Creep of dispersion strengthened alloys controlled by jog nucleation

Abstract

The creep behavior of dispersion strengthened materials is generally characterized by unusually high activation energies and stress exponents. In this paper we propose a model in which jog nucleation in the particle-matrix interface is assumed to control dislocation climb and, thus, the creep rate. This approach results in a new creep equation without adjustable parameters which reproduces the high stress exponents and activation energies. Experimental creep data for Al alloys can be described just as well as by the earlier “detachment model”. Because of the different physical basis, new implications for alloy design may be expected.