Exploring the Interface Structure on Interfacial Thermal Conductivity by Constructing Sandwich-like Cu/Diamond Slice/Cu Composite

The structure and composition of interfacial carbide layer play a key role in the thermal conductivity of diamond/Cu composites; therefore, exploring the regulation method of carbide layer and its influence on interface thermal conductivity (ITC) was very important for the design and synthesis of diamond/Cu composites. In this article, diamond slice was applied, and sandwich-like copper/diamond slice/copper (Cu/DiaS/Cu) composites were designed to obtain more accurate results. Tungsten carbide layer on the diamond surface was fabricated by a thermal diffusion method. A simplified series model of thermal resistance was utilized to obtain the experimental ITC. With the increase of thermal diffusion temperature, thickness of the coating layer increased and WC was produced at 1100°C. The interfacial layer consisting of 501 nm W and 40 nm WC obtained by thermal diffusion at 1100°C for 150 min showed the best thermal properties, with an ITC of 10.16 MW m −2 K −1 . After annealing at 1150°C for 150 min and 240 min, WC content increased while ITC decreased. The phase composition and thickness of tungsten coating layer significantly impacted the heat transfer between diamond and Cu matrix, a small amount of WC in the layer showed the highest ITC.