OSTWALD RIPENING OF LIQUID-PHASE SINTERED CU-CO DISPERSIONS AT HIGH-VOLUME FRACTIONS

An experimental study on the influence of a finite volume fraction of solid on Ostwald ripening of Cu-Co dispersions is presented. Cu-Co all oys with volume fractions of solid Co-particles in the range From 0.25 to 0.7 were annealed at 1473 K for times between 5 min and 70 h such that the Co particles coarsened within a liquid Gu(Co) matrix. The coa rsening of the Co-particles was analyzed by various image analysis met hods to yield statistically significant results. The experimental resu lts on the coarsening rate and the particle size distribution as they vary with volume fraction are presented. The results show that there i s not a definitive effect of the volume fraction on the rate of coarse ning and that in all cases investigated the size distributions are bro ader than predicted by any theory of Ostwald ripening. (C) 1998 Acta M etallurgica Inc.