TY  - JOUR
AU  - Cvijović-Alagić, Ivana
AU  - Laketic, S.
AU  - Bajat, Jelena
AU  - Hohenwarter, A.
AU  - Rakin, Marko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4774
AB  - In this study, the influence of microstructural refinement induced by the high-pressure torsion (HPT) on the corrosion resistance of the Ti-45Nb (mass%) alloy was investigated. The alloy characteristics before and after the HPT deformation were analyzed by electron backscatter diffraction (EBSD), scanning transmission electron microscopy (STEM), x-ray diffraction (XRD), and Vickers microhardness measurements, while the alloy corrosion behavior in simulated physiological conditions was examined by potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS) analysis. Detailed microstructural analyses revealed that the HPT deformation led to significant grain refinement of the Ti-45Nb alloy exhibiting an ultra-fine grained (UFG) microstructure along with a substantial increase of hardness. Results also indicated that the grain refinement did not affect the alloy phase composition since beta-Ti and Ti4Nb phases were present in the microstructure before and after the HPT deformation. Even though the Ti-45Nb alloy in both, coarse-grained (CG) and UFG, conditions shows high corrosion resistance in Ringer's solution at 37 degrees C, it was observed that the HPT treatment additionally improved the alloy corrosion properties. Namely, more rapid formation of the passivating layer with better barrier properties on the UFG alloy surface was recorded and resulted in better corrosion resistance of the alloy after HPT deformation. An increase of the grain contact area in the refined microstructure caused an increase of the diffusive transfer along the grain boundaries, accelerated the formation of a less defective protective barrier surface layer, and promoted the alloy surface passivation in the simulated physiological conditions.
T2  - Surface & Coatings Technology
T1  - Grain refinement effect on the Ti-45Nb alloy electrochemical behavior in simulated physiological solution
VL  - 423
DO  - 10.1016/j.surfcoat.2021.127609
ER  - 

@article{
author = "Cvijović-Alagić, Ivana and Laketic, S. and Bajat, Jelena and Hohenwarter, A. and Rakin, Marko",
year = "2021",
abstract = "In this study, the influence of microstructural refinement induced by the high-pressure torsion (HPT) on the corrosion resistance of the Ti-45Nb (mass%) alloy was investigated. The alloy characteristics before and after the HPT deformation were analyzed by electron backscatter diffraction (EBSD), scanning transmission electron microscopy (STEM), x-ray diffraction (XRD), and Vickers microhardness measurements, while the alloy corrosion behavior in simulated physiological conditions was examined by potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS) analysis. Detailed microstructural analyses revealed that the HPT deformation led to significant grain refinement of the Ti-45Nb alloy exhibiting an ultra-fine grained (UFG) microstructure along with a substantial increase of hardness. Results also indicated that the grain refinement did not affect the alloy phase composition since beta-Ti and Ti4Nb phases were present in the microstructure before and after the HPT deformation. Even though the Ti-45Nb alloy in both, coarse-grained (CG) and UFG, conditions shows high corrosion resistance in Ringer's solution at 37 degrees C, it was observed that the HPT treatment additionally improved the alloy corrosion properties. Namely, more rapid formation of the passivating layer with better barrier properties on the UFG alloy surface was recorded and resulted in better corrosion resistance of the alloy after HPT deformation. An increase of the grain contact area in the refined microstructure caused an increase of the diffusive transfer along the grain boundaries, accelerated the formation of a less defective protective barrier surface layer, and promoted the alloy surface passivation in the simulated physiological conditions.",
journal = "Surface & Coatings Technology",
title = "Grain refinement effect on the Ti-45Nb alloy electrochemical behavior in simulated physiological solution",
volume = "423",
doi = "10.1016/j.surfcoat.2021.127609"
}

Cvijović-Alagić, I., Laketic, S., Bajat, J., Hohenwarter, A.,& Rakin, M.. (2021). Grain refinement effect on the Ti-45Nb alloy electrochemical behavior in simulated physiological solution. in Surface & Coatings Technology, 423.
https://doi.org/10.1016/j.surfcoat.2021.127609

Cvijović-Alagić I, Laketic S, Bajat J, Hohenwarter A, Rakin M. Grain refinement effect on the Ti-45Nb alloy electrochemical behavior in simulated physiological solution. in Surface & Coatings Technology. 2021;423.
doi:10.1016/j.surfcoat.2021.127609 .

Cvijović-Alagić, Ivana, Laketic, S., Bajat, Jelena, Hohenwarter, A., Rakin, Marko, "Grain refinement effect on the Ti-45Nb alloy electrochemical behavior in simulated physiological solution" in Surface & Coatings Technology, 423 (2021),
https://doi.org/10.1016/j.surfcoat.2021.127609 . .

