TiAl合金细小全层片组织形成机理

TRANSFORMATION MECHANISM OF FINE FULLY LAMELLAR MICROSTRUCTURE IN TiAl ALLOYS

根据对细小全层片组织及其高温转变中间组织的金相和电镜观察分析结果，提出了一种新的双相钛铝合金全层片组织形成机理，即γ／α层片结构在α单相区温度下沿γ相基体中不同取向｛111｝γ惯习面成束形成，而后在冷却过程中转变为层片团细小的γ／α2全层片组织.

The fine fully lamellar (FFL) microstructure and intermedium microstructures in the process of forming FFL microstructure were examined under optical and transmission electronic microscopes. Based on the observation results, the transformation mechanism of FFL microstructure was analyzed and proposed as that the fine γ/α lamellar colonies form at the high temperature in the α single phase region through the precipitating of the α plates on the four equivalent habit planes {111}γ, in each γ matrix grain and then evolve to the γ/α2 lamellar colonies of the FFL microstructure.