Al/Gf composite foams with SiC-engineered interfaces for the next generation of active heat dissipation materials

Abstract

Interfacial engineering has been investigated as a method of increasing thermal conductivity in a variety of aluminium/graphite composites but remains unexplored in the few graphite-containing aluminium foams developed to date. In this study, the replication method was used to fabricate aluminium/graphite composite foams by infiltrating with liquid aluminium packed preforms containing SiC-coated oriented graphite flakes and NaCl particles, the latter acting as a templating agent. The effects of interfacial modification caused by the SiC presence were investigated alongside those of NaCl and graphite flake particle sizes. Materials benefit from low pressure drops when large NaCl particles are used. Furthermore, large graphite flakes coated with SiC provide thermal conductivities up to 232 Wm-1K-1, improved mechanical properties and power dissipation capacities up to 2-fold and 6-fold higher than aluminium/graphite composite foams with unmodified interfaces and standard aluminium foams, respectively, making them ideal candidates for active heat sinks in next-generation electronic devices.