TY  - JOUR
AU  - Cvijović, Zorica M.
AU  - Vratnica, M.
AU  - Cvijović-Alagić, Ivana
PY  - 2011
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4247
AB  - The article deals with the relations between microstructural parameters, microscopic fracture mechanisms, and resultant plane-strain fracture toughness, K(IC), of hot-forged 7000 alloy plates in overaged condition. Three industrially produced alloys with the (Zn + Mg + Cu) content of similar to 11.5 mass% and different contents of (Fe + Si) impurities (from 0.23 to 0.37 mass%) were used. The variation in alloy purity generated differences in the geometric characteristics of coarse intermetallic phase particles, exerting significant effect on fracture behavior of these alloys. To evaluate the fracture mechanism, characterization of the broken K(IC) test specimen surfaces was performed using scanning electron microscopy. Three micromechanisms governing fracture process were identified. The extent of primary voiding at coarse intermetallic phase particles increases systematically with the increase of (Fe + Si) level, whereas the extent of intergranular/transgranular fracture decreases. This observation was confirmed by a quantitative description of fractures by means of a profilometric method. It was found that morphological parameters of the fracture profiles clearly differentiate between different fracture modes and offer conclusive proof that coarse voiding at fractured intermetallic phase particles dominates fracture at low alloy purity. A higher fraction of coarse voiding is shown to result in an overall reduction of fracture toughness.
T2  - International Journal of Damage Mechanics
T1  - Effect of Alloy Purity on Fracture Behavior of Overaged 7000 Alloy Plates
VL  - 20
IS  - 2
SP  - 179
EP  - 193
DO  - 10.1177/1056789509346684
ER  - 

@article{
author = "Cvijović, Zorica M. and Vratnica, M. and Cvijović-Alagić, Ivana",
year = "2011",
abstract = "The article deals with the relations between microstructural parameters, microscopic fracture mechanisms, and resultant plane-strain fracture toughness, K(IC), of hot-forged 7000 alloy plates in overaged condition. Three industrially produced alloys with the (Zn + Mg + Cu) content of similar to 11.5 mass% and different contents of (Fe + Si) impurities (from 0.23 to 0.37 mass%) were used. The variation in alloy purity generated differences in the geometric characteristics of coarse intermetallic phase particles, exerting significant effect on fracture behavior of these alloys. To evaluate the fracture mechanism, characterization of the broken K(IC) test specimen surfaces was performed using scanning electron microscopy. Three micromechanisms governing fracture process were identified. The extent of primary voiding at coarse intermetallic phase particles increases systematically with the increase of (Fe + Si) level, whereas the extent of intergranular/transgranular fracture decreases. This observation was confirmed by a quantitative description of fractures by means of a profilometric method. It was found that morphological parameters of the fracture profiles clearly differentiate between different fracture modes and offer conclusive proof that coarse voiding at fractured intermetallic phase particles dominates fracture at low alloy purity. A higher fraction of coarse voiding is shown to result in an overall reduction of fracture toughness.",
journal = "International Journal of Damage Mechanics",
title = "Effect of Alloy Purity on Fracture Behavior of Overaged 7000 Alloy Plates",
volume = "20",
number = "2",
pages = "179-193",
doi = "10.1177/1056789509346684"
}

Cvijović, Z. M., Vratnica, M.,& Cvijović-Alagić, I.. (2011). Effect of Alloy Purity on Fracture Behavior of Overaged 7000 Alloy Plates. in International Journal of Damage Mechanics, 20(2), 179-193.
https://doi.org/10.1177/1056789509346684

Cvijović ZM, Vratnica M, Cvijović-Alagić I. Effect of Alloy Purity on Fracture Behavior of Overaged 7000 Alloy Plates. in International Journal of Damage Mechanics. 2011;20(2):179-193.
doi:10.1177/1056789509346684 .

Cvijović, Zorica M., Vratnica, M., Cvijović-Alagić, Ivana, "Effect of Alloy Purity on Fracture Behavior of Overaged 7000 Alloy Plates" in International Journal of Damage Mechanics, 20, no. 2 (2011):179-193,
https://doi.org/10.1177/1056789509346684 . .

TY  - CONF
AU  - Cvijović, Zorica M.
AU  - Vratnica, M.
AU  - Cvijović-Alagić, Ivana
PY  - 2009
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6865
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
VL  - 1
IS  - 1
SP  - 35
EP  - 38
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",
volume = "1",
number = "1",
pages = "35-38",
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 . .

TY  - JOUR
AU  - Cvijović, Zorica M.
AU  - Vratnica, M.
AU  - Rakin, Marko P.
AU  - Cvijović-Alagić, Ivana
PY  - 2008
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3590
AB  - An attempt has been made to model the plane-strain fracture toughness, KIc, in Al-Zn-Mg-Cu alloy forgings subjected to overageing. The proposed model, based on the multiple micromechanisms, reveals the quantitative relations between fracture toughness, fraction of all fracture modes and microstructural parameters associated with multiscale-sized second-phase particles and precipitate-free zones. The new model is validated by the present quantitative data of microstructural and fractographic analysis performed along with mechanical tests on hot-forged plates in T73 condition. The relevant parameters changed by the compositional variations were determined in two orientations. It was found that the predicted KIc values represent the tendency of fracture toughness change well. The new model provides better agreement for the case of dominant transgranular fracture mode.
T2  - Philosophical Magazine
T1  - Micromechanical model for fracture toughness prediction in Al-Zn-Mg-Cu alloy forgings
VL  - 88
IS  - 27
SP  - 3153
EP  - 3179
DO  - 10.1080/14786430802502559
ER  - 

