Ultrasonic vibration enabled cold manufacturing of high thermal conductive Cu/Diamond composites
The escalating thermal management demands of modern electronics necessitate materials with superior thermal conductivity and matched thermal expansion. Cu/Diamond composites are promising, yet their fabrication typically requires extreme conditions (high temperature/pressure) or complex coating processes. This work introduces a one-step, heat-source-free cold manufacturing method using ultrasonic vibration to consolidate Cu/Diamond composites at room temperature and a low pressure of ~16 MPa within seconds. The applied pressure is reduced by 200–500 times, and the required temperature is only 20% of that used in conventional high-temperature high-pressure sintering. Direct metallurgical bonding at Cu-Cu interfaces and solid embedding of diamond particles in the Cu matrix are achieved, yielding a composite with a high yield strength of 150 MPa. The method enables a maximum diamond proportion of ~60%, resulting in a thermal conductivity exceeding 1043 W/(m·K) and a coefficient of thermal expansion below 10×10⁻⁶ K⁻¹. Complex shapes are readily fabricated, and heat dissipation tests demonstrate superior performance compared to commercial Al₂O₃ and AlN substrates. The loose preparation conditions and rapid processing confer significant industrial production potential.