Microstructure and mechanical properties of SiC whisker reinforced ZrO2 (2 mol% Y2O3) based composites

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