Microstructural evolution of TiAl base alloy during three-stepped thermo-mechanical treatment

来源期刊：中南大学学报(英文版)2001年第1期

论文作者：LIU Yong LIU Feng-xiao HUANG Bai-yun ZHOU Ke-chao ZHANG Chuan-fu

文章页码：9 - 12

Key words：TiAl base alloy; hot forging; microstructure

Abstract: ATiAl base alloy ingotwith a height-to-diameter ratio of 2.2 was broken down by multiple step canned forging. The microstructures after every deformation and subsequent recrystallization were observed by optical microscopy. Results showthat at the first step the reduction should be carefully controlled in case of double-bulge and crack of the ingot. After the first annealing, recrystallization occurred at the deformed grain boundaries and inside the grain. The recrystallizedmicrostructure is favorable forfurther deformation. After the second deformation and annealing, coarsening of the lamellae occurred and the microstructure became equiaxed. Bythe final deformation and subsequent recrystallization, the coarse lamellar colony can be refined to about 20μm, and homogeneousmicrostructurewas obtained fromthe ingotwith a large initial height-to-diame-ter ratio.