不同结构材料高速应变绝热剪切带分析

Analysis of adiabatic shear bands at high strain rates in three materials with different crystal structures

利用Hopkinson杆,以装甲钢、纯铜及IF钢为材料,采用设计的帽型样尺寸,在不同压力下进行高速冲击,利用EBSD分析其在高应变率变形下的剪切带的特征。结果表明,应变率为104s-1,装甲钢绝热剪切带呈现白亮带状,纯铜及IF钢剪切带宽度较宽且不耐浸蚀。3种材料剪切带内均存在细小等轴晶,装甲钢形成的剪切带取向较分散,但存在稍强的剪切坐标系下的{110}<111>织构,纯铜存在{111}<110>织构,IF钢形成{110}<111>织构。装甲钢抗绝热剪切的性能优于纯铜及IF钢。

Hat-shaped specimens were prepared as designed scale. Adiabatic shear bands （ASBs） pro- duced by using Hopkinson bar in three different materials （including armor steel, pure copper and IF steel） under high velocity impact with different pressures had been investigated by electron backscatter dif- fraction. The results showed that at the strain rates of about 104s-1, the ASBs of armor steel showed white bands while the ASBs of copper and IF steel appeared to be more wider and easier to be eroded. All of them had a common feature that there were equiaxed grains existing inside the ASB. Although the ASBs of armor steel had variable orientations, they had a weak shear texture of {110} 〈 111 〉 in the shear band coordinate system. Similarly, the ASBs of fine copper illustrated a strong { 111 } 〈 110 〉 texture and those of IF steel had a weak { 110 } 〈 111 〉 texture. The property of adiabatic shearing resistance of armor steel is better than that of the pure copper and the IF steel.