CREEP OF DISPERSION-STRENGTHENED ALLOYS CONTROLLED BY JOG NUCLEATION

The creep behavior of dispersion strengthened materials is generally c haracterized by unusually high activation energies and stress exponent s. In this paper we propose a model in which jog nucleation in the par ticle-matrix interface is assumed to control dislocation climb and, th us, the creep rate. This approach results in a new creep equation with out adjustable parameters which reproduces the high stress exponents a nd activation energies. Experimental creep data for Al alloys can be d escribed just as well as by the earlier ''detachment model''. Because of the different physical basis, new implications for alloy design may be expected. Copyright (C) 1996 Acta Metallurgica Inc.