Microstructural evolution of a forged TiAl based alloy during heat treatment at subtransus temperature

来源期刊：中国有色金属学报(英文版)2000年第2期

论文作者：唐建成 黄伯云 刘文胜 贺跃辉

文章页码：183 - 186

Key words：TiAl base alloy; heat treatment; microstructure

Abstract: Microstructural evolution of a forged TiAl based alloy during heat treatment from 1180℃ to 1300℃ was investigated. The grain sizes of the alpha phases as well as the sizes and the volume fractions of the gamma phases were evaluated as a function of heat treatment temperature and time. When the alloys are isothermally heat treated at subtransus temperatures, the sizes of gamma phases(D_γ) increase slightly with heat treatment temperature and time and those of alpha phases(D_α) and the volume fractions of gamma phases(φ_γ) vary significantly with holding time in the early stages of heat treatments, but after heat treatments for 2 h,φ_γ reveal little variations with holding times and D_α approach limits, which can be described by D_α 0=0.65 D_γ/φ_γ. Besides, it has been found that the alpha phases in the specimens heat treated at 1 260℃ and 1 300℃ contain lamellar structures, at low temperatures, however, appear featureless.