Enhanced thermal conductivity of hot-pressed copper/diamond composites with titanium-modified interface

Achieving optimal thermal conductivity and mechanical strength is essential for copper/diamond composites designed for advanced thermal management applications. This study investigates the fabrication of copper/diamond composites via hot-pressing, employing two interfacial engineering strategies: titanium carbide formation through diamond surface metallization and copper matrix alloying with titanium additives. The results show that diamond metallization shows a better effectiveness in enhancing both mechanical and thermophysical performance than matrix alloying. Notably, Cu/50 vol% Ti-coated diamond composite fabricated at 540 MPa achieved an exceptional thermal conductivity of 565 W/mK and a tensile strength of about 147 MPa. For the copper-Ti/diamond composite containing 0.5 wt% Ti processed at 1050 °C, it exhibited a comparable thermal conductivity (554 W/mK), but a relatively low tensile strength (93 MPa). The optimal processing pressures for maximizing thermal conductivity and mechanical strength in hot-pressed Cu/Ti-coated diamond composites differ due to interface microstructure: continuous interface enhances mechanical strength through strong interfacial bonding, whereas jagged interface arranged in parallel on the diamond surface minimizes interfacial thermal resistance. These findings provide valuable guidance for interface design in copper/diamond composites and demonstrate the potential of Ti-coated diamond particles for achieving high-performance materials in thermal management applications. • Hot-pressed copper/diamond composites were fabricated with Ti-modified interfaces. • A continuous TiC interface strengthened interfacial bonding but raised interfacial resistance. • Ti-coated diamond demonstrated superior effectiveness over copper matrix alloying for optimizing the composites' performance. • Thermal conductivity (565 W/mK) and tensile strength (147 MPa) were achieved in 540HP-Cu/50Ti-D though the optimized fabrication process.