Abstract
A12O3 based composites dispersed with both SiC-whisker and ZrO2 particle were successfully fabricated by hot-pressing. The mechanical properties of these composites were largely improved by the multiple toughening of SiC whisker and ZrO2. Fracture strength 1060MN/m2 and fracture toughness 7.5MN/m3/2 were observed for the A12O3/15vol%SiC whisker/15vol%Zr02 composites. For these composites, the transient-tensile-thermal stresses by rapid quenching technique into water were applied to promote the tetragonal-monoclinic transformation of ZrO2 without increasing the surface flaw. As results, the strength improvement over 30% was realized by the compressive stress associated with the tetragonal-monoclinic transformation of ZrO2 at the near surface which was accelerated by thermal stresses with water quenching after the light grinding with diamond wheel.
