A pileup of screw dislocations against an inclined bimetallic interface

Abstract

A pileup of edge dislocations against an arbitrarily inclined flat bimetallic interface is considered. Equilibrium positions of dislocations are determined for a given number of dislocations and specified material properties, assuming that the resolved shear stress along the pileup plane from a remotely applied loading is uniform and equal for all interface inclination angles. Numerical results are compared for pileups at 0°, 30°, 45°, and 60° relative to the interface normal. The overall dislocation distribution is mildly affected by the inclination of the interface, although there are some notable differences. While an inclined interface repels the first and last dislocation stronger than the orthogonal interface, for piled-up dislocations in-between this is not necessarily the case. Small differences in the pileup length and the proximity of the leading dislocation to differently inclined interfaces can considerably affect the interface stresses. The magnitude of interface stresses decreases with the increase of the shear moduli ratio G2/G1 due to stronger repulsion exerted on dislocations by stiffer interfaces. The disparity in Poisson’s ratio also affects the interface stresses. The back stress behind a trailing dislocation is evaluated and discussed.