determine the influence of the specimen geometry (cylindrical shape, as well as number and length of stress concentrators) on parameters such as force, Crack Mouth Opening Displacement CMOD, Crack Tip Opening Displacement CTOD and J integral. The specimens were fabricated by an additive production method - selective laser sintering (SLS). EOS Formiga P100 machine is used, and the material is polyamide PA12. In addition to Pipe Ring Notched Tension specimens, Single Edge Notched Tension (SENT) specimens with identical cross section were also considered. All specimens were tested on a universal tensile testing machine. A tool specially designed to apply contact pressure to the inner walls in the tension direction was used, simulating the internal pressure. For determining the field of displacement and strain on the surface of the tested samples that occur during the loading, Aramis GOM 2M optical measurement system was used. Aramis is applied for determination of geometry fracture mechanics parameters: CMOD and CTOD (based on δ5 concept). In addition to the examination of fracture properties of additively manufactured PA12, the main topic of this work is the development of the non-standard testing procedure, which will be subsequently applied to the specimens cut from metallic or non-metallic pipes. As an important part of this procedure, the calculation of fracture parameters will be conducted based on the results presented here.
PB  - Elsevier B.V.
C3  - Procedia Structural Integrity
T1  - Additively manufactured tensile ring-shaped specimens for pipeline material fracture examination - influence of geometry
EP  - 1319
SP  - 1314
VL  - 42
DO  - 10.1016/j.prostr.2022.12.167
ER  - 

@conference{
author = "Trajković, Isaak and Milošević, Miloš and Rakin, Marko and Sedmak, Aleksandar and Međo, Bojan",
year = "2022",
abstract = "In order to define a procedure for integrity assessment of pipelines and determining the fracture mechanics parameters, a new type of specimen with a sharp notch, Pipe Ring Notched Tension (PRNT) specimen, is tested. The aim of the study is to determine the influence of the specimen geometry (cylindrical shape, as well as number and length of stress concentrators) on parameters such as force, Crack Mouth Opening Displacement CMOD, Crack Tip Opening Displacement CTOD and J integral. The specimens were fabricated by an additive production method - selective laser sintering (SLS). EOS Formiga P100 machine is used, and the material is polyamide PA12. In addition to Pipe Ring Notched Tension specimens, Single Edge Notched Tension (SENT) specimens with identical cross section were also considered. All specimens were tested on a universal tensile testing machine. A tool specially designed to apply contact pressure to the inner walls in the tension direction was used, simulating the internal pressure. For determining the field of displacement and strain on the surface of the tested samples that occur during the loading, Aramis GOM 2M optical measurement system was used. Aramis is applied for determination of geometry fracture mechanics parameters: CMOD and CTOD (based on δ5 concept). In addition to the examination of fracture properties of additively manufactured PA12, the main topic of this work is the development of the non-standard testing procedure, which will be subsequently applied to the specimens cut from metallic or non-metallic pipes. As an important part of this procedure, the calculation of fracture parameters will be conducted based on the results presented here.",
publisher = "Elsevier B.V.",
journal = "Procedia Structural Integrity",
title = "Additively manufactured tensile ring-shaped specimens for pipeline material fracture examination - influence of geometry",
pages = "1319-1314",
volume = "42",
doi = "10.1016/j.prostr.2022.12.167"
}

Trajković, I., Milošević, M., Rakin, M., Sedmak, A.,& Međo, B.. (2022). Additively manufactured tensile ring-shaped specimens for pipeline material fracture examination - influence of geometry. in Procedia Structural Integrity
Elsevier B.V.., 42, 1314-1319.
https://doi.org/10.1016/j.prostr.2022.12.167

Trajković I, Milošević M, Rakin M, Sedmak A, Međo B. Additively manufactured tensile ring-shaped specimens for pipeline material fracture examination - influence of geometry. in Procedia Structural Integrity. 2022;42:1314-1319.
doi:10.1016/j.prostr.2022.12.167 .

Trajković, Isaak, Milošević, Miloš, Rakin, Marko, Sedmak, Aleksandar, Međo, Bojan, "Additively manufactured tensile ring-shaped specimens for pipeline material fracture examination - influence of geometry" in Procedia Structural Integrity, 42 (2022):1314-1319,
https://doi.org/10.1016/j.prostr.2022.12.167 . .

