Liquid-phase-sintered (LPS) SiC ceramics represent a new class of microstructurally toughened structural materials. In order to understand better the microstructural evolution in these ceramics, the coarsening kinetics in LPS alpha-SiC, containing a yttrium aluminum garnet (YAG) based liquid phase, was studied. It was confirmed that the coarsening occurs primarily by solution-reprecipitation (Ostwald ripening). Most importantly, the SiC grains were found to be faceted in nature, and the coarsening rate was found to be independent of the vol. liquid in the system or the average diffusion path length. Based on these observations it is inferred that interface-reaction controls the solution-reprecipitation coarsening in LPS SiC. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights received. References: 32
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