Preparation of ASZ Thermal Storage Ceramics for Solar Thermal Power Generation

摘要

This paper aims to investigate the properties and microstructure of Al_2O_3-SiC-ZrO_2 (ASZ) composite ceramics for solar thermal power generation. The composite ceramics were prepared from α-Al_2O_3, partially stabilized zirconia (Y_2O_3 5.2 wt%) and silicon carbide fired at 1280°C for 2h through pressureless sintering. Influence of the contents of SiC and ZrO_2 on 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·(kg·K)~(-1), 0.01 cm~2·s~(-1), 2.26 W·(m·K)~(-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.