Processing and Characterization of Laminated SiC Whisker Reinforced Al2O3

Laminated silicon carbide (SiC) whisker/alumina (Al2O3) composites were fabricated by tape casting and hot pressing. Whisker loadings of 10 and 20 vol % were produced with a predominance of fiber orientation in the direction of casting. Elastic, thermal and mechanical properties of the composites were measured in the longitudinal and transverse directions. The elastic moduli for 10 and 20 whisker vol% Al2O3 composites were approximately the same as unreinforced alumina. The coefficient of thermal expansion was reduced by the addition of the whiskers. The fracture toughness of the composites increased with whisker content from 3.8 MPa m1/2 for pure alumina to 8.0 MPa m1/2 for 20 vol% whiskers in the longitudinal direction.