Thermal Properties of Al/Diamond Composites Fabricated in Continuous Solid-Liquid Co-Existent State by SPS

Abstract

Diamond-particle-dispersed-aluminum (Al) matrix composites were fabricated in continuous solid-liquid co-existent state by spark plasma sintering (SPS) process from the mixture of diamond powders, pure Al powders and Al-5mass%Si alloy powders. The microstructures and thermal conductivities of the composites fabricated were examined. These composites were well consolidated by heating at a temperature range between 798K and 876K for 1.56ks during SPS process. No reaction at the interface between the diamond particle and the Al matrix was observed by scanning electron microscopy for the composites fabricated under the sintering conditions employed in the present study. The relative packing density of the diamond-Al composite fabricated was 99% or higher in a volume fraction range of diamond between 45% and 50%. Thermal conductivity of the diamond-Al composite containing 50 vol.% diamond reached 552W/mK, approximately 95% the theoretical thermal conductivity estimated using Maxwell-Eucken’s equation.