MICROSTRUCTURE AND MECHANICAL-PROPERTIES OF SIC WHISKER-REINFORCED ZRO2 (2-MOL-PERCENT Y2O3) BASED COMPOSITES

Microstructure, mechanical properties and toughening mechanisms of hot -pressed SiC whiskers (SiCw) reinforced ZrO2 (2 mol% Y2O3) based compo sites were investigated by using TEM, SEM and XRD techniques and mecha nical tests. It was shown that the Vickers hardness: elastic modulus, fracture toughness and flexural strength of ZrO2(2Y) ceramics are obvi ously improved by the addition of SiCw. TEM observations showed that w hiskers and the ZrO2 matrix are bonded tightly and there is no obvious second phase formed on the SiCw/ZrO2 interface. Both whisker tougheni ng and transformation toughening are effective in ZrO2 (2mol% Y2O3) ce ramics so that a good combination of high strength and high fracture t oughness can be obtained.