ABSTRACT Graphene and its derivatives, due to their extraordinary mechanical, thermal, and tribological properties, are extensively used to fabricate bulk graphene-based nanocomposites. On the other hand, magnesium alloys are lightweight and manifest excellent mechanical properties. In the present study, the hardness and compressive responses of Mg–3 wt%Al/xRGO (x = 0.1 wt% and 0.3 wt.%) nanocomposites at ambient temperature were investigated. Further, the coefficient of thermal expansion of Mg–3 wt%Al/xRGO (x = 0.1 wt% and 0.3 wt.%) nanocomposites at elevated temperatures were estimated and compared with those of pure Mg and Mg–3 wt%Al alloy. Reduced graphene oxide (RGO) synthesized through the improved Hummer’s Method followed by the thermal reduction method was used as the reinforcement material. The bulk samples of pure Mg, Mg–3%Al alloy, and nanocomposites were synthesized by blending of Mg, Al and RGO powder followed by cold compaction, microwave sintering and hot extrusion. Nanocomposite samples displayed significant changes in microstructures and substantial improvements in both Vickers hardness and ultimate compressive strength. The lower thermal expansion coefficients of Mg–3%Al/xRGO (x = 0.1 wt% and 0.3 wt.%) nanocomposites demonstrated better thermal and dimensional stability with respect to temperature. The obtained results would be conducive to design lightweight structural materials.

中文翻译：

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RGO增强Mg-3%Al合金纳米复合材料的合成与分析

摘要石墨烯及其衍生物由于其非凡的机械、热和摩擦学特性，被广泛用于制造块状石墨烯基纳米复合材料。另一方面，镁合金重量轻并表现出优异的机械性能。在本研究中，研究了 Mg–3 wt% Al/xRGO（x = 0.1 wt% 和 0.3 wt.%）纳米复合材料在环境温度下的硬度和压缩响应。此外，还估算了 Mg-3 wt%Al/xRGO（x = 0.1 wt% 和 0.3 wt.%）纳米复合材料在高温下的热膨胀系数，并与纯 Mg 和 Mg-3 wt%Al 合金的热膨胀系数进行了比较。通过改进的悍马法和热还原法合成的还原氧化石墨烯 (RGO) 用作增强材料。纯 Mg、Mg-3%Al 合金的大块样品，和纳米复合材料是通过混合镁、铝和 RGO 粉末，然后冷压、微波烧结和热挤压来合成的。纳米复合材料样品的微观结构发生了显着变化，维氏硬度和极限抗压强度都有显着提高。Mg–3%Al/xRGO（x = 0.1 wt% 和 0.3 wt.%）纳米复合材料的较低热膨胀系数表现出更好的热稳定性和尺寸稳定性。所得结果将有利于设计轻量化结构材料。纳米复合材料样品的微观结构发生了显着变化，维氏硬度和极限抗压强度都有显着提高。Mg–3%Al/xRGO（x = 0.1 wt% 和 0.3 wt.%）纳米复合材料的较低热膨胀系数表现出更好的热稳定性和尺寸稳定性。所得结果将有利于设计轻量化结构材料。纳米复合材料样品的微观结构发生了显着变化，维氏硬度和极限抗压强度都有显着提高。Mg–3%Al/xRGO（x = 0.1 wt% 和 0.3 wt.%）纳米复合材料的较低热膨胀系数表现出更好的热稳定性和尺寸稳定性。所得结果将有利于设计轻量化结构材料。