Effect of diamond particle size on thermal conductivity of diamond/Cu composites fabricated via high-temperature and high-pressure fusion infiltration method

This study explores how diamond particle size affects the thermal conductivity of diamond/Cu composites fabricated via high-temperature and high-pressure (HTHP) fusion infiltration method. Under extreme pressure, diamond particles (100–500 μm) undergo rearrangement and fracture, facilitating the infiltration of molten Cu into interstitial and internal gaps to achieve a diamond volume fraction >90%. The process also induces the formation of amorphous carbon on diamond surfaces, strengthening interfacial bonding. Consequently, diamond/Cu composites prepared via HTHP fusion infiltration method have higher thermal conductivity. A non-linear correlation between particle size and thermal conductivity was observed, with the optimal performance (606.33 W/(m·K)) attained using 200 μm diamond particles.