Effect of Heat Treatment on the Microstructure of Two-step Forging for High Nb Containing TiAl Alloy

Effect of heat treatment processings on the microstructure of two-step forging for high Nb containing TiAl alloy was investigated. Different heat treatment processes were employed to obtain different microstructures of Ti-45Al-9(Nb,W,B,Y) alloy. The results show that, after the heat treatment of 1310/20min+1250/2h/AC, the β phase can be efficiently eliminated and the uniform fine duplex microstructures can be gained. Followed by the heat treatment at α single phase region directly, striped FL microstructure of coarse colony and fine colony is obtained. The holding at (α+γ) phase region can result in the homogenous fine FL microstructure relatively. The FL microstructure produced by the heat treatment of HT6 is the most homogenous and finest.