INTERACTION BETWEEN A SCREW DISLOCATION AND A BIMETALLIC INTERFACE

The external stress required to hold a screw dislocation in equilibrium in a two-phase material formed by joining two dissimilar elastic half-planes is determined using the Peierls model of a dislocation. The displacement field on the slip plane is also obtained when the dislocation is at the interface. The solution to this problem that appears in the literature is based on a singular dislocation model and is valid only when the dislocation is at some distance away from the interface, since the expression for the necessary external stress for equilibrium of the dislocation becomes infinite when the dislocation is at the interface. By taking into consideration the atomic forces on the slip plane, the present work yields a finite value of external stress needed to cause penetration of the barrier and reduces to the known solution for a singular dislocation when the distance of the dislocation from the interface is large. © 1969.