Microstructure and thermal conductivity of Cu-B/diamond composites

This article considers the potential of boron as matrix-alloying element and gives perspectives about which content of boron is favorable to maximize the interfacial bonding and thermal conductivity of copper/diamond composites. The thermal conductivity of Cu-B/diamond composites is investigated both experimentally and theoretically. The thermal conductivity measurements show that the optimum boron content at 0.8wt% has provided highest thermal conductivity of 538W/mK, increases 190% compared to that of copper/diamond composite without boron addition. Theoretical models are used to understand the underlying thermal conductivity enhancement mechanisms of matrix alloying. It is found that the Hasselman-Johnson model combined with a modified Debye model considering the carbide thermal resistance can provide a satisfactory agreement to the experimental data.