Preparation of W-Plated Diamond and Improvement of Thermal Conductivity of Diamond-WC-Cu Composite

The tungsten (W)-plated diamond process was explored and optimized. A dense and uniform tungsten coating with a thickness of 900 nm was successfully prepared by the powder covering sintering method. The Diamond-WC-Cu composite with high density and high thermal conductivity were successfully prepared by cyclic vacuum pressure infiltration. The microstructure and composition of the W-plated diamond particles were analyzed. The effect of tungsten coating on the microstructure and thermal conductivity of the Diamond-WC-Cu composite was investigated. After calculation, the interface thermal resistance of the composite forming the tungsten carbide transition layer is 2.11 × 10−8 m2∙K∙W−1. The thermal conductivity average value of the Diamond-WC-Cu composite with a diamond volume fraction of 60% reaches 874 W∙m−1∙K−1, which is close to the theoretical prediction value of Hasselman-Johnson (H-J) model and differential effective medium (DEM) model. Moreover, the Maxwell-Eucken (M-E) model, H-J model, and DEM model were used to evaluate the thermal conductivity of the Diamond-WC-Cu composite.