脉冲电流对0.27%置氢Ti-6Al-4V合金变形行为的影响

Effect of Applied Pulse Current on Deformation Behavior of Ti-6Al-4V Alloy Charged with 0.27% H

对0.27%(质量分数)置氢Ti-6Al-4V合金进行压缩试验,对断口进行观察与分析,研究了脉冲电流对其变形行为的影响。结果表明,脉冲电流使0.27%置氢和未置氢Ti-6Al-4V合金的变形抗力降低和压缩延伸率提高。脉冲电流产生的焦耳热效应,是影响0.27%置氢Ti-6Al-4V合金力学性能变化的主要原因。由于电致塑性效应的影响,Ti-6Al-4V合金的断裂形式由延性脆性沿晶断裂向准解理穿晶断裂转变,但是对于0.27%置氢Ti-6Al-4V合金,由于在低温条件下氢脆的影响其准解理断裂特征不如未置氢Ti-6Al-4V合金的明显。

The effect of applied pulse current on the deformation behavior of Ti-6 Al-4 V alloy charged with 0.27% H（mass fraction） was investigated by compression test, while the fractured surface was characterized by SEM. Results show that the mechanical property of Ti-6 Al-4 V alloy with and without charge of 0.27% H are both improved by the applied pulse current, i.e. the decrease of deformation resistance and increase of compression elongation. Joule heating effect of the pulse current is the main reason for the mechanical property change of Ti-6 Al-4 V alloy with charge of 0.27% H. The fracture mode of Ti-6 Al-4 V alloy changed from brittle intergranular fracture to quasi cleavage transgranular fracture due to the action of electro-plastic effect. But the quasi cleavage fracture characteristics of the Ti-6 Al-4 V alloy with charge of 0.27% H is not so obvious as that of the as-received alloy due to the apparent hydrogen embrittlement at low temperature.