Abstract: The hot-pressing temperature, matrix grain size, fracture mode and the distribution of SiC were studied to reveal the effect of SiC inclusions on the microstructure
of Al₂O₃. Al₂O₃-SiC composite powder was perpared by the precipitation method. Nano SiC particales were coated with Al₂O₃. After hot pressing,
most of nano SiC particles were randomly located in Al₂O₃ grains. SiC inclusions raised the hot～pressing temperature, decreased Al₂O₃ grain
size, and inhibited the abnormal grain growth of Al₂O₃. The intergranular fracture for Al₂O₃ was transformed to the intragranular fracture for Al₂O₃-SiC
nanocomposites because of the addition of SiC. All those microstructure changes would benefit the improvement of the mechanical properities of Al₂O₃.

Key words: alumina, nanocomposites, silicon carbide, microstructure