摘要
研究了大晶粒 Ti- 47% Al- 2 % Mn- 2 % Nb- 1 % B合金的高温变形行为 .该合金具有近等轴γ组织 ,其间均匀分布着少量极细的α2 相 .测试在空气中进行 ,试样用釉涂覆加以保护 ,温度为 1 0 2 5～ 1 1 0 0°C,初始应变速率范围为 (0 .0 4～ 1 .2 8)× 1 0 -3 s-1.该合金表现出和常规细晶超塑性材料相同的变形特征 ,而无需满足细晶和晶界滑移的先决条件 .在所研究的大多数情况下 ,均可获得2 0 0 %以上的延伸率 .1 1 0 0°C,4× 1 0 -5s-1均匀变形条件下可获得 2 87.5%的最大延伸率 ,相应的应变速率敏感指数为 0 .39.超塑变形后观察到显著的晶粒细化 .
High temperature deformation behavior was investigated systematically in a large-grained Ti-47%Al-2%Mn-2%Nb-2%B alloy having nearly equiaxed γ phase, in which fine particles of β distribute uniformly. Specimens coated with enamel are tested in air at 1025°C-1100°C and the initial strain rates of 4×10-5-1.28×10-3 s-1. The TiAl alloy exhibits all deformation characteristics of conventionally fine grained superplastic materials without the prerequisites of fine grain size and grain boundary sliding. In most cases, an elongation of more than 200% can be obtained. A maximum elongation of 287.5% with an m value of 0.39 is obtained at 1100°C and initial strain rate of 4×10-5 s-1 under the condition of uniform deformation. Significant refining of the original grain size is observed during and after superplastic deformation.
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
2001年第3期380-384,共5页
Journal of Shanghai Jiaotong University
基金
国家自然科学基金!资助项目 (5 9895 15 0 )
