High-temperature stability of Cu-20Si alloy-corundum ceramic composite thermal storage materials

High-temperature stable thermal storage materials are urgently needed to meet the demand for solar thermal power generation. Herein, Cu-20Si alloy-corundum ceramic composite thermal storage materials are prepared. The thermal storage performance of the composite, and the erosion resistance of ceramic matrix to alloy are investigated during high-temperature (1000 degrees C) service for 1000 h. The results show that the latent heat of Cu-20Si alloy is increased by 130.76 % to 201.2 kJ/kg compared with the original. Meanwhile, the alloy forms a dense transition layer on the ceramic matrix surface by melting and spreading. Furthermore, the ceramic matrix shows superior erosion resistance to the alloy, owing to the dense structure of ceramic and no chemical reactions between the alloy and ceramic matrix. Finally, test results of long-time service confirm the stability of the composite, which can be used stably for high temperature thermal storage.