Abstract The relation between stress collapse and nucleation of adiabatic shear band (ASB) remains incompletely understood. To further understand this topic, the evolution of shear deformation of Ti-6Al-4V alloy under forced shear loading is systematically investigated using digital image correlation (DIC) technique. DIC results indicate that ASB nucleates after the maximum stress and drastic stress drop corresponds to the initiation and propagation of crack, and the forced shear process can be divided into homogeneous, inhomogeneous and highly localized deformation stages. Numerical simulation results suggest that thermal softening might not have had a pronounced effect on the onset of adiabatic shear band and dynamic recrystallization formation. ‘‘Cohesive fracture” can be identified as the dynamic failure mechanism for Ti-6Al-4V alloy on the basis of the crack propagation features, and the microstructure gets increasingly refined due to the occurrence of dislocations, stacking faults and cell structures.

中文翻译：

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Ti-6Al-4V合金扁帽形试样动态强迫剪切特性

摘要 绝热剪切带(ASB) 的应力坍塌与成核之间的关系仍不完全清楚。为了进一步理解这一主题，使用数字图像相关 (DIC) 技术系统地研究了 Ti-6Al-4V 合金在强制剪切载荷下剪切变形的演变。DIC结果表明，ASB在最大应力和急剧应力下降后成核，对应于裂纹的萌生和扩展，强迫剪切过程可分为均质、非均质和高度局部化变形阶段。数值模拟结果表明，热软化可能对绝热剪切带的开始和动态再结晶的形成没有显着影响。