Superplastic behavior of regular α2 and super α2 titanium aluminides

Abstract

Superplasticity in two titanium aluminides, regular α2 and super α2 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 α2 alloy failed mainly by intergranular separation whereas transgranular fracture with extensive ductility occurred in the super α2 alloy. Possible mechanisms of superplastic deformation of these intermetallic alloys are also proposed.