Effects of Three Silicon-based Raw Materials on Properties and Microstructure of MgO-Al-C Materials

摘要

To improve the thermal shock resistance(TSR)of MgO-Al-C materials,three silicon-based raw materials with low expansion coefficients(Si,fused quartz,and SiC)were introduced to the materials,and their effects on the properties of the materials were studied by XRD and SEM.The results show that:(1)the conversion of Si to SiC,SiO2 and forsterite at high temperatures improves the hot modulus of rupture(HMOR),TSR and oxidation resistance of the materials,and the optimal Si addition is 6 mass%;(2)fused quartz improves the TSR of the materials,but its high temperature softening and crystal transformation are not conducive to the HMOR and oxidation resistance of the materials,and the optimal addition is 2 mass%;(3)the SiC addition improves the TSR,HMOR and oxidation resistance of the materials;however,when the SiC addition exceeds 10 mass%,there are more micro-cracks in the materials,decreasing the TSR and oxidation resistance.