HOMOGENEOUS FABRICATION OF AL2O3-ZRO2-SIC WHISKER COMPOSITE BY SURFACE-INDUCED COATING

Al2O3-ZrO2-SiC whisker composites were prepared by surface-induced coating of the precursor for the ZrO2 phase on the kinetically stable colloid particles of Al2O3 and SiC whisker. The fabricated composites were characterized by a uniform spatial distribution of ZrO2 and SiC whisker phases throughout the Al2O3 matrix. The fracture toughness values of the Al2O3-15 vol% ZrO2-20 vol% SiC whisker composites (approximately 12 MPa.m1/2) are substantially greater than those of comparable Al2O3-SiC whisker composites, indicating that both the toughening resulting from the process zone mechanism and that caused by the reinforced SiC whiskers work simultaneously in hot-pressed composites.