TY  - CONF
AU  - Barjaktarević, Dragana
AU  - Rakin, Marko
AU  - Veljović, Đorđe
AU  - Međo, Bojan
AU  - Đokić, Veljko
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5258
AB  - Nanostructured surface of Ti-13Nb-13Zr alloy (coarse-grained (CG), and ultrafine-grained (UFG), obtained by high pressure torsion - HPT) was formed using electrochemical anodization in the 1M H3PO4 + NaF electrolyte, during 30, 60, 90 and 120 minutes. The scanning electron microscopy (SEM) was used to characterise the morphology of the surface, while chemical characterization of the obtained nanostructured surface was performed using energy dispersive spectroscopy (EDS). The surface modulus of elasticity and hardness before and after the surface nanostructure modification, was examined using the nanoindentation test, while the analysis of deformation and damage of the nanostructured surface after nanoindentation was performed using SEM. Cytotoxicity of the tested alloys and cell culture viability were assessed using the tetrazolium salt colorimetric test (MTT test) using mouse fibroblasts (L-929) and human lung fibroblasts (MRC-5) in liquid medium. Morphology and adhesion of cells on the surface were analysed using SEM. The obtained results indicate the strong influence of time, as a parameter of anodization, on the surface morphology. Influence of the HPT processing on the homogeneity of the nanostructured surface obtained by electrochemical anodization has also been shown. The alloys before and after the surface nanostructure modification are adequate in their biocompatibility for use in the implantology. Characterization of the titanium-based materials surface using nanoindentation showed a decrease in the values of modulus of elasticity and hardness for materials with nanostructured surface, which are close to the values of bone tissue in the human body.
PB  - Materials Research Society of Srebia
C3  - Twenty-third Annual Conference YUCOMAT 2022 &
Twelfth World Round Table Conference on Sintering XII WRTCS
T1  - Nanostructured surface modification and characterization of titanium based materials for medical application
SP  - 154
UR  - https://hdl.handle.net/21.15107/rcub_technorep_5258
ER  - 

@conference{
author = "Barjaktarević, Dragana and Rakin, Marko and Veljović, Đorđe and Međo, Bojan and Đokić, Veljko",
year = "2022",
abstract = "Nanostructured surface of Ti-13Nb-13Zr alloy (coarse-grained (CG), and ultrafine-grained (UFG), obtained by high pressure torsion - HPT) was formed using electrochemical anodization in the 1M H3PO4 + NaF electrolyte, during 30, 60, 90 and 120 minutes. The scanning electron microscopy (SEM) was used to characterise the morphology of the surface, while chemical characterization of the obtained nanostructured surface was performed using energy dispersive spectroscopy (EDS). The surface modulus of elasticity and hardness before and after the surface nanostructure modification, was examined using the nanoindentation test, while the analysis of deformation and damage of the nanostructured surface after nanoindentation was performed using SEM. Cytotoxicity of the tested alloys and cell culture viability were assessed using the tetrazolium salt colorimetric test (MTT test) using mouse fibroblasts (L-929) and human lung fibroblasts (MRC-5) in liquid medium. Morphology and adhesion of cells on the surface were analysed using SEM. The obtained results indicate the strong influence of time, as a parameter of anodization, on the surface morphology. Influence of the HPT processing on the homogeneity of the nanostructured surface obtained by electrochemical anodization has also been shown. The alloys before and after the surface nanostructure modification are adequate in their biocompatibility for use in the implantology. Characterization of the titanium-based materials surface using nanoindentation showed a decrease in the values of modulus of elasticity and hardness for materials with nanostructured surface, which are close to the values of bone tissue in the human body.",
publisher = "Materials Research Society of Srebia",
journal = "Twenty-third Annual Conference YUCOMAT 2022 &
Twelfth World Round Table Conference on Sintering XII WRTCS",
title = "Nanostructured surface modification and characterization of titanium based materials for medical application",
pages = "154",
url = "https://hdl.handle.net/21.15107/rcub_technorep_5258"
}

Barjaktarević, D., Rakin, M., Veljović, Đ., Međo, B.,& Đokić, V.. (2022). Nanostructured surface modification and characterization of titanium based materials for medical application. in Twenty-third Annual Conference YUCOMAT 2022 &
Twelfth World Round Table Conference on Sintering XII WRTCS
Materials Research Society of Srebia., 154.
https://hdl.handle.net/21.15107/rcub_technorep_5258

Barjaktarević D, Rakin M, Veljović Đ, Međo B, Đokić V. Nanostructured surface modification and characterization of titanium based materials for medical application. in Twenty-third Annual Conference YUCOMAT 2022 &
Twelfth World Round Table Conference on Sintering XII WRTCS. 2022;:154.
https://hdl.handle.net/21.15107/rcub_technorep_5258 .

