Multi-scale design of novel materials for emerging challenges in active thermal management: Open-pore magnesium-diamond composite foams with nano-engineered interfaces

Abstract

Open-pore Mg foams, which have been traditionally discarded for heat dissipation applications given their low thermal conductivity values, can prove appealing materials for active thermal management if they incorporate diamond particles coated with a nano-dimensioned layer of TiC. These composite foam materials can be manufactured by the replication method, conveniently adapted to Mg, that requires a strict multi-scale control: correct distribution of structural constituents (pores, diamond and Mg) on the meso-/micro-scale ensures homogeneity and complete pore connectivity, while a proper nanoscale control of the TiC coating on diamond particles achieves high thermal conductance at the interface between diamond particles and Mg. The manufactured Mg-diamond foam materials attain outstanding thermal conductivity values (up to 82 W/m K) and maximum heat dissipation performance, tested on active convective cooling, almost two times higher than their equivalent magnesium foams and twenty per cent superior to that of conventional aluminium foams.