工业纯钛动态压缩特性及破坏的实验研究

Experimental Study on Mechanical Properties and Failure characteristic of a Commercially Pure Titanium under Dynamic Compression

摘要:

本文利用分离式霍普金森压杆对工业纯TA2进行了动态压缩及绝热剪切破坏进行了实验研究，得到不同应变率和温度下的宏观应力-应变关系曲线。通过对压缩本构特性及微观金相破坏的比较分析，讨论了加载率、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；随加载率提高，绝热剪切带形成的临界应变越小；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。

Abstract:

Pure titanium TA2 alloy was tested by Split Hopkinson Pressure Bar (SHPB) under uniaxial dynamic compression conditions with different strain rates and room temperatures. Adiabatic shear bands were found in the specimens by metallographic after compression tests. As a result, we found strain and strain rate were so important for the initiation of shear bands. A critical strain must be arrived when the shear bands occur, and the larger strain rate, the smaller critical strain.