Preparation and Properties of Mullite-SiC-Sialon Composite Refractories

摘要

Mullite-SiC-Sialon composite refractories were prepared using mullite,β-SiC,Si and Al2O3 as starting materials by nitridation reaction sintering.The phase transformation and microstructure of the products were investigated by XRD,SEM and EDS.The strength and thermal shock resistant of the composites refractories have been determined at room temperature.The results show that the main phases in the composite refractories contain mullite,β-SiC and Si3Al3O3N5.With the increase of Si powder addition,both the bulk density and flexural strength of the samples increase.When the addition of Si powder is 12 mass％,the sample has better properties with density of 2.13g·cm-3,flexural strength of 40.08 MPa,and residual flexural strength of 28.09 MPa after 5 times thermal shock resistance test at 1200 °C.