Abstract: SiC whisker reinforced alumina composites were fabricated by hot-pressing from the commercial γ-Al₂O₃ and SiC whisker made
in Shanghai Institute of Ceramics. We obtained some samples with 30vol% SiCw hot-pressed at 1800℃ in Ar atmosphere having the flexure
strength of 812±38MPa and fracture toughness of 8.8±0.1MPa·m^1/2 at room temperature; 560±61MPa and 6.1±0.4MPa at 1200℃ respectively. The small amount of additions accelerated densification but
reduced the mechanical properties. In N₂ atmosphere, SiC whisker would be injured and the composites mechanical properties degraded. Moreover,
the microstructural observations indicated that the toughening mechanism of AS composites is different from whiskers pull-out and matrix’s cleavage
fracture at room temperature to whiskers/matrix interface debonding and matrix’s intergranual fracture at high temperature.

Key words: whiskers reinforced, composites’ preparation, mechanical properties