Screw dislocations interacting with a coated inhomogeneity containing two imperfect interfaces

Abstract

The interaction between screw dislocations, which are located at arbitrary points inside either the matrix or the inhomogeneity, and a circular coated inhomogeneity with two imperfect interfaces is investigated. The explicit solutions of the stress fields and strain energy are derived. With the aid of the Peach–Koehler formula, the explicit expressions of the image forces acting on the dislocations are derived for some cases. The mobility of the screw dislocation in the matrix is discussed for variable parameters (interface imperfection, material mismatch and dislocation position) and the influence of the nearby dislocations is also considered. The attractive force acting on the screw dislocation produced by the imperfect interfaces will increase with the increment of the degree of the interface imperfection. In addition, the mobility and stability of the screw dislocation are strongly influenced by nearby dislocations. The basic solutions provided in this paper can be used as Green's functions to solve the problem on the interaction between arbitrary shape crack and a coated inhomogeneity with imperfect interfaces. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)