Interface characteristics and their effects on the heat transfer behavior and mechanical properties of CVD diamond/Cu brazed joint

The thermal conductivity and mechanical properties of CVD diamond/Cu joint have always been the focus of attention in the preparation of diamond microwave windows. In this study, a CVD diamond/Cu joint with excellent thermal conductivity of 539 W/m·K and shear strength of 238 MPa was prepared by using Ag-Cu-In-Ti braze interlayer. The evolution of interface characteristics and heat transfer mechanism of joint were studied in detail. The results showed that the diamond interfacial thermal conductivity is greatly enhanced by the continuous nano TiC interlayer. Meanwhile, by adjusting the brazing temperature to eliminate the seam defects and obtain the appropriate width of seam and diffusion zone, it is also helpful to improve the joint performance. The high temperature performance of joint was also characterized, the thermal conductivity and shear strength of joint remained at 499 W/m∙K and 160 MPa respectively at 400 °C. The research is expected to provide reference for the preparation of diamond/metal joints with high thermal conductivity and bonding strength.