TY  - JOUR
AU  - Laketic, S.
AU  - Rakin, Marko
AU  - Momcilovic, M.
AU  - Ciganovic, J.
AU  - Veljović, Đorđe
AU  - Cvijović-Alagić, Ivana
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4918
AB  - In the present study surface alterations of the high pressure torsion (HPT)-deformed Ti-45Nb (mass%) alloy induced by laser irradiation treatment are presented. The alloy was irradiated in air, argon, and nitrogen atmosphere using the Nd:YAG laser. Laser-induced surface modifications were analyzed by field-emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS), profilometric analysis, and Vickers microhardness measurements. Alloy irradiation under a low laser output energy and a low number of accumulated pulses resulted in the formation of shallow surface craters. An increase of these irradiation parameters caused the appearance of more pronounced surface craters with microcracks and hydrodynamic effects in the form of wave-like structures, ripples, and solidified droplets and consequently caused an increase in the surface roughness. The highest value of the surface roughness of 3.062 Im was attained during the alloy irradiation in argon atmosphere under 15 mJ with 150 accumulated pulses. Interaction of the laser beam with the alloy surface was accompanied by plasma formation and surface ablation due to the irradiation energy absorption. The maximal ablated target material volumes of 5.5 x 10(14) nm(3) and 2.6 x 10(14) nm(3) were observed after the irradiation under 15 mJ with 150 accumulated pulses in argon and air atmosphere, respectively. Moreover, attainment of high temperatures at the alloy surface induced its chemical composition alterations. Formation of mixed Ti- and Nb-oxide surface film and absence of nitride particles at the alloy surface was detected irrespective of the irradiation atmosphere. Irradiation in air resulted in the appearance of the most pronounced surface oxide layer with the highest microhardness value which can in great merit influence an increase of the alloy bio-integration abilities and its tribo-corrosion resistance.
T2  - Surface & Coatings Technology
T1  - Influence of laser irradiation parameters on the ultrafine-grained Ti-45Nb alloy surface characteristics
VL  - 418
DO  - 10.1016/j.surfcoat.2021.127255
ER  - 

@article{
author = "Laketic, S. and Rakin, Marko and Momcilovic, M. and Ciganovic, J. and Veljović, Đorđe and Cvijović-Alagić, Ivana",
year = "2021",
abstract = "In the present study surface alterations of the high pressure torsion (HPT)-deformed Ti-45Nb (mass%) alloy induced by laser irradiation treatment are presented. The alloy was irradiated in air, argon, and nitrogen atmosphere using the Nd:YAG laser. Laser-induced surface modifications were analyzed by field-emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS), profilometric analysis, and Vickers microhardness measurements. Alloy irradiation under a low laser output energy and a low number of accumulated pulses resulted in the formation of shallow surface craters. An increase of these irradiation parameters caused the appearance of more pronounced surface craters with microcracks and hydrodynamic effects in the form of wave-like structures, ripples, and solidified droplets and consequently caused an increase in the surface roughness. The highest value of the surface roughness of 3.062 Im was attained during the alloy irradiation in argon atmosphere under 15 mJ with 150 accumulated pulses. Interaction of the laser beam with the alloy surface was accompanied by plasma formation and surface ablation due to the irradiation energy absorption. The maximal ablated target material volumes of 5.5 x 10(14) nm(3) and 2.6 x 10(14) nm(3) were observed after the irradiation under 15 mJ with 150 accumulated pulses in argon and air atmosphere, respectively. Moreover, attainment of high temperatures at the alloy surface induced its chemical composition alterations. Formation of mixed Ti- and Nb-oxide surface film and absence of nitride particles at the alloy surface was detected irrespective of the irradiation atmosphere. Irradiation in air resulted in the appearance of the most pronounced surface oxide layer with the highest microhardness value which can in great merit influence an increase of the alloy bio-integration abilities and its tribo-corrosion resistance.",
journal = "Surface & Coatings Technology",
title = "Influence of laser irradiation parameters on the ultrafine-grained Ti-45Nb alloy surface characteristics",
volume = "418",
doi = "10.1016/j.surfcoat.2021.127255"
}

Laketic, S., Rakin, M., Momcilovic, M., Ciganovic, J., Veljović, Đ.,& Cvijović-Alagić, I.. (2021). Influence of laser irradiation parameters on the ultrafine-grained Ti-45Nb alloy surface characteristics. in Surface & Coatings Technology, 418.
https://doi.org/10.1016/j.surfcoat.2021.127255

Laketic S, Rakin M, Momcilovic M, Ciganovic J, Veljović Đ, Cvijović-Alagić I. Influence of laser irradiation parameters on the ultrafine-grained Ti-45Nb alloy surface characteristics. in Surface & Coatings Technology. 2021;418.
doi:10.1016/j.surfcoat.2021.127255 .

Laketic, S., Rakin, Marko, Momcilovic, M., Ciganovic, J., Veljović, Đorđe, Cvijović-Alagić, Ivana, "Influence of laser irradiation parameters on the ultrafine-grained Ti-45Nb alloy surface characteristics" in Surface & Coatings Technology, 418 (2021),
https://doi.org/10.1016/j.surfcoat.2021.127255 . .