Effect of texture on mechanical anisotropy of Ti–47Al–2Cr-0.2Mo intermetallics

Abstract

The anisotropy of mechanical properties is an important factor influencing the service performance of TiAl intermetallics. In this work, the texture evolution and mechanical anisotropy of extruded Ti–47Al–2Cr-0.2Mo alloy after heat treatment were investigated. The results indicated that α2 phase of extruded TiAl alloy exhibited deformation texture with a {11–20}<10-10> transverse orientation, and recrystallization texture with a {0001}<11–20> basal orientation. The existence of textures resulted in obvious mechanical anisotropy along the extrusion direction (ED) and transverse direction (TD). The {11–20}<10-10> transverse texture was favorable to the activation of basal <a> slip along the ED, however, the {0001}<11–20> basal texture made the prismatic <a> slip easily activated in the TD. After heat treatment in the upper temperature range of (α+γ) region, the mechanical anisotropy was alleviated due to the strengthened {0001}<11–20> basal texture by the oriented recrystallization nucleation. After heat treatment in the single α phase region, the {10-10}<11–20> transverse texture was formed with the oriented grain growth, contributing to the pyramidal <a> slip along the TD.