Dual-dispersion medium derived 3D graphene networks: a strategy to fabricate Cu@Ag/GO composite with optimized performance and suppressed dewetting

Graphene oxide (GO) has emerged as a promising reinforcement material for metal matrix composites due to its exceptional properties. However, achieving homogeneous graphene dispersion within the metal matrix remains a critical challenge that significantly impacts the performance of the composite. In this study, we developed an innovative dual-dispersion medium approach to fabricate Cu@Ag/GO composites. The Cu@Ag particles and GO sheets were dispersed in ethanol in deionized water separately, followed by ultrasonic-assisted mixing and hot-press sintering to create a three-dimensional GO network structure. Experimental results indicate that the dual-dispersion method is conducive to the uniform attachment of GO to the silver-coated copper surface through hydrogen bonding, thereby reducing structural defects and effective effectively inhibiting Ag dewetting. The optimized composite containing 0.2 wt% GO exhibited significantly enhanced sintering properties compared to Cu@Ag: a shear strength of 94.3 MPa (50.2% improvement), thermal conductivity of 240.0 W/(m·K) (60.5% improvement), and reduced electrical resistivity of 4.7 μΩ·cm (38.8% decrease). This facile fabrication method of Cu@Ag/GO composites offers significant potential for developing high-performance die-attach and interconnect materials with superior mechanical strength, thermal transfer, and electrical conductivity for advanced power module applications.