Thermal conductivity of PM Cu/diamond composites depending on the chromium content - prediction and characterization

To meet the need of high performance thermal management materials in the field of electronic application heat sink materials reinforced with synthetic diamonds have been prepared via powder metallurgy. A matrix of a copper alloy with a chromium content between 0 and 1.3 wt.% was chosen in order to predict the thickness of the final carbide layer. The volume content of the diamonds, the diamond size and the solubility of chromium in the copper matrix were considered. The mixed powders were consolidated by Spark Plasma Sintering (SPS). The maximum thermal conductivity of 680 W/(mK) measured at room temperature was obtained at a Cr content of 1.07 wt.%.. This is in good agreement with the prediction and corresponds to a continuous carbide layer thickness of ca. 180 nm.