Composition Optimization of β‐γ TiAl Alloys Containing High Niobium

Abstract

The as-cast microstructures, hot deformation behaviors and asdeformed microstructures of P-y TiAl alloys containing high niobium and various p stabilizing elements Mn, Cr, Mo and V were investigated. It is found that the increasing addition of Cr and Mo elements contributes to the continuous decrease of flow stress. On the contrary, with increasing the amount of V content, the flow stress enhances. In the Mn content addition range 0.5~2.0at%, the alloy with 1.5%Mn possesses the minimum value of flow stress. The optimum composition for hot working is Ti-44Al-8Nb-1.5Mn-0.2B-0.2Y. The morphology of P phase as well as the amount of P phase plays an important role in controlling the formability of P-y TiAl alloys containing high niobium.