TY - JOUR
T1 - Nonequilibrium thermodynamics perspective for shear localization in additive manufacturing
AU - Rao, Wei
AU - Kang, Guozheng
AU - Zhang, Xu
AU - Shen, Qianye
AU - Tao, Ran
AU - Yang, Qingsheng
AU - Fang, Daining
N1 - Publisher Copyright:
© 2026 Elsevier Ltd
PY - 2026/4/15
Y1 - 2026/4/15
N2 - Shear localization during deformation of additively manufactured Ti-6Al-4V alloy leads to macroscopic strain softening and premature failure, severely limiting component performance in aerospace applications, yet its underlying physical mechanisms remain unclear. This study systematically investigates the formation mechanism of shear localization through experiments and constitutive modeling. Monotonic tensile tests and microscopic characterization results reveal a strong correlation between shear localization and intrinsic microstructural heterogeneity. To elucidate the mechanism, a constitutive model is developed within an irreversible thermodynamic framework, incorporating local non-equilibrium configuration characteristics, dislocation evolution, and cumulative plastic damage. The comparison of the predicted results with the experiments demonstrated the effectiveness of the new constitutive model. Analysis of modeling results revealed that interactions between pore defects and heterogeneous microstructures induce local damage, which ultimately contributes to pronounced shear localization. Furthermore, more significant structural heterogeneity caused by severe local shear promotes dislocation accumulation, which subsequently facilitates the propagation and diffusion of shear bands. This work clarifies the physical origin of shear localization in additively manufactured titanium alloys, providing a new theoretical perspective for understanding their deformation and failure mechanisms.
AB - Shear localization during deformation of additively manufactured Ti-6Al-4V alloy leads to macroscopic strain softening and premature failure, severely limiting component performance in aerospace applications, yet its underlying physical mechanisms remain unclear. This study systematically investigates the formation mechanism of shear localization through experiments and constitutive modeling. Monotonic tensile tests and microscopic characterization results reveal a strong correlation between shear localization and intrinsic microstructural heterogeneity. To elucidate the mechanism, a constitutive model is developed within an irreversible thermodynamic framework, incorporating local non-equilibrium configuration characteristics, dislocation evolution, and cumulative plastic damage. The comparison of the predicted results with the experiments demonstrated the effectiveness of the new constitutive model. Analysis of modeling results revealed that interactions between pore defects and heterogeneous microstructures induce local damage, which ultimately contributes to pronounced shear localization. Furthermore, more significant structural heterogeneity caused by severe local shear promotes dislocation accumulation, which subsequently facilitates the propagation and diffusion of shear bands. This work clarifies the physical origin of shear localization in additively manufactured titanium alloys, providing a new theoretical perspective for understanding their deformation and failure mechanisms.
KW - Additively manufactured
KW - Constitutive model
KW - Nonequilibrium microstructure
KW - Shear localization
KW - Ti-6Al-4V alloy
KW - Void defects
UR - https://www.scopus.com/pages/publications/105032528695
U2 - 10.1016/j.ijmecsci.2026.111459
DO - 10.1016/j.ijmecsci.2026.111459
M3 - Article
AN - SCOPUS:105032528695
SN - 0020-7403
VL - 316
JO - International Journal of Mechanical Sciences
JF - International Journal of Mechanical Sciences
M1 - 111459
ER -