Microstructure of nano SiC dispersed Al₂O₃-ZrO ₂ composites

Nano-sized SiC dispersed YSZ (3 mol% Y₂O₃-ZrO ₂)-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-Al ₂O₃ 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.