Abstract Molecular dynamics simulations are performed to investigate the effects of graphene on the mechanical properties in multilayer Cu/graphene composites under uniaxial tension. It is found that both of zigzag and armchair graphene can improve the mechanical strength of multilayer Cu/graphene composites. The enhanced efficiency is concerned with chirality and interlayer thickness of graphene. The Cu/graphene interface has a great effect on the dislocation nucleation and propagation in the plastic deformation. Firstly, the interface can act as a resource of dislocation emission. This is due to the high stress concentrated on the interface caused by lattice mismatch and shear modulus mismatch between Cu and graphene, which can reduce the energy of nucleation. The interface stress of armchair graphene is more evident than the zigzag graphene. Secondly, the dislocations are confined by the impenetrable interface during the propagation process, which leads to intense interaction between dislocations and interface. Both the confinements and interactions are responsible for high stress required during the propagation process. A confined layer slip (CLS) model is established to predict the strength of multilayer composites in quantification. After the fracture of graphene, the dislocations penetrate through the interface of Cu and graphene and the composites would neck and fracture around the region.

中文翻译：

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Cu/石墨烯界面对多层Cu/石墨烯复合材料力学性能的影响

摘要 进行分子动力学模拟以研究石墨烯对单轴拉伸下多层铜/石墨烯复合材料力学性能的影响。结果表明，锯齿形石墨烯和扶手椅石墨烯均可提高多层铜/石墨烯复合材料的机械强度。提高的效率与石墨烯的手性和层间厚度有关。Cu/石墨烯界面对塑性变形中的位错形核和传播有很大影响。首先，界面可以作为位错发射的资源。这是由于Cu和石墨烯之间的晶格失配和剪切模量失配导致界面上集中的高应力，这会降低成核能量。扶手椅石墨烯的界面应力比锯齿形石墨烯更明显。其次，位错在传播过程中被不可穿透的界面所限制，导致位错与界面之间发生强烈的相互作用。限制和相互作用都是传播过程中所需的高应力的原因。建立了限制层滑移（CLS）模型以定量预测多层复合材料的强度。石墨烯断裂后，位错穿透铜和石墨烯的界面，复合材料在该区域周围发生颈缩和断裂。建立了限制层滑移（CLS）模型以定量预测多层复合材料的强度。石墨烯断裂后，位错穿透铜和石墨烯的界面，复合材料在该区域周围发生颈缩和断裂。建立了限制层滑移（CLS）模型以定量预测多层复合材料的强度。石墨烯断裂后，位错穿透铜和石墨烯的界面，复合材料在该区域周围发生颈缩和断裂。