Graphene is widely used as a barrier at the solid–solid and gas–solid state interface. However, the use of graphene as a barrier at the liquid–solid interface has been rarely reported, particularly in the case of a liquid-state metal and a solid-state metal interface. Herein, a graphene layer is synthesized on a Cu foil, and single-layer and bilayer graphene is detected via Raman spectroscopy. The interfacial intermetallic compound between eutectic Sn–58Bi alloy with a melting temperature of 138 °C and Cu with a melting temperature of 1085 °C can be significantly suppressed by graphene using different reflow temperatures (180°C and 300°C) and reflow times (144–625 s). Cu diffusion through graphene is visible in the Sn–Cu intermetallic compound (IMC) formations in the SB58 solder and at the interface after the reflow processes. We found that the activation energy of Cu diffusion through graphene into the liquid-state graphene is ∼32.6 kJ/(mol∙k), which is higher than that attained without graphene. Therefore, the findings of this study show that graphene is a promising diffusion barrier for the liquid–solid interface.

石墨烯被广泛用作固-固和气-固界面的屏障。然而，很少有报道使用石墨烯作为液固界面的屏障，特别是在液态金属和固态金属界面的情况下。在此，在铜箔上合成石墨烯层，并通过拉曼光谱检测单层和双层石墨烯。使用不同回流温度（180℃和300℃）和回流时间的石墨烯可以显着抑制熔化温度为138℃的共晶Sn-58Bi合金和熔化温度为1085℃的Cu之间的界面金属间化合物（144–625 秒）。在 SB58 焊料中的 Sn-Cu 金属间化合物 (IMC) 形成中以及回流工艺后的界面处，可以看到通过石墨烯的 Cu 扩散。我们发现铜通过石墨烯扩散到液态石墨烯的活化能为 ~32.6 kJ/(mol∙k)，高于没有石墨烯的情况。因此，这项研究的结果表明，石墨烯是一种很有前途的液固界面扩散屏障。