Barjaktarević, Dragana, Rakin, Marko, Veljović, Đorđe, Međo, Bojan, Đokić, Veljko, "Nanostructured surface modification and characterization of titanium based materials for medical application" in Twenty-third Annual Conference YUCOMAT 2022 &
Twelfth World Round Table Conference on Sintering XII WRTCS (2022):154,
https://hdl.handle.net/21.15107/rcub_technorep_5258 .

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  - CONF
AU  - Rakin, Marko
AU  - Barjaktarević, Dragana
AU  - Đokić, Veljko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6178
C3  - Virtual Event: Global Summit on Future of Materials Science and Research
T1  - Nanostructured surface modification of coarse-grained and ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application.
EP  - 30
SP  - 29
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6178
ER  - 

@conference{
author = "Rakin, Marko and Barjaktarević, Dragana and Đokić, Veljko",
year = "2021",
journal = "Virtual Event: Global Summit on Future of Materials Science and Research",
title = "Nanostructured surface modification of coarse-grained and ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application.",
pages = "30-29",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6178"
}

Rakin, M., Barjaktarević, D.,& Đokić, V.. (2021). Nanostructured surface modification of coarse-grained and ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application.. in Virtual Event: Global Summit on Future of Materials Science and Research, 29-30.
https://hdl.handle.net/21.15107/rcub_technorep_6178

Rakin M, Barjaktarević D, Đokić V. Nanostructured surface modification of coarse-grained and ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application.. in Virtual Event: Global Summit on Future of Materials Science and Research. 2021;:29-30.
https://hdl.handle.net/21.15107/rcub_technorep_6178 .

Rakin, Marko, Barjaktarević, Dragana, Đokić, Veljko, "Nanostructured surface modification of coarse-grained and ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application." in Virtual Event: Global Summit on Future of Materials Science and Research (2021):29-30,
https://hdl.handle.net/21.15107/rcub_technorep_6178 .

TY  - CONF
AU  - Laketić, Slađana
AU  - Rakin, Marko
AU  - Momčilović, Miloš
AU  - Ciganović, Jovan
AU  - Veljović, Đorđe
AU  - Cvijović-Alagić, Ivana
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6342
PB  - Faculty of Technology, University of Novi Sad
C3  - 14th EcerS Conference for Young Scientists in Ceramics, CYSC
T1  - Surface damage caused by laser irradiation of the Ti45Nb alloy processed by high-pressure torsion
SP  - 53
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6342
ER  - 

@conference{
author = "Laketić, Slađana and Rakin, Marko and Momčilović, Miloš and Ciganović, Jovan and Veljović, Đorđe and Cvijović-Alagić, Ivana",
year = "2021",
publisher = "Faculty of Technology, University of Novi Sad",
journal = "14th EcerS Conference for Young Scientists in Ceramics, CYSC",
title = "Surface damage caused by laser irradiation of the Ti45Nb alloy processed by high-pressure torsion",
pages = "53",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6342"
}

Laketić, S., Rakin, M., Momčilović, M., Ciganović, J., Veljović, Đ.,& Cvijović-Alagić, I.. (2021). Surface damage caused by laser irradiation of the Ti45Nb alloy processed by high-pressure torsion. in 14th EcerS Conference for Young Scientists in Ceramics, CYSC
Faculty of Technology, University of Novi Sad., 53.
https://hdl.handle.net/21.15107/rcub_technorep_6342

Laketić S, Rakin M, Momčilović M, Ciganović J, Veljović Đ, Cvijović-Alagić I. Surface damage caused by laser irradiation of the Ti45Nb alloy processed by high-pressure torsion. in 14th EcerS Conference for Young Scientists in Ceramics, CYSC. 2021;:53.
https://hdl.handle.net/21.15107/rcub_technorep_6342 .

Laketić, Slađana, Rakin, Marko, Momčilović, Miloš, Ciganović, Jovan, Veljović, Đorđe, Cvijović-Alagić, Ivana, "Surface damage caused by laser irradiation of the Ti45Nb alloy processed by high-pressure torsion" in 14th EcerS Conference for Young Scientists in Ceramics, CYSC (2021):53,
https://hdl.handle.net/21.15107/rcub_technorep_6342 .

