Interfacial engineering via Cu incorporation: achieving superior wettability and thermal conductivity in AlSi10Mg to graphene brazing

For miniaturized electronics operating in extreme environments such as aerospace applications, solid-state vapor chambers offer excellent temperature uniformity and structural robustness. Aluminum alloy is widely considered an ideal casing material due to its low density and high thermal conductivity. In parallel, graphene film, with its ultra-high thermal conductivity significantly exceeding that of conventional metals, serves as an excellent material yet requires reliable integration with metals. Herein, electrodeposited copper layers were applied to the substrate to address the solder's poor wettability, enabling high-integrity joints with significantly enhanced thermal conductivity. Experimental results demonstrate that this metallization approach significantly increased surface energy, leading to contact angle reductions of 80% on the aluminum alloy and 50% on the graphene film. Furthermore, a joint brazed at 520 °C for 10 minutes exhibited a thermal conductivity of 248.012 W·m -1 ·K -1 .