Abstract
Diamond-particle-dispersed-copper (Cu) matrix composites were fabricated by spark plasma sintering (SPS) process from the mixture of diamond particles, pure-Cu and chromium (Cr) powders. The microstructures and the thermal conductivities of the composites fabricated were examined. These composites were all well consolidated at a temperature of 1173K for 600s by SPS process. No reaction at the interface between the diamond particle and the Cu matrix was observed by scanning electron microscopy and X-ray diffraction analysis for the composites fabricated under the sintering conditions employed in the present study. The relative packing density of the diamond particle dispersed Cu matrix composites with Cr addition was 4.4~5.9% higher than that without Cr addition. The thermal conductivity of the Cu/diamond composite drastically increased with Cr addition. The thermal conductivity of (Cu-Cr)-50 vol% diamond composites was 518~584 W/mK in a volume fraction range of Cr between 2.5 and 8.6 vol% in Cu matrix. Numerous transgranular fractures of diamond particles were observed on the bending fracture surface of diamond particle dispersed Cu matrix composites with Cr addition, indicating strong bonding between the diamond particle and the Cu matrix in the composite.
