Dislocation movement around an inclusion during plastically-accommodated creep at high temperatures

Abstract

Plastically accommodated creep in an inclusion bearing material (particle- or discontinuous fiber-reinforced metal matrix composite) without any interfacial relaxation mechanisms has been examined. For a material with an elastic-viscoplastic matrix, the non-uniform strain rate in steady state creep is derived using Eshelby’s solution for elastic strain outside an inclusion. The obtained creep strain increment is impotent and does not generate any additional internal stress. During this creep deformation, a dislocation comes in from one direction and goes out in another direction, so that no dislocation nor internal stress but a heterogeneous plastic strain remains in the material. The concrete trajectory of the dislocations climbing over a cylindrical inclusion is calculated and illustrated.