Oxidation Behaviors of MgAlON/Si₃N₄ Composite at High Temperature

Abstract

The isothermal oxidation behaviors of MgAlON/Si3N4 composite which was synthesized by pressureless nitridation reaction sintering have been investigated in flowing air at 1100°C, 1200°C and 1300°C respectively. The results show that the composite represents excellent self-healing property of oxidation at 1300°C, which might be attributed to the formation of protective silicate film with reasonable viscosity, good spreading power and very low oxygen diffusion coefficient, and to the formation of compact surface resulted from the expansion effect of forming mullite from SiO2 and Al2O3. However, the self-healing property of it is relatively poor at 1100°C and 1200°C as compared to 1300°C.