Fabrication and characterisation of ZrO2-reinforced porous mullite ceramics

Abstract

ABSTRACT ZrO2-reinforced porous mullite ceramics were fabricated by a foam-gel casting approach using zircon (ZrSiO4) powders and alumina (Al2O3) powders as raw materials. The influence of firing temperature on the phase composition of porous samples was analysed. Based on the analysis results, the effects of a blowing agent on the physical properties, microstructure, mechanical strength and heat conductivity of ZrO2-reinforced porous mullite samples fired at 1600°C were investigated. In the present study, linear shrinkage, porosity and mean pore size of ZrO2-reinforced porous mullite ceramics increased, and volume density, mechanical strength and heat conductivity decreased. When the dosage of the blowing agent was 1.0 vol.-%, the flexural strength and compressive strength of ZrO2-reinforced porous mullite sample with 77.4% porosity respectively reached 3.0 and 10.9 MPa, and their heat conductivity was kept at 0.181 W m−1 K−1.