Superplastic behavior of regular α2 and super α2 titanium aluminides

Abstract

Superplasticity in two titanium aluminides, regular α 2 and super α 2 were studied at temperatures ranging from 920 to 1040 °C and strain rates from 2 × 10 −5 to 5 × 10 −3 s −1. Results show that superplastic elongations of over 500% can be obtained in this group of intermetallic materials. Dynamic grain growth and changes in volume fraction of the phases were observed in both alloys. The regular α 2 alloy failed mainly by intergranular separation whereas transgranular fracture with extensive ductility occurred in the super α 2 alloy. Possible mechanisms of superplastic deformation of these intermetallic alloys are also proposed.