TY  - CHAP
AU  - Barjaktarević, Dragana
AU  - Međo, Bojan
AU  - Đokić, Veljko
AU  - Rakin, Marko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5252
AB  - Lower value of modulus of elasticity, closer to that of a bone, is one of the crucial surface properties in accepting the implant material from the surrounding tissue, and reduces the possibility of slow disappearance of bone in contact with the implant. In the present study, ultrafine-grained (UFG) Ti-13Nb-13Zr alloy was obtained using high pressure torsion process (HPT) under a pressure of 4.1 GPa with a rotational speed of 0.2 rpm up to 5 rotations at room temperature. Nanostructured surface on coarse-grained (CG) and UFG Ti-13Nb-13Zr alloy was formed using electrochemical anodization in the 1M H3PO4 + NaF electrolyte, during 60 and 90 minutes. Scanning electron microscopy (SEM) was used to characterise the morphology of the surface, while nanomechanical properties of the surface, modulus of elasticity and nanohardness were determined using the nanoindentation test. Also, in order to characterise deformation of the nanotubes after nanoindentation test, SEM was done. It was shown that the nanotubular oxide layer was formed as result of the electrochemical anodization process during both anodizing times. The surface of anodized alloys has lower modulus of elasticity than surface of non-anodized ones. Anodized UFG alloy had the lowest modulus of elasticity of the surface when compared to other tested samples, which makes it more acceptable for biomedical usage.
PB  - Springer
T2  - Proceedings of the International Conference
of Experimental and Numerical Investigations
and New Technologies
T1  - Morphology and nanomechanical properties of the ultrafine-grained Ti-13Nb-13Zr alloy surface obtained using electrochemical anodization
EP  - 141
SP  - 123
VL  - 323
DO  - 10.1007/978-3-030-86009-7_7
ER  - 

@inbook{
author = "Barjaktarević, Dragana and Međo, Bojan and Đokić, Veljko and Rakin, Marko",
year = "2021",
abstract = "Lower value of modulus of elasticity, closer to that of a bone, is one of the crucial surface properties in accepting the implant material from the surrounding tissue, and reduces the possibility of slow disappearance of bone in contact with the implant. In the present study, ultrafine-grained (UFG) Ti-13Nb-13Zr alloy was obtained using high pressure torsion process (HPT) under a pressure of 4.1 GPa with a rotational speed of 0.2 rpm up to 5 rotations at room temperature. Nanostructured surface on coarse-grained (CG) and UFG Ti-13Nb-13Zr alloy was formed using electrochemical anodization in the 1M H3PO4 + NaF electrolyte, during 60 and 90 minutes. Scanning electron microscopy (SEM) was used to characterise the morphology of the surface, while nanomechanical properties of the surface, modulus of elasticity and nanohardness were determined using the nanoindentation test. Also, in order to characterise deformation of the nanotubes after nanoindentation test, SEM was done. It was shown that the nanotubular oxide layer was formed as result of the electrochemical anodization process during both anodizing times. The surface of anodized alloys has lower modulus of elasticity than surface of non-anodized ones. Anodized UFG alloy had the lowest modulus of elasticity of the surface when compared to other tested samples, which makes it more acceptable for biomedical usage.",
publisher = "Springer",
journal = "Proceedings of the International Conference
of Experimental and Numerical Investigations
and New Technologies",
booktitle = "Morphology and nanomechanical properties of the ultrafine-grained Ti-13Nb-13Zr alloy surface obtained using electrochemical anodization",
pages = "141-123",
volume = "323",
doi = "10.1007/978-3-030-86009-7_7"
}

Barjaktarević, D., Međo, B., Đokić, V.,& Rakin, M.. (2021). Morphology and nanomechanical properties of the ultrafine-grained Ti-13Nb-13Zr alloy surface obtained using electrochemical anodization. in Proceedings of the International Conference
of Experimental and Numerical Investigations
and New Technologies
Springer., 323, 123-141.
https://doi.org/10.1007/978-3-030-86009-7_7

Barjaktarević D, Međo B, Đokić V, Rakin M. Morphology and nanomechanical properties of the ultrafine-grained Ti-13Nb-13Zr alloy surface obtained using electrochemical anodization. in Proceedings of the International Conference
of Experimental and Numerical Investigations
and New Technologies. 2021;323:123-141.
doi:10.1007/978-3-030-86009-7_7 .

Barjaktarević, Dragana, Međo, Bojan, Đokić, Veljko, Rakin, Marko, "Morphology and nanomechanical properties of the ultrafine-grained Ti-13Nb-13Zr alloy surface obtained using electrochemical anodization" in Proceedings of the International Conference
of Experimental and Numerical Investigations
and New Technologies, 323 (2021):123-141,
https://doi.org/10.1007/978-3-030-86009-7_7 . .

