High temperature oxidation properties of Al-Cu-Si alloys for latent heat energy storage

Abstract

The effect of Cu content on the high temperature oxidation properties of the phase change material (PCM) Al-Cu-Si alloys was studied. The oxidation kinetics curves at 600℃ were achieved for Al-Cu-Si alloys with 35–55% Cu, which all follow the cubic law. With an increase in the Cu content from 35 to 55%, the weight gain decreases from 5.75 to 3 × 10−4 g/cm2 after 96 h isothermal oxidation. The oxidation rate also decreases with Cu content, the maximum and minimum rates are 1.52 and 0.32×10−5 g/cm2•h, a nearly 4 times difference. Oxidation does not change the phase composition of Al-Cu-Si alloys, but coarsens the microstructure. The latent heat and the starting temperature of phase change after 96 h oxidation at 600℃ have variations of less than 10% and 6℃, respectively, indicating that the Al-Cu-Si alloys have good thermal stability after high temperature oxidation.

Keywords

• Al-Cu-Si alloy
• PCMs
• Oxidation properties
• Thermal stability