Optimisation of high thermal conductivity Al/diamond composites produced by gas pressure infiltration by controlling infiltration temperature and pressure

Abstract

In this study, Al/diamond composites were fabricated by the gas pressure infiltration method. The infiltration temperature and pressure were varied to study their influence on the interfacial microstructures and thermal conductivities of composites. The results show that the infiltration temperature and pressure dramatically affect the reaction between the Al matrix and the diamond particles. The appropriate conditions activate the reaction on the {111} faces of diamond which possesses a higher chemical stability than the {100} faces. The course of the reaction can lead to the structural and chemical modification of the interface, which strongly affects the thermal conductivity of the final composites. Using our optimised parameters of 800 degrees C and 0.8 MPa, a superior thermal conductivity above 760 W m(-1) K-1 was obtained. Controlling the fabrication parameters to optimise the reaction on the {100} and {111} faces can result in a superior Al/diamond material with greater thermal conductivity.