The visualized experiments of melting of paraffin wax in open-cell aluminum foam are performed using the microscopical technique and the infrared camera. The phase change process of paraffin wax and fluid flow are revealed in aluminum foam at the pore level

and the thermal performance of the paraffin-aluminum foam composite is visually investigated. The experimental results indicate that the aluminum foam can helpfully enhance phase change heat transfer of paraffin wax

and the wax-aluminum foam composite mainly dominated by the conduction of metal matrix has better thermal performance than the pure wax with clearly melting interface. In addition

several fragments of suspended matters are observed to be existed in the liquid wax.