TY  - CONF
AU  - Barjaktarević, Dragana
AU  - Đokić, Veljko
AU  - Stevanović, Sanja
AU  - Rakin, Marko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5253
AB  - Surface roughness is one of the influencing factors on the friction and wear mechanism of metallic materials. However, surface roughness of metallic biomaterials plays a major role in assessing the biocompatibility and adhesion of human cells of the surrounding bone tissue on the biomaterials surface. Namely, it is already known that as the surface roughness increases, contact surface with human cells increases, and thus their adhesion to the surface. In order to achieve adequate roughness and biocompatibility, it is often necessary to additionally subject the surface of the biomaterial to modification. 
In the present study, nanostructured oxide coating on the Ti-13Nb-13Zr alloy was formed by electrochemical anodization in the 1M H3PO4 + NaF electrolyte, during 60, 90, 120 minutes. The scanning electron microscopy (SEM) was used to analyse the nanostructured oxide coating morphology and showed that highly ordered nanotubular oxide layers were formed by electrochemical anodization. The atomic force microscopy (AFM) was used to characterise the surface topography before and after electrochemical anodization. Results showed that the surface had higher roughness after electrochemical anodization compared to initial surface of the alloy. It was also shown that increase of anodizing time induces increase of the surface roughness.
PB  - Univerzitet u Beogradu, Mašinski fakultet
C3  - Proceedings of Balkantrib '20, 10th Intenational Conference on Tribology
T1  - Influence of the electrochemical anodization on the surface roughness of Ti-13Nb-13Zr medical alloy
EP  - 62
SP  - 59
UR  - https://hdl.handle.net/21.15107/rcub_technorep_5253
ER  - 

@conference{
author = "Barjaktarević, Dragana and Đokić, Veljko and Stevanović, Sanja and Rakin, Marko",
year = "2021",
abstract = "Surface roughness is one of the influencing factors on the friction and wear mechanism of metallic materials. However, surface roughness of metallic biomaterials plays a major role in assessing the biocompatibility and adhesion of human cells of the surrounding bone tissue on the biomaterials surface. Namely, it is already known that as the surface roughness increases, contact surface with human cells increases, and thus their adhesion to the surface. In order to achieve adequate roughness and biocompatibility, it is often necessary to additionally subject the surface of the biomaterial to modification. 
In the present study, nanostructured oxide coating on the Ti-13Nb-13Zr alloy was formed by electrochemical anodization in the 1M H3PO4 + NaF electrolyte, during 60, 90, 120 minutes. The scanning electron microscopy (SEM) was used to analyse the nanostructured oxide coating morphology and showed that highly ordered nanotubular oxide layers were formed by electrochemical anodization. The atomic force microscopy (AFM) was used to characterise the surface topography before and after electrochemical anodization. Results showed that the surface had higher roughness after electrochemical anodization compared to initial surface of the alloy. It was also shown that increase of anodizing time induces increase of the surface roughness.",
publisher = "Univerzitet u Beogradu, Mašinski fakultet",
journal = "Proceedings of Balkantrib '20, 10th Intenational Conference on Tribology",
title = "Influence of the electrochemical anodization on the surface roughness of Ti-13Nb-13Zr medical alloy",
pages = "62-59",
url = "https://hdl.handle.net/21.15107/rcub_technorep_5253"
}

Barjaktarević, D., Đokić, V., Stevanović, S.,& Rakin, M.. (2021). Influence of the electrochemical anodization on the surface roughness of Ti-13Nb-13Zr medical alloy. in Proceedings of Balkantrib '20, 10th Intenational Conference on Tribology
Univerzitet u Beogradu, Mašinski fakultet., 59-62.
https://hdl.handle.net/21.15107/rcub_technorep_5253

Barjaktarević D, Đokić V, Stevanović S, Rakin M. Influence of the electrochemical anodization on the surface roughness of Ti-13Nb-13Zr medical alloy. in Proceedings of Balkantrib '20, 10th Intenational Conference on Tribology. 2021;:59-62.
https://hdl.handle.net/21.15107/rcub_technorep_5253 .

Barjaktarević, Dragana, Đokić, Veljko, Stevanović, Sanja, Rakin, Marko, "Influence of the electrochemical anodization on the surface roughness of Ti-13Nb-13Zr medical alloy" in Proceedings of Balkantrib '20, 10th Intenational Conference on Tribology (2021):59-62,
https://hdl.handle.net/21.15107/rcub_technorep_5253 .

TY  - CONF
AU  - Barjaktarević, Dragana
AU  - Đokić, Veljko
AU  - Veljović, Đorđe
AU  - Rakin, Marko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5257
PB  - Materials Research Society of Srebia
C3  - Materials Research Society of Srebia
T1  - Morphology and mechanical properties of the nanotubular oxide coating formed on the ultrafine-grained Ti-13Nb-13Zr alloy
SP  - 79
UR  - https://hdl.handle.net/21.15107/rcub_technorep_5257
ER  - 

@conference{
author = "Barjaktarević, Dragana and Đokić, Veljko and Veljović, Đorđe and Rakin, Marko",
year = "2021",
publisher = "Materials Research Society of Srebia",
journal = "Materials Research Society of Srebia",
title = "Morphology and mechanical properties of the nanotubular oxide coating formed on the ultrafine-grained Ti-13Nb-13Zr alloy",
pages = "79",
url = "https://hdl.handle.net/21.15107/rcub_technorep_5257"
}

Barjaktarević, D., Đokić, V., Veljović, Đ.,& Rakin, M.. (2021). Morphology and mechanical properties of the nanotubular oxide coating formed on the ultrafine-grained Ti-13Nb-13Zr alloy. in Materials Research Society of Srebia
Materials Research Society of Srebia., 79.
https://hdl.handle.net/21.15107/rcub_technorep_5257

Barjaktarević D, Đokić V, Veljović Đ, Rakin M. Morphology and mechanical properties of the nanotubular oxide coating formed on the ultrafine-grained Ti-13Nb-13Zr alloy. in Materials Research Society of Srebia. 2021;:79.
https://hdl.handle.net/21.15107/rcub_technorep_5257 .

