加热速度对TiAl基合金显微组织的影响

来源期刊：中南大学学报(自然科学版)2002年第1期

论文作者：彭超群 黄伯云 贺跃辉

文章页码：45 - 48

关键词：TiAl基合金;快速加热;循环热处理;组织细化;形核

Key words：TiAl-based alloy; rapid heating; cyclic heat treatment; microstructural refinement; nucleation

摘    要：利用Gleeble-1500热模拟机研究了加热速度对铸态TiAl基合金显微组织的影响,提出了在相界处形成层片组织的物理模型.结果表明,5次快速加热循环热处理可将TiAl基合金晶粒细化至50μm以下;单次快速加热可破坏TiAl基合金层片组织的稳定性,使层片组织破碎.快速加热条件下的重结晶形核以晶界形核为主,并可在相界发生.

Abstract: The effects of heating rate on microstructure of a TiAl-based alloy was studied by using the Gleeble-1500 thermal simulator; a physical model is proposed for explaining the formation of fine lamellae at the phase interfaces. The results show that 5 times rapid heating cyclic heat treatment can refine the grain size to less than 50μm; single rapid heating treatment can significantly damage the structural stability of the lamallae. The optical microstructure observations show that during rapid heating, the neocrystallization nucleationm ainlyoccurs atthe grain boundaries and also at the phase interfaces.