In this study, Cu nanoparticles-coated graphene nanoplatelets (Cu-NPs@GNPs) were synthesized by a simple in situ method with the assistance of NaCl templates and used for reinforcing Al–10Si composites through stir casting process. The experimental results showed that the coating of Cu-NPs on the GNPs could compromise the density mismatch between GNPs and metal matrix and effectively hinder the float of GNPs during stirring. The reaction of Cu-NPs and Al matrix could protect the structural integrity of GNPs as well as improve the interfacial wettability between GNPs and the matrix, thus promoting the uniform dispersion of GNPs in the composites. As a result, the as-prepared 0.5 wt% Cu-NPs@GNPs/Al–10Si composite exhibited a tensile strength of 251 MPa (45% higher than the Al–10Si) with a total elongation of 15%. The strengthening effects were mainly attributed to the following three reasons: Firstly, the Cu-NPs coating improved the interfacial bonding between GNPs and Al matrix which promoted the load transfer from the matrix to the GNPs. Secondly, the nanoscale Al₂Cu formed by the reaction of Cu-NPs and Al matrix played a role in precipitation strengthening. Thirdly, GNPs refined the silicon phases and improved the monolithic performances of the composites.

在这项研究中，在NaCl模板的帮助下，通过简单的原位方法合成了包覆有Cu纳米颗粒的石墨烯纳米片（Cu-NPs @ GNPs），并通过搅拌铸造工艺将其用于增强Al-10Si复合材料。实验结果表明，在GNPs上包覆Cu-NPs可以解决GNPs与金属基体之间的密度失配，并有效地抑制了搅拌过程中GNPs的漂浮。Cu-NPs与Al基体的反应可以保护GNPs的结构完整性，并改善GNPs与基体之间的界面润湿性，从而促进了GNPs在复合材料中的均匀分散。结果，所制备的0.5 wt％Cu-NPs @ GNPs / Al-10Si复合材料的拉伸强度为251 MPa（比Al-10Si高45％），总伸长率为15％。增强效果主要归因于以下三个原因：首先，Cu-NPs涂层改善了GNP与Al基体之间的界面结合，从而促进了从基体到GNP的载荷转移。其次，纳米铝Cu-NPs与Al基体反应生成的₂ Cu在析出强化中起作用。第三，GNP细化了硅相并改善了复合材料的整体性能。