【摘要】 研究了锻造 Ti- 48Al- 2 Cr(at% )在 1180℃到 132 0℃热处理时的组织演变 ,分析了在不同温度等温热处理时晶粒长大的动力学。在 Ta以上等温热处理时 ,晶粒长大迅速 ,其晶粒长大因子为 2 .4。在 Ta以下等温热处理时 ,当热处理时间由 10 min不断延长到 4h时 ,γ晶粒尺寸变化较小 ,α晶粒不断长大。热处理温度越高 ,α晶粒长大越快 ,在 1180℃ ,12 2 0℃ ,12 6 0℃和 130 0℃热处理时 ,α晶粒长大因子分别为 2 .9,2 .8,2 .6 5和 2 .5更多还原

【Abstract】 Microstructural variation during the heat treatment of forged Ti 48Al 2Cr(at. %) in the temperature range of 1180℃ to 1320℃ has been investigated. The kinetics of grain growth were analyzed. Isothermal heat treatment at temperatures above the α transus leads to rapid grain growth, and the grain growth exponent being 2 4. Isothermal heat treatment at subtransus temperatures leads to little variation of γ particle size and a progressive increase of α grain with increasing heat treatment time from 10 min to 4 h. And the growth rate of alpha grains decreases with decreasing heat treating temperature. When forged TiAl based alloys are heat treated at 1180℃, 1220℃,1260℃ and 1300℃, the grain growth exponents of α grains are 2.9, 2.8, 2.65 and 2.5 respectively.更多还原