Tailoring Interface Structure and Enhancing Thermal Conductivity of Cu/Diamond Composites by Alloying Boron to the Cu Matrix



Diamond particles reinforced Cu matrix (Cu/diamond) composites were prepared by alloying 0.1–1.0 wt% B to the Cu matrix in order to tailor the interface structure. The interface structure evolves from discrete triangular carbides into continuous jig-saw carbides depending on the availability of boron source in the Cu-B matrix. We report the highest thermal conductivity of 868 W/mK so far in boron-modified Cu/diamond composites, which originates from the discontinuous carbide interface in the Cu-B/diamond composites. The parallel connection of interfacial thermal resistances of the discontinuous carbide interface reduces the total interfacial thermal resistance and therefore promotes phonon transfer across the Cu/diamond interface. We clarify the formation mechanism of discontinuous carbide interface in the Cu-B/diamond composites and demonstrate the decisive role of discrete triangular carbides in enhancing thermal conductivity of Cu/diamond composites. The results help to establish the method of metal matrix alloying to prepare Cu/diamond composites with high thermal conductivity for thermal management applications. © 2019 Elsevier Inc.



High-resolution electron microscopy, Metallic composites, Thermal conductivity, Mechanical alloying, Boron, Boron compounds, Carbides, Copper alloys, Electric connectors, Jigs


This work is financially supported by the National Natural Science Foundation of China (No. 51571015), the National Key Research and Development Program of China (No. 2016YFB0402102) and the State Key Laboratory for Advanced Metals and Materials (No. 2018Z-27).


©2019 Elsevier Inc.