TY  - JOUR
AU  - Cvijović-Alagić, Ivana
AU  - Cvijović, Zorica M.
AU  - Zagorac, Dejan
AU  - Jovanović, Milan T.
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5884
AB  - The microstructure variation and oxidation behavior of a hot-rolled and quenched Ti-24Al-11Nb (at%) intermetallic alloy with and without protective Ni-20Cr (at%) coating were studied in the air at a cyclic annealing temperature of 600 °C and 900 °C. The phase transformations monitored up to 120 h of alloy oxidation and oxidation products were examined using different experimental techniques. The oxidation kinetics was determined by recording the mass gain vs. time data and oxidation activation energy was evaluated. It was found that the annealing temperature and deposited coating significantly affect the scale formation and growth. The alloy showed better oxidation resistance at 600 °C, irrespective of the protective coating application. The higher temperature promoted the formation of thicker and multi-layered scale predominantly composed of Nb-doped TiO2 and Al2O3 oxides, which cracked and spalled causing oxidation rate for an order of magnitude higher than that at 600 °C. The presence of AlN decelerated the oxide scale growth, which obeyed a parabolic rate law. It was also noted that a two-phase α2+β microstructure changed to a greater extent. With increasing temperature, the α2→β phase transformation occurred more intensive and new α2′′ and O-Ti2AlNb phase appeared. The Ni-20Cr coating reduced the oxidation rate at both temperatures and improved the scale-spallation resistance. The compact Cr2O3 layer formed on the coated alloy led to the preferential Al2O3 formation, increasing its amount in mixture with Nb-enriched TiO2 oxide. Thin TiN layer detected beneath the oxide scale also supported the formation of slow-growing Al2O3, leading to a decrease in the oxidation rate. The external scale suppression contributed to the greater diffusion zone enrichment, resulting in the faster O-Ti2AlNb formation. The experimentally observed O-Ti2AlNb formation was confirmed by ab initio modeling. Furthermore, additional structures were predicted and studied using first-principles calculations in the O-Ti2AlNb compound. © 2018
T2  - Ceramics International
T1  - Cyclic oxidation of Ti3Al-based materials
EP  - 9438
IS  - 7
SP  - 9423
VL  - 45
DO  - 10.1016/j.ceramint.2018.08.287
ER  - 

@article{
author = "Cvijović-Alagić, Ivana and Cvijović, Zorica M. and Zagorac, Dejan and Jovanović, Milan T.",
year = "2019",
abstract = "The microstructure variation and oxidation behavior of a hot-rolled and quenched Ti-24Al-11Nb (at%) intermetallic alloy with and without protective Ni-20Cr (at%) coating were studied in the air at a cyclic annealing temperature of 600 °C and 900 °C. The phase transformations monitored up to 120 h of alloy oxidation and oxidation products were examined using different experimental techniques. The oxidation kinetics was determined by recording the mass gain vs. time data and oxidation activation energy was evaluated. It was found that the annealing temperature and deposited coating significantly affect the scale formation and growth. The alloy showed better oxidation resistance at 600 °C, irrespective of the protective coating application. The higher temperature promoted the formation of thicker and multi-layered scale predominantly composed of Nb-doped TiO2 and Al2O3 oxides, which cracked and spalled causing oxidation rate for an order of magnitude higher than that at 600 °C. The presence of AlN decelerated the oxide scale growth, which obeyed a parabolic rate law. It was also noted that a two-phase α2+β microstructure changed to a greater extent. With increasing temperature, the α2→β phase transformation occurred more intensive and new α2′′ and O-Ti2AlNb phase appeared. The Ni-20Cr coating reduced the oxidation rate at both temperatures and improved the scale-spallation resistance. The compact Cr2O3 layer formed on the coated alloy led to the preferential Al2O3 formation, increasing its amount in mixture with Nb-enriched TiO2 oxide. Thin TiN layer detected beneath the oxide scale also supported the formation of slow-growing Al2O3, leading to a decrease in the oxidation rate. The external scale suppression contributed to the greater diffusion zone enrichment, resulting in the faster O-Ti2AlNb formation. The experimentally observed O-Ti2AlNb formation was confirmed by ab initio modeling. Furthermore, additional structures were predicted and studied using first-principles calculations in the O-Ti2AlNb compound. © 2018",
journal = "Ceramics International",
title = "Cyclic oxidation of Ti3Al-based materials",
pages = "9438-9423",
number = "7",
volume = "45",
doi = "10.1016/j.ceramint.2018.08.287"
}

