摘要
研究了Ti-44Al-8Nb合金高温固态置氢过程中微观组织演化规律,并考察了氢对Ti Al合金高温变形行为的影响。结果表明,Ti-44Al-8Nb合金吸氢过程是一个吸热过程,合金的吸氢量随着置氢温度、置氢时间、氢流量的提高而逐渐提高;置氢合金中的残余B2相含量较高,这归因于氢为beta稳定元素,在高温固态置氢过程中稳定B2相;在T_α温度以上进行固态置氢和等温热处理后,合金微观组织由枝晶向等轴晶转变,且置氢后合金的晶界光滑平直,主要是由氢降低界面能引起的;氢能够大幅降低高Nb-Ti Al合金的高温变形抗力,在变形温度为1200℃和应变速率为0.01 s^(-1)条件下,添加0.043%H(质量分数,下同)后,合金峰值应力降低40%。
This study focused on the hydrogen absorption behavior of Ti-44Al-8Nb alloy at high temperature.The effect of hydrogen on its microstructural evolution and hot deformation behavior were studied.The results show that hydrogen absorption in Ti Al alloy is an endothermic reaction;hydrogen content increases with the increasing of hydrogenation temperature,hydrogenation time and hydrogen flow rate,which is sensitive to hydrogenation temperature.The residual B2 phase in the hydrogenated alloy is more than that in unhydrogenated alloy because hydrogen is beta stabilizing element.The grain boundary is smooth when hydrogenated above 1280oC due to the hydrogen-reduced interface energy.Hydrogen can decrease the flow stress of Ti Al alloys significantly,which is decreased by 40% after hydrogenated with 0.043wt% H under strain rate of 0.01 s^(-1 )at 1200oC.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2017年第S1期20-24,共5页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51274076)
关键词
TIAL合金
固态置氢
组织演化
高温变形
TiAl alloys
thermohydrogen processing
microstructure evolution
hot deformation
