全层片状组织的TiAl基合金高温塑性的研究

Study of Plasticity of TiAl-Based Alloy with Full-Lamellar Microstructure at Elevated Temperature

采用自制悬垂式流变拉伸机研究了ＴｉＡｌ基合金全层片状组织试样的高温塑性变形行为及过程。试验结果表明，在保持较稳定的应变速率工艺下，合金在９００℃的高温变形能力达７５．５％。动态再结晶促使γ相的形成，并在一定条件下导致混晶现象的出现。锯齿状晶界与混晶现象的存在，被认为是试样拉伸断裂的主要原因。

Suspended rheology tensile testing machine (SRTTM) has been used to investigate the elevated temperature plastic deformation of TiAl-based alloy with full-lamellar microstructure. It has been found that the alloy could show 7 5.5% high elogation when the strain rate was kept stability,The dynamic recrystallization has caused the formation of single γ phase grains and resulted in the appearance of mixed sizes of grains under proper conditions.The existence of serrated grain boundaries and mixed sizes of grains were thought as the main causes of the tensile fracture.