电脉冲热处理对网篮组织热轧TC4力学性能和绝热剪切特性的影响

Effects of electric pulse heat treatment on mechanical properties and adiabatic shear banding of hot-rolled lamellar TC4 alloy

摘要:

利用SPS设备对网篮组织热轧TC4进行电脉冲热处理，研究了电脉冲热处理对TC4力学性能和绝热剪切特性的影响。结果表明，电脉冲热处理对TC4的静态压缩强度、塑性和动态压缩屈服强度无明显影响，对TC4的绝热剪切临界破坏应变和绝热剪切破坏前材料的单位体积吸收功有显著影响，经900℃热处理后，TC4的绝热剪切临界破坏应变和单位体积吸收功均达到最大值，与未热处理的热轧TC4相比分别提高了57%和42%，表明TC4的绝热剪切敏感性显著降低。微观分析表明，电脉冲处理可调节TC4的原始β晶粒尺寸、集束尺寸和板条宽度等细节组织特征，经900℃电脉冲热处理后，热轧TC4的原始β晶粒尺寸显著细化，β转变组织集束尺寸增大，α板条宽度保持不变。

Abstract:

The effects of electric pulse heat treatment performed by SPS equipment on mechanical properties and the susceptibility to adiabatic shear bands of hot-rolled TC4 alloy were systematically studied. The results show that electric pulse heat treatment has little effect on the strength and ductility of TC4 at the static compression loading,and it also has little effect on the yielding strength at the dynamic compression loading, but the heat treatment has evidently effects on the susceptibility to adiabatic shear bands of the hot-rolled TC4.After electric pulse heat treatment at 900℃, TC4 alloy exhibits the highest adiabatic shear failure strain under the dynamic compression loading and the highest energy absorption of unit volume before fracture. Compared with the hot-rolled TC4 alloy, the adiabatic shear failure strain of heat -treated TC4 increases by 57% and the energy absorption of unit volume increases by 42%, indicating that the susceptibility to adiabatic shear bands of TC4 is significantly decreased. The microstructure analysis results show that electric pulse heat treatment has obviously influences on the prior β grain size and the detailed microstructure characteristics of TC4. After the heat treatment at 900℃, the oprior β grain size shows decreasing tendency, while the transformed β colony size shows increasing tendency, but the width of α plate shows no change.