TY  - PAT
AU  - Veljić, Darko
AU  - Bajić, Nikola
AU  - Rakin, Marko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6343
AB  - Prikazani pronalazak, alat od osam pari kalibrisanih valjaka za uzdužno kontinualno profilisanje uske čelične trake i formiranje punjene žice, se odnosi na konstrukciono rešenje alata za kalibraciju uske čelične trake i alata za formiranje punjene žice za izradu jezgra specijalne bazične elektrode za zavarivanje. To je alat koji poseduje 8 pari uzastopno postavljenih kalibrisanih valjaka, od kojih 5 pari kalibrisanih valjaka u kontinuitetu formira žleb duž uske čelične trake i 3 para kalibrisanih valjaka za zatvaranje u oblik cevi sa sučeonim podužnim spojem. Dobijena cev je prečnika 3,8mm i namenjena je za izradu punjene žice. Alat se ugrađuje na liniju za kalibraciju čelične trake i formiranje punjene žice. Dobijena punjena žica je namenjena za izradu jezgra specijalne bazične elektrode za zavarivanje čime se proširuje oblast tehnike u kome pronalazak ima značajnu primenu. Primena punjene žice za izradu jezgra elektrode omogućava kombinaciju rutilnog punjenja jezgra sa bazičnom oblogom elektrode, kao i mogućnost mikrolegiranja i legiranja metala šava preko jezgra elektrode.
T2  - Zavod za intelektualnu svojinu, sektor  za patente odeljenje za mašinstvo, elektrotehniku i opštu tehniku 990
T1  - Alat od osam pari kalibrisanih valljaka za uzdužno kontinualno profilisanje uske čelične trake i formiranje punjene žice
IS  - 021/13722-MP-2021/0085
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6343
ER  - 

@misc{
author = "Veljić, Darko and Bajić, Nikola and Rakin, Marko",
year = "2021",
abstract = "Prikazani pronalazak, alat od osam pari kalibrisanih valjaka za uzdužno kontinualno profilisanje uske čelične trake i formiranje punjene žice, se odnosi na konstrukciono rešenje alata za kalibraciju uske čelične trake i alata za formiranje punjene žice za izradu jezgra specijalne bazične elektrode za zavarivanje. To je alat koji poseduje 8 pari uzastopno postavljenih kalibrisanih valjaka, od kojih 5 pari kalibrisanih valjaka u kontinuitetu formira žleb duž uske čelične trake i 3 para kalibrisanih valjaka za zatvaranje u oblik cevi sa sučeonim podužnim spojem. Dobijena cev je prečnika 3,8mm i namenjena je za izradu punjene žice. Alat se ugrađuje na liniju za kalibraciju čelične trake i formiranje punjene žice. Dobijena punjena žica je namenjena za izradu jezgra specijalne bazične elektrode za zavarivanje čime se proširuje oblast tehnike u kome pronalazak ima značajnu primenu. Primena punjene žice za izradu jezgra elektrode omogućava kombinaciju rutilnog punjenja jezgra sa bazičnom oblogom elektrode, kao i mogućnost mikrolegiranja i legiranja metala šava preko jezgra elektrode.",
journal = "Zavod za intelektualnu svojinu, sektor  za patente odeljenje za mašinstvo, elektrotehniku i opštu tehniku 990",
title = "Alat od osam pari kalibrisanih valljaka za uzdužno kontinualno profilisanje uske čelične trake i formiranje punjene žice",
number = "021/13722-MP-2021/0085",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6343"
}

Veljić, D., Bajić, N.,& Rakin, M.. (2021). Alat od osam pari kalibrisanih valljaka za uzdužno kontinualno profilisanje uske čelične trake i formiranje punjene žice. in Zavod za intelektualnu svojinu, sektor  za patente odeljenje za mašinstvo, elektrotehniku i opštu tehniku 990(021/13722-MP-2021/0085).
https://hdl.handle.net/21.15107/rcub_technorep_6343

Veljić D, Bajić N, Rakin M. Alat od osam pari kalibrisanih valljaka za uzdužno kontinualno profilisanje uske čelične trake i formiranje punjene žice. in Zavod za intelektualnu svojinu, sektor  za patente odeljenje za mašinstvo, elektrotehniku i opštu tehniku 990. 2021;(021/13722-MP-2021/0085).
https://hdl.handle.net/21.15107/rcub_technorep_6343 .

Veljić, Darko, Bajić, Nikola, Rakin, Marko, "Alat od osam pari kalibrisanih valljaka za uzdužno kontinualno profilisanje uske čelične trake i formiranje punjene žice" in Zavod za intelektualnu svojinu, sektor  za patente odeljenje za mašinstvo, elektrotehniku i opštu tehniku 990, no. 021/13722-MP-2021/0085 (2021),
https://hdl.handle.net/21.15107/rcub_technorep_6343 .