Basal slip of ⟨a⟩ screw dislocations in hexagonal titanium

• DOI: 10.1016/j.scriptamat.2018.11.027
• Publication Date: 2018-11-24T00:35:03Z
• Authors: Piotr Kwasniak; Emmanuel Clouet
• Keywords: Ribbon; Stacking fault; Basal plane

Basal slip of a screw dislocations in hexagonal closed-packed titanium is investigated with ab initio calculations. We show that a basal dissociation is highly unstable and reconfigures to other structures dissociated in a first order pyramidal plane. The obtained mechanism for basal slip corresponds to the migration of the partial dislocations and of the associated stacking fault ribbon in a direction perpendicular to the dissocia-tion plane. Presented results indicate that both basal and pyramidal slip will operate through the Peierls mechanism of double-kink nucleation and will be equally active at high enough temperature.