Coarsening and grain growth in sintering of two particles of different sizes

Coarsening during sintering results from surface motion, while grain growth results from grain boundary motion. The sintering of two spherical particles of different sizes, and subsequent coarsening and grain growth, were studied until the smaller particle disappeared. When the grain boundary mobility M-gb was comparable to the surface mobility M-s, the curved grain boundary migrated out of the smaller particle in a shorter time with increasing ratio of grain boundary energy gamma(gb) to surface energy gamma(s). As long as the grain boundary was anchored to the surface triple junction, the grain boundary was approximated to be flat at the limit of M-gb much greater than M-s. The motion of flat grain boundary was affected by gamma(gb)/gamma(s), in a different way to that of the curved grain boundary. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.