高温处理后T2铜在高应变率下的动态力学性能

Dynamic mechanical properties of T2 copper under high strain rate after high temperature treatment

为分析高温处理后T2铜在高应变率下的动态力学性能,利用分离式霍普金森压杆(SHPB)对高温处理后的T2铜试样进行应变率为(2 000~4 000)s-1的动态压缩试验,得到各处理温度下的应力-应变曲线,分析其温度及应变率敏感性,研究晶粒尺寸对屈服应力及流变应力的影响。结果表明:随着处理温度的升高,T2铜的屈服应力、流变应力降低,表现出明显的高温软化效应;T2铜的峰值应力、应变与应变率间有较强的线性关系,具有一定的应变率敏感性;高温处理后,T2铜晶粒尺寸随处理温度的升高而增大,晶界数随晶粒的增大不断减少,导致屈服应力和流变应力降低,说明T2铜动态力学性能具有温度敏感性。

To analyze the dynamic mechanical properties of T2 copper under high strain rate after high temperature treatment,dynamic compression experiments were carried out by using the split hopkinson pressure bar(SHPB)test system for T2 copper after high temperature treatment with the strain rate in the range of(2 000-4 000)s-1. The stress-strain curve of each processing temperature was obtained. The temperature sensitivity and strain rate sensitivity of T2 copper were analyzed. And the different temperature treatment after grain size effect on the yield stress and flow stress were studied. The results show that with the increase of treatment temperature,the yield stress and flow stress of T2 copper decrease,showing obvious high temperature softening effect;The peak stress,peak strain and strain rate of T2 copper have a strong linear relationship and have certain strain rate sensitivity;After high temperature treatment,the grain size of T2 copper increases with the increase of treatment temperature,and the number of grain boundaries decreases with the increase of grain size,which leads to the decrease of yield stress and flow stress,indicating that the dynamic mechanical properties of T2 copper are temperature sensitive.