Abstract: Al₂O₃-SiC composite powders including different size SiC particles were prepared by the heterogeneous precipitation method. The TEM
morphology of Al₂O₃ coating SiC particles was observed. Dense bodies were obtained by hot pressing. SEM observation showed, the Al₂O₃
matrix grain size became smaller with the addition of smaller size SiC particles, but the reduction trend was not as strong as Zener expected. The mechanical properties
of nanocomposites increased when the size of SiC inclusion became smaller, which was relative to smaller weakening effect of SiC particles on matrix
grain and smaller matrix grain size.

Key words: nanocomposites, particle size, alumina, silicon carbide, mechanical propertie