Cvijović-Alagić, I., Cvijović, Z. M., Zagorac, D.,& Jovanović, M. T.. (2019). Cyclic oxidation of Ti3Al-based materials. in Ceramics International, 45(7), 9423-9438.
https://doi.org/10.1016/j.ceramint.2018.08.287

Cvijović-Alagić I, Cvijović ZM, Zagorac D, Jovanović MT. Cyclic oxidation of Ti3Al-based materials. in Ceramics International. 2019;45(7):9423-9438.
doi:10.1016/j.ceramint.2018.08.287 .

Cvijović-Alagić, Ivana, Cvijović, Zorica M., Zagorac, Dejan, Jovanović, Milan T., "Cyclic oxidation of Ti3Al-based materials" in Ceramics International, 45, no. 7 (2019):9423-9438,
https://doi.org/10.1016/j.ceramint.2018.08.287 . .

TY  - CONF
AU  - Cvijović-Alagić, Ivana
AU  - Međo, Bojan
AU  - Cvijović, Zorica
AU  - Gubeljak, Nenad
AU  - Rakin, Marko
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6298
AB  - The fracture behavior of implant Ti-6Al-4V alloy is essential for its service capability in orthopedic surgery. Therefore, it is
very important to understand and predict the fracture resistance of this biomedical material. Although several
micromechanical models have been developed for modeling the fracture behavior of metallic materials with ductile dimple
fracture as predominant fracture mode, they have predominantly been applied to materials such as steels and aluminum
alloys. Recently, efforts have been made to apply these micromechanical models to predict crack initiation and growth in
two-phase titanium alloys. Due to the complex multiple fracture micromechanisms operative in these alloys, it is necessary
to check the applicability of damage models on these materials. In the present study, the mechanical testing and numerical
simulation are carried out to characterize the fracture behavior of an extra-low impurity (ELI) Ti-6Al-4V alloy solution
treated below β transus temperature followed by water quenching in order to obtain the globular microstructure with 82
vol.% primary α and 18 vol.% β phase. The compact tension (CT) specimen is used for fracture testing. The crack tip
opening displacement (CTOD) and strain distribution near the crack tip are measured on its surface by the digital
stereometric method. The complete Gurson model (CGM) implemented in a finite element (FE) code ABAQUS is applied to
predict the crack resistance (CTOD-R) curves and crack growth initiation (CTODi) values. A relatively good correlation
between the experimental and results obtained by numerical simulation demonstrates the applicability of CGM for the
prediction of fracture behavior in Ti-6Al-4V ELI alloy with given microstructure. The better agreement, in comparison with
plane strain conditions, is achieved through a 3D ½ symmetrical FE model with appropriate FE size. The microstructural
effects on the fracture mechanics parameter and fracture modeling are discussed.
PB  - The Society for Structural Integrity and Life
C3  - 22nd European Conference on Fracture - ECF22
T1  - Numerical simulation of fracture in Ti-6Al-4V alloy for orthopedic applications,
SP  - 392
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6298
ER  - 

@conference{
author = "Cvijović-Alagić, Ivana and Međo, Bojan and Cvijović, Zorica and Gubeljak, Nenad and Rakin, Marko",
year = "2018",
abstract = "The fracture behavior of implant Ti-6Al-4V alloy is essential for its service capability in orthopedic surgery. Therefore, it is
very important to understand and predict the fracture resistance of this biomedical material. Although several
micromechanical models have been developed for modeling the fracture behavior of metallic materials with ductile dimple
fracture as predominant fracture mode, they have predominantly been applied to materials such as steels and aluminum
alloys. Recently, efforts have been made to apply these micromechanical models to predict crack initiation and growth in
two-phase titanium alloys. Due to the complex multiple fracture micromechanisms operative in these alloys, it is necessary
to check the applicability of damage models on these materials. In the present study, the mechanical testing and numerical
simulation are carried out to characterize the fracture behavior of an extra-low impurity (ELI) Ti-6Al-4V alloy solution
treated below β transus temperature followed by water quenching in order to obtain the globular microstructure with 82
vol.% primary α and 18 vol.% β phase. The compact tension (CT) specimen is used for fracture testing. The crack tip
opening displacement (CTOD) and strain distribution near the crack tip are measured on its surface by the digital
stereometric method. The complete Gurson model (CGM) implemented in a finite element (FE) code ABAQUS is applied to
predict the crack resistance (CTOD-R) curves and crack growth initiation (CTODi) values. A relatively good correlation
between the experimental and results obtained by numerical simulation demonstrates the applicability of CGM for the
prediction of fracture behavior in Ti-6Al-4V ELI alloy with given microstructure. The better agreement, in comparison with
plane strain conditions, is achieved through a 3D ½ symmetrical FE model with appropriate FE size. The microstructural
effects on the fracture mechanics parameter and fracture modeling are discussed.",
publisher = "The Society for Structural Integrity and Life",
journal = "22nd European Conference on Fracture - ECF22",
title = "Numerical simulation of fracture in Ti-6Al-4V alloy for orthopedic applications,",
pages = "392",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6298"
}

