Effects of the Z Value on the Properties of β-Sialon/ZrO2 Composites

beta-Sialon/ZrO2 composites were prepared using 10 wt. % beta-Sialon powder (where the z=1, 2, 3, respectively) and 90 wt. % ZrO2 powder as the starting materials. The effects of the Z value of beta-Sialon on the bulk density, apparent porosity, water absorption rate, room temperature modulus of rupture, thermal shock resistance, microstructure and composition of the composites were investigated. The microstructure of sintered specimens was analyzed by scanning electron microscope (S EM), and X-Ray diffraction (XRD). The results revealed that with increase of the Z value of beta-Sialon, bulk density gradually increased, apparent porosity and water absorption rate gradually decreased. The specimen possessed a maximum MOR (71.46MPa) when the z=2. In carbon embedded condition, the residual strength ratio of the specimen reached 60% and the lowest thermal expansion rate was obtained (0.55%) when the z=1. The phase compositions were cubic ZrO2 (c-ZrO2) and monoclinic ZrO2 (m-ZrO2). beta-Sialon/ZrO2 composites exhibited overall optimum performance when the z equals 2.