Thermal conductivity of diamond particle dispersed aluminum matrix composites fabricated in solid–liquid co-existent state by SPS

Diamond particle dispersed aluminum (Al) matrix composites were fabricated in solid–liquid coexistent state from the powder mixture of diamond, pure Al and 5056-type Al–Mg alloy by spark plasma sintering (SPS) process. Microstructures and thermal conductivities of the composites fabricated were examined. These composites can be well consolidated at 813 K for 0.6 k s and scanning electron microscopy detects no reaction at the interface between the diamond particle and the Al matrix. The relative packing density of the diamond-Al composite fabricated was 97% or higher in a volume fraction range of diamond between 25.5 and 45.5%. The thermal conductivity of the Al matrix composite containing 45.5 vol.% diamond reached 403 W/mK, approximately 76% the theoretical thermal conductivity estimated by Maxwell–Eucken’s equation.