Cvijović-Alagić, I., Međo, B., Cvijović, Z., Gubeljak, N.,& Rakin, M.. (2018). Numerical simulation of fracture in Ti-6Al-4V alloy for orthopedic applications,. in 22nd European Conference on Fracture - ECF22
The Society for Structural Integrity and Life., 392.
https://hdl.handle.net/21.15107/rcub_technorep_6298

Cvijović-Alagić I, Međo B, Cvijović Z, Gubeljak N, Rakin M. Numerical simulation of fracture in Ti-6Al-4V alloy for orthopedic applications,. in 22nd European Conference on Fracture - ECF22. 2018;:392.
https://hdl.handle.net/21.15107/rcub_technorep_6298 .

Cvijović-Alagić, Ivana, Međo, Bojan, Cvijović, Zorica, Gubeljak, Nenad, Rakin, Marko, "Numerical simulation of fracture in Ti-6Al-4V alloy for orthopedic applications," in 22nd European Conference on Fracture - ECF22 (2018):392,
https://hdl.handle.net/21.15107/rcub_technorep_6298 .

TY  - JOUR
AU  - Vratnica, M.
AU  - Pluvinage, G.
AU  - Jodin, P.
AU  - Cvijović, Zorica
AU  - Rakin, M.
AU  - Burzić, Z.
PY  - 2010
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5602
AB  - The influence of notch radius on the fracture behavior of two high-strength Al-Zn-Mg-Cu alloys with different Fe content in the T73 condition was investigated. The fracture toughness tests were performed on non-fatigue-precracked notched bending specimens with different notch radii ranged from 0.15 mm to 1.0 mm. The obtained data were interpreted using the concept of Notch Fracture Mechanics combined with finite-element method (FEM) calculations. It was found that both alloys are very sensitive to the notch radius. The fracture toughness increases with increasing notch radius. For a given notch radii, the increase in fracture toughness is more significant for the more pure alloy. The fracture behavior of investigated alloys with respect to microstructural features and their relation with the fracture micromechanisms were analyzed.
PB  - Elsevier
T2  - Materials and Design
T1  - Influence of notch radius and microstructure on the fracture behavior of Al-Zn-Mg-Cu alloys of different purity
EP  - 1798
IS  - 4
SP  - 1790
VL  - 31
DO  - 10.1016/j.matdes.2009.11.018
ER  - 

@article{
author = "Vratnica, M. and Pluvinage, G. and Jodin, P. and Cvijović, Zorica and Rakin, M. and Burzić, Z.",
year = "2010",
abstract = "The influence of notch radius on the fracture behavior of two high-strength Al-Zn-Mg-Cu alloys with different Fe content in the T73 condition was investigated. The fracture toughness tests were performed on non-fatigue-precracked notched bending specimens with different notch radii ranged from 0.15 mm to 1.0 mm. The obtained data were interpreted using the concept of Notch Fracture Mechanics combined with finite-element method (FEM) calculations. It was found that both alloys are very sensitive to the notch radius. The fracture toughness increases with increasing notch radius. For a given notch radii, the increase in fracture toughness is more significant for the more pure alloy. The fracture behavior of investigated alloys with respect to microstructural features and their relation with the fracture micromechanisms were analyzed.",
publisher = "Elsevier",
journal = "Materials and Design",
title = "Influence of notch radius and microstructure on the fracture behavior of Al-Zn-Mg-Cu alloys of different purity",
pages = "1798-1790",
number = "4",
volume = "31",
doi = "10.1016/j.matdes.2009.11.018"
}

