Matrix Grain Size Effect and Fracture Bmamor on Bending Strength and Fracture Toughness in Multi‐Toughened Al2O3

Al2O3 was reinforced with SiC-whisker and SiC-platelet as model material for multitoughening effect. All materials were fabricated by same procedure to neglect the effect of process difference. Grain size distribution was strongly affected by the shape and mass fraction of reinforcement, and the distribution changed fracture style in fracture surface. It was found that bending strength can be evaluated by Petch's law as first-order approximation. Compared with single-toughening composites, fracture toughness was highly improved in multitoughening composite. Deflection by platelet improved fracture toughness in case of fine matrix grain composites, and no interaction between whisker and platelet was observed. 10 refs.