Barjaktarević, Dragana, Đokić, Veljko, Veljović, Đorđe, Rakin, Marko, "Morphology and mechanical properties of the nanotubular oxide coating formed on the ultrafine-grained Ti-13Nb-13Zr alloy" in Materials Research Society of Srebia (2021):79,
https://hdl.handle.net/21.15107/rcub_technorep_5257 .

TY  - CONF
AU  - Barjaktarević, Dragana
AU  - Međo, Bojan
AU  - Đokić, Veljko
AU  - Rakin, Marko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5259
AB  - Anodized surface on coarse-grained (CG) and ultrafine-grained (UFG) Ti-13Nb-13Zr alloy was obtained using electrochemical surface modification in the 1M H3PO4 + NaF electrolyte. Scanning electron microscopy (SEM) was used to characterise the microstructure of anodized surface, while mechanical surface properties were determined from the nanoindentation test. Numerical analysis of deformation of oxide film exposed to nanoindentation is performed on simplified 2D finite element models, with the main aim to determine the influence of the dimensions of the nanotubes on resistance to external loading. Software package Simulia Abaqus is used. It was shown that the homogeneous oxide film was formed at longer time period, while inhomogeneous oxide film was formed at shorter time period, for both materials. The oxide film was composed of nanotubes, whose deformation after the nanoindentation test is characterized by SEM. The surface of anodized alloys has lower mechanical surface properties (modulus of elasticity and nanohardness) than surface of non-anodized ones, which make them more acceptable for biomedical usage. Numerical calculations revealed the influence of morphology of the anodized surface layer on its load carrying capacity
PB  - Innovation Center of Faculty of Mechanical Engineering, Belgrade
C3  - International Conference of Exsperimental and Numerical Investigations and New Technologies
T1  - Microstructure and mechanical properties of anodized surface of ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application
SP  - 36
UR  - https://hdl.handle.net/21.15107/rcub_technorep_5259
ER  - 

@conference{
author = "Barjaktarević, Dragana and Međo, Bojan and Đokić, Veljko and Rakin, Marko",
year = "2021",
abstract = "Anodized surface on coarse-grained (CG) and ultrafine-grained (UFG) Ti-13Nb-13Zr alloy was obtained using electrochemical surface modification in the 1M H3PO4 + NaF electrolyte. Scanning electron microscopy (SEM) was used to characterise the microstructure of anodized surface, while mechanical surface properties were determined from the nanoindentation test. Numerical analysis of deformation of oxide film exposed to nanoindentation is performed on simplified 2D finite element models, with the main aim to determine the influence of the dimensions of the nanotubes on resistance to external loading. Software package Simulia Abaqus is used. It was shown that the homogeneous oxide film was formed at longer time period, while inhomogeneous oxide film was formed at shorter time period, for both materials. The oxide film was composed of nanotubes, whose deformation after the nanoindentation test is characterized by SEM. The surface of anodized alloys has lower mechanical surface properties (modulus of elasticity and nanohardness) than surface of non-anodized ones, which make them more acceptable for biomedical usage. Numerical calculations revealed the influence of morphology of the anodized surface layer on its load carrying capacity",
publisher = "Innovation Center of Faculty of Mechanical Engineering, Belgrade",
journal = "International Conference of Exsperimental and Numerical Investigations and New Technologies",
title = "Microstructure and mechanical properties of anodized surface of ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application",
pages = "36",
url = "https://hdl.handle.net/21.15107/rcub_technorep_5259"
}

Barjaktarević, D., Međo, B., Đokić, V.,& Rakin, M.. (2021). Microstructure and mechanical properties of anodized surface of ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application. in International Conference of Exsperimental and Numerical Investigations and New Technologies
Innovation Center of Faculty of Mechanical Engineering, Belgrade., 36.
https://hdl.handle.net/21.15107/rcub_technorep_5259

Barjaktarević D, Međo B, Đokić V, Rakin M. Microstructure and mechanical properties of anodized surface of ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application. in International Conference of Exsperimental and Numerical Investigations and New Technologies. 2021;:36.
https://hdl.handle.net/21.15107/rcub_technorep_5259 .

Barjaktarević, Dragana, Međo, Bojan, Đokić, Veljko, Rakin, Marko, "Microstructure and mechanical properties of anodized surface of ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application" in International Conference of Exsperimental and Numerical Investigations and New Technologies (2021):36,
https://hdl.handle.net/21.15107/rcub_technorep_5259 .