Abstract The strong interface is an essential requirement to ensure the effective load transfer of graphene/Cu composites. Here we attempted to improve the interface adhesion and mechanical properties of reduced graphene oxide (RGO)/CuCr composites by matrix-alloying with ∼0.2 at.% Cr. It was found that a trace amount of Cr7C3 layers/nanoparticles was in-situ formed at the RGO-CuCr interface, which contributed to the dramatically improved interfacial bonding of the composites. The 2.5 vol% RGO/CuCr composite exhibited a tensile strength of 352 MPa, 82% and 19% higher than that of unreinforced CuCr and 2.5 vol% RGO/Cu composite without Cr alloying, respectively. The enhanced strength of RGO/CuCr composite was ascribed to the dual role of Cr7C3 layers/nanoparticles that not only enhanced the load transfer efficiency, but also promoted the dislocation strengthening ability of RGO itself. Furthermore, we proposed the possible Cr7C3 formation/evolution mechanism that involved the four steps of amorphous carbon formation, Cr7C3 nucleation in amorphous carbon, Cr7C3 growth and Cr7C3 coalescence. The formation of medium sized Cr7C3 layers/nanoparticles at 1053 K resulted in the highest strength of RGO/CuCr composite with a satisfactory strength-ductility combination. This study provides new insights into the interface structure, strengthening mechanism and carbide formation/evolution mechanism of graphene/CuX composites.

中文翻译：

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石墨烯/CuCr复合材料的界面结构和强化行为

摘要 强界面是保证石墨烯/铜复合材料有效负载转移的必要条件。在这里，我们尝试通过基体合金化与 ~0.2 at.% Cr 来改善还原氧化石墨烯 (RGO)/CuCr 复合材料的界面粘附力和机械性能。结果表明，在 RGO-CuCr 界面处原位形成了微量的 Cr7C3 层/纳米颗粒，这有助于显着改善复合材料的界面结合。2.5 vol% RGO/CuCr 复合材料的拉伸强度为 352 MPa，分别比未增强的 CuCr 和 2.5 vol% RGO/Cu 复合材料高 82% 和 19%，没有 Cr 合金化。RGO/CuCr 复合材料的强度增强归因于 Cr7C3 层/纳米颗粒的双重作用，不仅提高了负载转移效率，同时也提升了RGO本身的位错强化能力。此外，我们提出了可能的 Cr7C3 形成/演化机制，涉及无定形碳形成、无定形碳中 Cr7C3 成核、Cr7C3 生长和 Cr7C3 聚结四个步骤。在 1053 K 下形成中等大小的 Cr7C3 层/纳米颗粒导致 RGO/CuCr 复合材料的强度最高，并具有令人满意的强度-延展性组合。该研究为石墨烯/CuX复合材料的界面结构、强化机制和碳化物形成/演化机制提供了新的见解。在 1053 K 下形成中等大小的 Cr7C3 层/纳米颗粒导致 RGO/CuCr 复合材料的强度最高，并具有令人满意的强度-延展性组合。该研究为石墨烯/CuX复合材料的界面结构、强化机制和碳化物形成/演化机制提供了新的见解。在 1053 K 下形成中等大小的 Cr7C3 层/纳米颗粒导致 RGO/CuCr 复合材料的强度最高，并具有令人满意的强度-延展性组合。该研究为石墨烯/CuX复合材料的界面结构、强化机制和碳化物形成/演化机制提供了新的见解。