Vratnica, M., Pluvinage, G., Jodin, P., Cvijović, Z., Rakin, M.,& Burzić, Z.. (2010). Influence of notch radius and microstructure on the fracture behavior of Al-Zn-Mg-Cu alloys of different purity. in Materials and Design
Elsevier., 31(4), 1790-1798.
https://doi.org/10.1016/j.matdes.2009.11.018

Vratnica M, Pluvinage G, Jodin P, Cvijović Z, Rakin M, Burzić Z. Influence of notch radius and microstructure on the fracture behavior of Al-Zn-Mg-Cu alloys of different purity. in Materials and Design. 2010;31(4):1790-1798.
doi:10.1016/j.matdes.2009.11.018 .

Vratnica, M., Pluvinage, G., Jodin, P., Cvijović, Zorica, Rakin, M., Burzić, Z., "Influence of notch radius and microstructure on the fracture behavior of Al-Zn-Mg-Cu alloys of different purity" in Materials and Design, 31, no. 4 (2010):1790-1798,
https://doi.org/10.1016/j.matdes.2009.11.018 . .

TY  - CONF
AU  - Cvijović, Zorica M.
AU  - Vratnica, M.
AU  - Cvijović-Alagić, Ivana
PY  - 2009
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5543
AB  - To identify the most important parameters of multiscale microstructural features influencing the fracture modes and resistance to damage, detailed microstructural and fractographic analysis of overaged 7000 alloy plates are performed using the broken plane-strain fracture toughness, K-Ic, test specimens. The geometric characteristics of differently sized second-phase particles are changed by the compositional variations. It was found that the fracture process involves three main micromechanisms. The dominant fracture mode changes with alloy purity, leading to fracture toughness degradation. Quantitative description of fractures by profilometry confirmed that crack initiation and propagation is fostered by the coarse Fe- and Si-rich particles. (C) 2009 Elsevier B. V. All rights reserved
C3  - Procedia Engineering
T1  - The influences of multiscale-sized second-phase particles on fracture behaviour of overaged 7000 alloys
EP  - 38
IS  - 1
SP  - 35
VL  - 1
DO  - 10.1016/j.proeng.2009.06.010
ER  - 

@conference{
author = "Cvijović, Zorica M. and Vratnica, M. and Cvijović-Alagić, Ivana",
year = "2009",
abstract = "To identify the most important parameters of multiscale microstructural features influencing the fracture modes and resistance to damage, detailed microstructural and fractographic analysis of overaged 7000 alloy plates are performed using the broken plane-strain fracture toughness, K-Ic, test specimens. The geometric characteristics of differently sized second-phase particles are changed by the compositional variations. It was found that the fracture process involves three main micromechanisms. The dominant fracture mode changes with alloy purity, leading to fracture toughness degradation. Quantitative description of fractures by profilometry confirmed that crack initiation and propagation is fostered by the coarse Fe- and Si-rich particles. (C) 2009 Elsevier B. V. All rights reserved",
journal = "Procedia Engineering",
title = "The influences of multiscale-sized second-phase particles on fracture behaviour of overaged 7000 alloys",
pages = "38-35",
number = "1",
volume = "1",
doi = "10.1016/j.proeng.2009.06.010"
}

Cvijović, Z. M., Vratnica, M.,& Cvijović-Alagić, I.. (2009). The influences of multiscale-sized second-phase particles on fracture behaviour of overaged 7000 alloys. in Procedia Engineering, 1(1), 35-38.
https://doi.org/10.1016/j.proeng.2009.06.010

Cvijović ZM, Vratnica M, Cvijović-Alagić I. The influences of multiscale-sized second-phase particles on fracture behaviour of overaged 7000 alloys. in Procedia Engineering. 2009;1(1):35-38.
doi:10.1016/j.proeng.2009.06.010 .

Cvijović, Zorica M., Vratnica, M., Cvijović-Alagić, Ivana, "The influences of multiscale-sized second-phase particles on fracture behaviour of overaged 7000 alloys" in Procedia Engineering, 1, no. 1 (2009):35-38,
https://doi.org/10.1016/j.proeng.2009.06.010 . .