Molecular dynamics studies on mechanical properties and deformation mechanism of graphene/aluminum composites
Molecular dynamics studies on mechanical properties and deformation mechanism of graphene/aluminum composites
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DOI：
10.1016/j.commatsci.2022.111487
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发表时间：
2022-08
影响因子：
3.3
通讯作者：
Mengying Li;X. Lei
中科院分区：
文献类型：
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作者：
Mengying Li;X. Lei
本研究采用分子动力学(MD)方法研究了石墨烯/铝(Gr/Al)复合材料在单轴拉伸和压缩下的力学性能。采用6种不同的模拟模型研究了石墨烯的加入是否显著提高了Gr/Al复合材料的硬度和强度。此外，结果还表明，石墨烯的存在可以有效地阻止位错在界面上的传播，从而提高了复合材料的力学性能。通过比较变形行为、压应力和位错对复合材料变形机制的影响，研究了复合材料的变形机制。进一步研究了Al基体在压缩过程中的位错运动。结果表明，Al基体中存在阶梯状位错和Hirth位错，石墨烯层发生鼓包和扭结变形。此外，测量了石墨烯压缩表面的平均曲率和高斯曲率，并用几何方法考虑了石墨烯在复合材料中的变形特征。我们应用了一种新的方法来计算表面曲率和材料的机械变形。
In this study, the mechanical properties of a graphene/aluminum (Gr/Al) composite under uniaxial tension and compression were investigated using molecular dynamics (MD) simulations. Six different simulation models were used to investigate whether the addition of graphene significantly improved the stiffness and strength of Gr/Al composites. Moreover, the results show that the existence of a graphene layer can effectively prevent the propagation of dislocations at the interface, thus improving the mechanical properties of the composites. The deformation mechanism of the composites was studied by comparing the effects of the deformation behavior, compressive stress, and dislocation. The dislocation movement of the Al matrix during compression was further investigated. It was determined that stair-rod and Hirth dislocations occurred in the Al matrix, and the graphene layers exhibited bulging and kink deformation. Furthermore, the mean curvature and Gaussian curvature of the compressed graphene surface were measured, and the deformation characteristics of graphene in the composites were considered using the geometric method. We applied a new method to calculate the surface curvature and mechanical material deformation.