Paper detail

Stacking faults and the γ-surface on {1-101} pyramidal planes in α-titanium

Using first principles methods we calculated the entire γ-surface of the first order pyramidal planes in α-titanium. Slip on these planes involving dislocations with c + a dislocations is one means by which α-titanium polycrystals may supplement slip on prism planes with a-type Burgers vectors to maintain ductility. We find two stable intrinsic stacking faults with relatively small energies. We show that dissociation of c + a dislocations into two dislocations with Burgers vectors (c + a)/2 is not possible in α-titanium because there is no stable stacking fault at (c + a)/2. Instead we propose a possible dissociation of a c + a dislocation into three partial dislocations separated by the two intrinsic faults we have identified.