Coarsening of particles connected by dislocations

Abstract

This work theoretically reinvestigates the coarsening of particles controlled by diffusion through a dislocation network, when the dislocation spacing of the network is larger than the maximum particle size and the volume fraction of the particles vanishes. Both a three-dimensional network and a plane one, such as that which might be encountered at a low-angle grain boundary, are treated. It is considered here that the number of dislocation pipes for diffusion increases with distance away from the particle. Under certain reasonable assumptions, at ^1/4 steady-state coarsening kinetics is found. The origin of the differences between the present kinetic results (t^1/4) and those predictions previously reported in the specialized literature (t ^1/5), for similar dislocation geometries, are discussed. The effect of the dislocation annihilation phenomenon on the growth kinetics is also examined qualitatively.