Microstructure of nano SiC dispersed Al2O3-ZrO2 composites

Nano-sized SiC dispersed YSZ (3 mol% Y2O3-ZrO2)-Al2O3 composites were fabricated by hot-pressing of SiC/YSZ/Al2O3 mixture and it was investigated the dispersed effect of nano SiC particles on suppression of grain growth as a function of hot-pressing temperature in the range of 1000-1800 °C. The SiC particulates were dispersed within the alumina grains and at grain boundaries. SiC particles significantly inhibited grain growth of the Al2O3 matrix. Significant grain growth was observed above 1600 °C for pure alumina and above 1700 °C for the YSZ-Al2O3 composites. In contrast, significant grain growth of the alumina matrix in the SiC-YSZ-Al2O3 composites did not occur due to the disturbance of grain boundaries migration by immobile nano SiC.