置氢Ti-6Al-4V合金组织演变与超塑性能

Microstructure evolution and superplasticity of hydrogenated Ti-6Al-4V titanium alloy

应用高温拉伸实验研究了氢对Ti-6Al-4V合金超塑变形行为的影响,借助于OM、SEM、TEM和XRD等分析手段,分析了氢对钛合金组织演变的影响.结果表明:氢可促进合金中β相数量的增加,氢质量分数达到0.2%时合金出现马氏体组织,并随着氢含量的增加而逐渐粗化;适量的氢可以改善钛合金超塑变形行为,如降低流动应力和超塑变形温度、提高应变速率敏感指数m值;Ti-6Al-4V合金加入质量分数0.1%的氢,其峰值流动应力降低53%,变形温度降低约60℃,且由于氢的加入,使得超塑变形后的位错密度减少,说明氢促进了位错的运动.

High temperature tensile experiments were earned out to investigate the effect of hydrogen on the superplastic deformation behavior of Ti-6Al-4V titanium alloy. The influence of hydrogen on the microstructure evolution of the alloy was analyzed by OM, SEM, TEM, and XRD. The results show that the amount of 13 phase in the hydrogenated alloy increases with increasing hydrogen content, and martensite begins to form while the mass content of hydrogen reaches to 0.2% and becomes coarser with the increase in hydrogen content. A reasonable hydrogen content can improve the superplastic behavior such as increasing the m value and lowering the flow stress and temperature. The addition of 0.1% hydrogen in Ti-6Al-4V alloy ean result in a decrease in peak flow stress of 53 % and a decrease in deformation temperature of 6012 . Due to addition of hydrogen the dislocation density of the hydrogenated alloy after deformation is lower than that of the unhydrogenated alloy.