用分离式霍普金森压杆对TA2工业纯钛进行了动态压缩及绝热剪切破坏实验研究,得到了不同应变率和不同温度下的宏观应力-应变曲线。通过对压缩本构特性及微观金相破坏的比较分析,讨论了应变率、表观压缩本构特性对绝热剪切形成的影响。结果显示:TA2试样动态压缩呈现绝热剪切破坏特征,绝热剪切带在空间呈对称的双锥形状;应变率越高,形成绝热剪切带的临界应变越小;分析表明,动态压缩实验无法得到关于绝热剪切起始、发展过程的本构软化信息。
Dynamic compression and adiabatic shear failure experiments were carried out for commercially pure titanium TA2 by split Hopkinson pressure bar(SHPB). Macro stress-strain curves were obtained at different strain rates and temperatures. The compressive constitutive characteristics and micro failure were comparatively analyzed and the effects of strain rate and apparent compressive constitutive characteristics on adiabatic shear band(ASB) formation were discussed. Results show that the dynamic compression of TA2 exhibits an adiabatic shear failure characteristic, and the ASBs are of symmetrical bipyramid shape. With the strain rate increasing, the critical strain of ASB formation becomes lower. It is found that the constitutive softening information of the origination and development of ASBs cannot be acquired by dynamic compression tests.