@article{
author = "Cvijović, Zorica M. and Vratnica, M. and Rakin, Marko P. and Cvijović-Alagić, Ivana",
year = "2008",
abstract = "An attempt has been made to model the plane-strain fracture toughness, KIc, in Al-Zn-Mg-Cu alloy forgings subjected to overageing. The proposed model, based on the multiple micromechanisms, reveals the quantitative relations between fracture toughness, fraction of all fracture modes and microstructural parameters associated with multiscale-sized second-phase particles and precipitate-free zones. The new model is validated by the present quantitative data of microstructural and fractographic analysis performed along with mechanical tests on hot-forged plates in T73 condition. The relevant parameters changed by the compositional variations were determined in two orientations. It was found that the predicted KIc values represent the tendency of fracture toughness change well. The new model provides better agreement for the case of dominant transgranular fracture mode.",
journal = "Philosophical Magazine",
title = "Micromechanical model for fracture toughness prediction in Al-Zn-Mg-Cu alloy forgings",
volume = "88",
number = "27",
pages = "3153-3179",
doi = "10.1080/14786430802502559"
}

Cvijović, Z. M., Vratnica, M., Rakin, M. P.,& Cvijović-Alagić, I.. (2008). Micromechanical model for fracture toughness prediction in Al-Zn-Mg-Cu alloy forgings. in Philosophical Magazine, 88(27), 3153-3179.
https://doi.org/10.1080/14786430802502559

Cvijović ZM, Vratnica M, Rakin MP, Cvijović-Alagić I. Micromechanical model for fracture toughness prediction in Al-Zn-Mg-Cu alloy forgings. in Philosophical Magazine. 2008;88(27):3153-3179.
doi:10.1080/14786430802502559 .

Cvijović, Zorica M., Vratnica, M., Rakin, Marko P., Cvijović-Alagić, Ivana, "Micromechanical model for fracture toughness prediction in Al-Zn-Mg-Cu alloy forgings" in Philosophical Magazine, 88, no. 27 (2008):3153-3179,
https://doi.org/10.1080/14786430802502559 . .

TY  - JOUR
AU  - Cvijović, Zorica M.
AU  - Rakin, Marko P.
AU  - Vratnica, M.
AU  - Cvijović, Ivana
PY  - 2008
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3389
AB  - The effects of microstructural parameters associated with the coarse intermetallic phases particles and precipitates on the fracture toughness of the overaged 7000 alloy forgings are investigated. Detailed microstructural and fractographic analysis together with fracture toughness tests are carried out using three alloys with different (Fe + Si) contents. The fracture mechanisms are identified and area fractions of different fracture modes are assessed. The data are then quantitatively correlated to plane-strain fracture toughness, K-Ic, and the bulk microstructural attributes estimated via image analysis. A multiple micromechanism-based model is developed, which accurately describes the dependence of K-Ic on individual microstructural parameters. (C) 2007 Published by Elsevier Ltd.
T2  - Engineering Fracture Mechanics
T1  - Microstructural dependence of fracture toughness in high-strength 7000 forging alloys
VL  - 75
IS  - 8
SP  - 2115
EP  - 2129
DO  - 10.1016/j.engfracmech.2007.10.010
ER  - 

@article{
author = "Cvijović, Zorica M. and Rakin, Marko P. and Vratnica, M. and Cvijović, Ivana",
year = "2008",
abstract = "The effects of microstructural parameters associated with the coarse intermetallic phases particles and precipitates on the fracture toughness of the overaged 7000 alloy forgings are investigated. Detailed microstructural and fractographic analysis together with fracture toughness tests are carried out using three alloys with different (Fe + Si) contents. The fracture mechanisms are identified and area fractions of different fracture modes are assessed. The data are then quantitatively correlated to plane-strain fracture toughness, K-Ic, and the bulk microstructural attributes estimated via image analysis. A multiple micromechanism-based model is developed, which accurately describes the dependence of K-Ic on individual microstructural parameters. (C) 2007 Published by Elsevier Ltd.",
journal = "Engineering Fracture Mechanics",
title = "Microstructural dependence of fracture toughness in high-strength 7000 forging alloys",
volume = "75",
number = "8",
pages = "2115-2129",
doi = "10.1016/j.engfracmech.2007.10.010"
}

Cvijović, Z. M., Rakin, M. P., Vratnica, M.,& Cvijović, I.. (2008). Microstructural dependence of fracture toughness in high-strength 7000 forging alloys. in Engineering Fracture Mechanics, 75(8), 2115-2129.
https://doi.org/10.1016/j.engfracmech.2007.10.010

Cvijović ZM, Rakin MP, Vratnica M, Cvijović I. Microstructural dependence of fracture toughness in high-strength 7000 forging alloys. in Engineering Fracture Mechanics. 2008;75(8):2115-2129.
doi:10.1016/j.engfracmech.2007.10.010 .

Cvijović, Zorica M., Rakin, Marko P., Vratnica, M., Cvijović, Ivana, "Microstructural dependence of fracture toughness in high-strength 7000 forging alloys" in Engineering Fracture Mechanics, 75, no. 8 (2008):2115-2129,
https://doi.org/10.1016/j.engfracmech.2007.10.010 . .