研究了热处理对二次锻造高Nb-TiAl基合金组织的影响。通过对Ti-45Al-9(Nb,W,B,Y)金属间化合物进行不同的热处理,得到不同的显微组织。结果表明,经1310℃/20min+1250℃/2h/AC热处理后,β相被有效地消除,得到细小均匀的双态组织。此后直接加热到α单相区,得到条带状的全片层组织。增加在两相区的停留,得到相对比较均匀细小的全片层组织。将锻造组织先转变为近γ组织再进行全片层组织处理,得到最均匀细小的全片层组织。

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.