Enhancement of thermal conductivity in diamond/Al composites through vacuum-pressure thermal diffusion sintering

Abstract Improving the thermal conductivity of diamond-metal composites has always been a significant challenge in the field of thermal management. In this paper, diamond/Al composites were systematically studied, and the influence of holding time (10-120 min) on interface structure and thermal conductivity was discussed. The research results shows that the long-term thermal diffusion sintering can effectively the dense interfacial bonding of diamond/Al composites and enhance the thermal conductivity. The diamond/Al composites with 50 vol% 900 μm diamond attained the highest value of 888.73 W/mK under the sintering conditions of 650 ℃, 50 MPa, and 120 min, nearly 92% of the theoretical value predicted by the Maxwell model. This study establishes that high thermal conductivity can be achieved through long-term thermal diffusion alone, without the complex diamond surface coating and substrate alloying.