The effect of Al2O3 and (Ti or Si)C additions on various properties of a (Y)TZP (yttria‐stabilized tetragonal zirconia polycrystal)–Al2O3–(Ti or Si)C ternary composite ceramic were investigated for developing a zirconia‐based ceramic stronger than SiC at high temperatures. Adding Al2O3 to (Y)TZP improved transverse rupture strength and hardness but decreased fracture toughness. This binary composite ceramic revealed a rapid loss of strength with increasing temperature. Adding TiC to the binary ceramic suppressed the decrease in strength at temperatures above 1573 K. The residual tensile stress induced by the differential thermal expansion between ZrO2 and TiC therefore must have inhibited the t‐ →m‐ZrO2 martensitic transformation. It was concluded that a continuous skeleton of TiC prevented grain‐boundary sliding between ZrO2 and Al2O3. In contrast, for the ternary material containing β‐SiC in place of TiC, the strength decreased substantially with increasing temperature because of incomplete formation of the SiC skeleton.
|Number of pages||7|
|Journal||Journal of the American Ceramic Society|
|Publication status||Published - 1989 Feb|
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Chemistry