Ostwald Ripening of the Matrix Phase Surrounding Dispersoids

Self-similar coarsening of particles dispersed in a matrix is well known experimentally and theoretically as Ostwald ripening. In this paper we present experimental and numerical material on Cu–Co dispersions looking for the inverse effect: Does the copper matrix surrounding cobalt particles also coarsen self-similar during liquid phase sintering as the particles do? The experimental investigations were performed with Cu–Co alloys of various volume fractions of solid phase (0.25 to 0.7). Green compacts of both elemental powders were sintered at 1473 K for times between 5 minutes and 70 hours. The coarsening of the matrix was analysed in plane section of the specimens. The experimental results show that the matrix coarsens self-similar. A numerical modelling is presented clarifying the experimental results.