双相组织TiAl合金在共析温度以下的超塑性  

Superplasticity of Duplex TiAl Based Alloys at Temperatures between 950～1075℃

作　　者：孙坚[1] 傅拥峰[1] 吴建生[1] 贺跃辉[2] 

机构地区：[1]上海交通大学,上海200030 [2]中南工业大学粉末冶金国家重点实验室,长沙410082

出　　处：《材料工程》1999年第9期13-15,23,共4页Journal of Materials Engineering

基　　金：国家自然科学基金

摘　　要：研究了双相组织ＴｉＡｌ合金在温度为９５０～１０７５℃， 应变速率为２×１０－ ４ ～８×１０－ ５ １／ｓ的超塑性行为。结果表明，该合金在上述条件下表现出良好的超塑性，拉伸延伸率最高达到４６７％ 。在温度高于１０２５℃及应变速率不大于７×１０－ ５ １／ｓ 时，应变速率敏感指数均高于０５，最大值为０８以上。该合金超塑性变形的表观激活能为３４５ ｋＪ／ｍ ｏｌ， 在９５０℃双相ＴｉＡｌ合金的超塑性与动态再结晶有关； 而在１０００℃以上ＴｉＡｌ合金在超塑性变形过程中组织稳定， 其超塑性来源于晶界的滑动。Superplatsic deformation behaviours of duplex TiAl based alloys were investigated at temperatures ranging from 950～1075℃, and at strain rate ranging from 2×10 -4 ～8×10 -5 1/s The results show that the alloy exhibits an excellent superplasticity, and a maximum elongation of 467% The strain rate sensitivity reaches at 0 5 and above at a temperature higher than 1025℃ and a strain rate lower than 7×10 -5 1/s The apparent activation energy of the alloy was calculated to be 345 kJ/mol The superplasticity of the alloy is related to dynamic recrystallization during deformation at 950℃ However, at 1000℃ and above the grain size of the alloy keep stable during deformation and the superplasticity is assumed to arise from the grain boundary sliding

关 键 词：超塑性变形 微观组织 钛铝合金 实验 

分 类 号：TG146.23[一般工业技术—材料科学与工程] TG113.25[金属学及工艺—金属材料]