Microstructure and thermal conductivity of Cu/diamond composites with Ti-coated diamond particles produced by gas pressure infiltration

As an attractive thermal management material, diamond particles reinforced Cu matrix (Cu/diamond) composites generally exhibit thermal conductivities lower than expected. To exploit the potential of heat conduction, a combination of Ti coating on diamond particles and gas pressure infiltration was used to prepare Cu/diamond(Ti) composites. A high thermal conductivity of 716 W/mK and a low coefficient of thermal expansion of 5.8 ppm/K at 323 K were obtained in the composites. Auger electron spectroscopy (AES) characterization shows that a TiC layer was formed between Cu matrix and diamond reinforcement, which is responsible for the enhancement of thermal conductivity. The results suggest that Ti coating can significantly promote interface bonding between Cu and diamond and gas pressure infiltration is an effective method to produce Cu/diamond composites. - Highlights: • The Cu/diamond(Ti) composites are produced by gas pressure infiltration. • A TiC layer is formed between Cu matrix and diamond reinforcement. • A thermal conductivity of 716 W/mK is obtained for the composites. • A coefficient of thermal expansion of 5.8 ppm/K at 323 K was obtained