Abstract

The diamond particle size plays a critical role in regulating the thermal conductivity of diamond/Cu composite. However, the dependence of diamond particle size on thermal conductivity is generally interfered with interface carbides, and the effect of diamond particle size on the thermal stability of diamond/Cu composite has not been addressed. In this study, we fixed the thickness of the ZrC interlayer between Cu and diamond at around 60 nm and varied diamond particle size from 54 to 272 μm to investigate the relationship between diamond particle size and composite thermal conductivity. The thermal conductivity of the Zr-diamond/Cu composite increases with increasing diamond size. A high thermal conductivity of 820 W/mK is obtained with a diamond particle size of 272 μm. The thermal conductivities of all composites are decreased after 100 thermal cycles, and the diamond/Cu composite with large diamond particle size shows better thermal stability during thermal cycling. The findings emphasize the importance of tailoring diamond particle size to attain high thermal conductivity in the diamond/Cu composites and provide useful guidelines for their thermal management applications.