Cold-rolling and recovery behaviours of Ti3Al Single Crystals with D019 structure

Abstract

Effects of activated slip systems, rolling direction and chemical composition on cold-rolling behaviours were investigated in Ti3Al single crystals containing 25.0 at% Al and 33.0 at% Al with the D019 structure. Work-hardening and deformability of Ti3Al depended strongly on the operative slip systems. When the rolling axis and rolling plane was controlled to operate dominantly prism slip of {101̄0} <12̄10>, Ti-25.0at%AJ single crystals could be cold-rolled to about 60% reduction in thickness accompanied by gradual work hardening. However, activation of slips on (0001) and {112̄1} pyramidal planes induced strong work-hardening resulting in poor ductility. Deformability of Ti3Al was influenced by chemical composition and the best deformability was obtained at the stoichiometric composition. Annealing after heavy cold-rolling resulted in the occurrence of polygonisation. A Ti3Al sheet was obtained by a thermo-mechanical process combining cold-rolling with annealing.