Atomistic modeling of dislocation interactions with twin boundaries in Ti

Dislocation/ boundary interactions play a prominent role in mechanical properties and plastic deformation of materials. We study the interaction between prismatic screw a , prismatic edge c and pyramidal mixed c+ a dislocations with ( 1011) and (1013) twin boundaries in titanium using atomistic simulations. Details of the dislocation reactions depend on the slip system, atomic structure of boundary and stress/ strain states. All interactions lead to nucleation of twinning dislocations on both twin boundaries, confirming that the interaction with incoming dislocations is a twin growth mechanism. In addition, dissociation of c and c+ a . dislocations on the (1013) results in nucleation of a (1012) ( tension twin) embryo in the second grain- a new twin nucleation mechanism for (1012) twins as a result of c and c + a slip.