Guan Xinran, Liu Dongrong, Qu Shoujiang, Cao Guojian, Wang Hao, Feng Aihan, Chen Daolun
School of Materials Science and Chemical Engineering, Harbin University of Science and Technology, Harbin 150040, China.
School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.
Materials (Basel). 2024 Jul 24;17(15):3645. doi: 10.3390/ma17153645.
The occurrence of adiabatic shear bands, as an instability phenomenon, is viewed as a precursor to failure caused by instability at high strain rates. Metastable β titanium alloys are extensively utilized due to their excellent mechanical properties, which are often subjected to high strain rate loads in service conditions. Understanding and studying their adiabatic shear instability behavior is thus crucial for preventing catastrophic failure and enhancing material performance. In this study via detailed microstructural analyses in the adiabatic shear region of a Ti-10V-2Fe-3Al alloy subjected to high strain rates, it was observed that α″ martensitic transformation and nano-twinning plus β-to-α phase transformation with α″ martensite as an intermediate phase occurred, in addition to substantial fine grains. The grain refinement mechanisms were mainly related to dynamic recovery dominated by dislocation migration alongside severe plastic deformation.
绝热剪切带的出现作为一种失稳现象，被视为高应变速率下失稳导致失效的先兆。亚稳β钛合金因其优异的力学性能而被广泛应用，在服役条件下它们经常承受高应变速率载荷。因此，了解和研究其绝热剪切失稳行为对于防止灾难性失效和提高材料性能至关重要。在本研究中，通过对经受高应变速率的Ti-10V-2Fe-3Al合金绝热剪切区域进行详细的微观结构分析，观察到除了大量细晶外，还发生了α″马氏体相变以及以α″马氏体为中间相的纳米孪晶加β向α相变。晶粒细化机制主要与由位错迁移主导的动态回复以及严重塑性变形有关。
