Experimental investigation of the melting performance of a low porosity metal foam/PCM composite heat sink in various configurations

Thermal management is crucial in achieving optimum performance of electronics, reliability, and life. To provide a higher heat dissipation rate over the electronics, metal foam/phase change material (PCM) composites with relatively low porosity have been experimented with in previous efforts. This study aimed to test the thermal performance of metal foam/PCM composite heat sink configurations under a constant heat load. Regular opencell Al and Al6082-based metallic foams with relatively low-porosity values of 25% to 78%, and pore sizes of 8, 10, and 12 mm were manufactured by the casting method using spherical NaCl space holders. The n-eicosane and the Rubitherm RT-42 were used as PCM. The thermal performance of heat sink configurations was presented through transient temperature history, the solid-liquid interface progress, the safe operating time, and thermal resistance. The results showed that the relatively low-porosity foam configurations with various pore sizes have considerable potential for electronics cooling. The safe operating time of the Al foam/n-eicosane composite heat sink with a porosity of 72% and pore size of 8 mm was obtained as high as 1328 s (22.13 min) with about 380% improvement compared to the heat sink without foam. Al foam and n-eicosane perform better than Al6082 and RT-42, respectively. It is noted that lower thermal resistance and higher safe operating times are achieved for heat sink configurations with higher porosity and smaller pore sizes.