Thermal analysis of Al-Si alloys as high-temperature phase-change material and their corrosion properties with ceramic materials

This study reports the thermal analysis of Al-Si alloys as candidate high-temperature phase-change materials (PCM) for temperatures above 500 °C and the corrosion behavior of the alloys with ceramic materials. Four Al-Si alloys with different Si contents (0-25 wt%) were selected as PCMs. Engineering ceramics such as Al2O3, AlN, Si3N4, SiC, and SiO2 were used for corrosion tests. Thermal analysis showed that the Al-Si alloys were better than conventional molten salts as PCM candidates because of the high heat storage capacity and high thermal conductivity of the alloys. The corrosion tests revealed that Al2O3, AlN, and Si3N4 showed high corrosion resistance to molten Al-Si alloys; therefore, these ceramics were suitable as structural materials for a latent heat storage (LHS) system using Al-Si alloys. These results demonstrate the feasibility of high-temperature LHS systems using Al-Si alloys as the PCMs and ceramics as structural materials.