置氢Ti-6Al-4V钛合金的热压缩变形行为研究

通过热模拟压缩实验,研究了氢对Ti-6Al-4V钛合金热变形行为的影响。结果表明,置氢可以显著降低Ti-6Al-4V钛合金高温压缩时的流动应力,提高Ti-6Al-4V钛合金的热加工变形速率一个数量级以上,并且明显降低了Ti-6Al-4V钛合金的变形温度。在变形温度760℃~800℃范围内,置氢量为0.4wt%的Ti-6Al-4V钛合金的流动应力最小;在变形温度840℃~920℃范围内,置氢量0.2wt%的Ti-6Al-4V钛合金的流动应力最小。同时,置氢前后Ti-6Al-4V钛合金的变形激活能计算结果表明,置氢量为0.4wt%的Ti-6Al-4V钛合金在α+β两相区的变形激活能为208.3kJ/mol,与未置氢Ti-6Al-4V钛合金相比降低了316kJ/mol。

Deformation behavior in the isothermal compression of hydrogenated Ti-6Al-4V alloy

Effect of hydrogen on deformation behavior of the Ti-6Al-4V alloy was investigated through isothermal compression.Addition of hydrogen decreases significantly flow stress,improves strain rate of more than one order of magnitude and decreases significantly deformation temperature of the Ti-6Al-4V alloy.The minimum flow stress of Ti-6Al-4V alloy is at a hydrogen content of 0.4wt% in the deformation temperature range from 760℃ to 800℃,but the minimum flow stress is at a hydrogen content of 0.2wt% in the deformation temperature range from 840℃ to 920℃.Meanwhile,apparent activation energy for deformation of the Ti-6Al-4V alloy is 208.3kJ/mol at a hydrogen content of 0.4wt% in α+β two-phase field,decreasing 316kJ/mol in comparison with that of the Ti-6Al-4V alloy with natural hydrogen.