不同应力状态下TC6钛合金不同组织绝热剪切敏感性研究

Study on Adiabatic Shearing Sensitivity of Different Microstructures of TC6 Titanium Alloy at Different Stress States

采用分离式霍普金森压杆装置,对TC6钛合金不同组织的圆柱试样和帽形试样分别进行应变率为103s-1量级的动态压缩及动态剪切试验,结合力学响应及微观分析研究不同应力状态下TC6钛合金3种典型组织的绝热剪切敏感性。结果表明:在单轴压缩应力状态下,TC6钛合金3种典型组织绝热剪切敏感性从高到低依次为网篮组织、等轴组织、双态组织;在压剪复合应力状态下,3种典型组织在动态剪切时的绝热剪切敏感性从大到小依次为等轴组织、双态组织、网篮组织;应力状态不同,组织绝热剪切敏感性的差异实质上体现了组织在不同应力状态下的塑性变形能力及绝热剪切带在不同组织中扩展的难易程度。

By means of split Hopkinson bar,the dynamic compression and dynamic shear tests on TC6 titanium alloy with different microstructures were carried out under the condition of high strain-rate loading;the specimens are cylindrical and hat-shaped,respectively.The adiabatic shearing sensitivities of the three kinds of typical microstructures of TC6 titanium alloy at different stress states were studied by mechanical response and micro-analysis.Results show that at the stress state of uniaxial compression,the descending order for the adiabatic shearing sensitivities of these typical microstructures are basketwave,equiaxed and duplex.And at the stress state of compression-shearing combination,their descending order is equiaxed,duplex and basketwave.The difference in the adiabatic shearing sensitivity is substantively the embodiment of plastic deforming ability of different microstructures at different stress states and spreading ability of adiabatic shear band in different microstructures.