Graphene has been reported to be a promising nanofiller in fabricating advanced metal matrix composites. Graphene nanosheets (GNSs) have been incorporated into an aluminium matrix composite using mechanical milling and hot pressing in the current study. The SEM observation shows that aluminium particles are firstly flattened into flakes, and then fractured/ rewelded into equiaxed particles as the ball milling progresses. The crystalline size is decreased and the lattice strain is increased during the ball milling, which are also intensified by the added GNSs. The hardness of the composite is increased by 115.1% with the incorporation of 1.0 vol. % GNSs. The local stress induced by the hard GNSs accelerates the milling process. The X-Ray diffraction patterns show that the intensity ratio of (111) to (200) can reflect the preferred orientation of the particle mixture, and the evolution of I(111)/I(200) agrees well with the observed results using SEM. The increased hardness is mainly attributed to the refined microstructure and Orowan strengthening.

中文翻译：

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机械研磨制得的铝-石墨烯复合粉的微观结构和力学性能

据报道，石墨烯是制造先进金属基复合材料的有前途的纳米填料。在当前的研究中，已经通过机械研磨和热压将石墨烯纳米片（GNS）掺入到铝基复合材料中。SEM观察表明，随着球磨的进行，铝颗粒首先被压扁成薄片，然后破裂/重新焊接成等轴颗粒。在球磨过程中，晶体尺寸减小，晶格应变增加，这也因添加的GNS而增强。通过加入1.0vol。％的复合物，硬度提高了115.1％。％GNSs。硬GNS引起的局部应力加速了铣削过程。X射线衍射图谱表明，（111）与（200）的强度比可以反映颗粒混合物的择优取向，I（111）/ I（200）的演化与使用SEM观察到的结果非常吻合。硬度增加主要归因于精细的组织和Orowan强化。