Mechanical properties of β-Si₃N₄ whisker reinforced α′-SiAlON ceramics

Abstract

The effects of β-Si₃N₄ whisker additions on the mechanical properties of α′-SiAlON ceramics were studied. The room temperature fracture toughness and fracture strength of the composites increased with increasing whisker content, and were 6.5 MPa m^1/2 and 900 MPa, respectively, for the addition of 30 vol% whiskers. Although creep resistance of the composites was not enhanced at 1200°C, the whisker additions were observed to be beneficial in reducing the oxidation induced slow crack growth of α′-SiAlON that occurred at 1300 °C, and thereby, improved the creep resistance of the composites at 1300°C.