Effects of oxygen on prismatic faults in α-Ti: a combined quantum mechanics/molecular mechanics study

The mechanical properties of α-Ti are greatly affected by the presence of oxygen impurities. Here we focus on the interaction of oxygen with prismatic faults and oxygen diffusion barriers in α-Ti using a multiscale quantum mechanics/molecular mechanics approach. We show that a one-sixth monolayer of oxygen addition increases the Peierls stress 4-fold and reduces the dislocation core width by 18%. The calculated hardening effect due to oxygen and the oxygen diffusion barriers are consistent with experiments.