Preparation of ASZ Thermal Storage Ceramics for Solar Thermal Power Generation

Abstract

This paper aims to investigate the properties and microstructure of Al2O3-SiC-ZrO2(ASZ) composite ceramics for solar thermal power generation. The composite ceramics were prepared from α-Al2O3, partially stabilized zirconia (Y2O35.2 wt%) and silicon carbide fired at 1280 °C for 2 h through pressureless sintering. Influence of the contents of SiC and ZrO2on the performance of ASZ composite ceramics have been observed and extensively investigated via XRD, SEM, etc. The results revealed that the thermal shock resistance and high-temperature thermal properties would increase with the increase of the SiC content. No cracking occurred after 30 times thermal shock (from room temperature to 800°C with air cooling) while the bending strength after thermal shock test, the thermal expansion coefficient, the heat capacity, the thermal conductivity coefficient and the thermal conductivity were 76.99MPa (with a growth rate of 27.89% after thermal shock), 5.85×10-6°C-1, 1.05 kJ(kgK)-1, 0.01 cm2s-1, 2.26 W(mK)-1, respectively. The XRD patterns indicated that the main crystal phases included corundum, silicon carbide and zirconium silicate while the SEM images illustrated the well-grown crystal grains had the sizes distributed among 5-120 μm.Key words: Al2O3-SiC-ZrO2composite ceramics, Silicon carbide, Thermal properties,Microstructure, Solar thermal power generation