Abstract

Lighter and more powerful next generation vehicles and other rotary machinery demand bearings to operate in harsher conditions for higher efficiency, and the continuous development of advanced low-wear and friction materials is thus becoming even more important to meet these requirements. New aluminium composites reinforced with high performance lubricate phases such as graphene nanoplatelets (GNPs) are very promising and have been vigorously investigated. By maintaining a low coefficient of friction (COF) and offering great strength against wear due to their self-lubricating capability, the solid lubricant like GNPs protect the bearing surface from wear damage and prevent change in metallurgical properties during temperature fluctuations. This paper first studies the high-temperature tribological performance of aluminium matrix composites reinforced with GNP, consolidated via powder metallurgy, then elucidates their tribological mechanism. We report that the best tribological performance is achieved by the composite containing 2.0 wt% GNP, with an extraordinarily low COF of 0.09 and a specific wear rate of 3.5×10⁻² mm³·N⁻¹·m⁻¹, which represent 75% and 40% reduction respectively, against the plain aluminium consolidated under identical conditions. The in-track and out-of-track Raman analysis have confirmed the role of GNPs in creating a tribofilm on the counterpart surface which contributed to the excellent performance.

中文翻译：

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Al-GNP 复合材料在高温下的摩擦学性能

摘要

更轻、更强大的下一代车辆和其他旋转机械要求轴承在更恶劣的条件下运行以获得更高的效率，因此，不断开发先进的低磨损和摩擦材料对于满足这些要求变得更加重要。用高性能润滑相（例如石墨烯纳米片（GNP））增强的新型铝复合材料非常有前途，并且已得到大力研究。通过保持低摩擦系数 (COF) 并因其自润滑能力而提供强大的抗磨损强度，GNP 等固体润滑剂可保护轴承表面免受磨损损坏，并防止温度波动期间冶金性能发生变化。本文首先研究了粉末冶金固结 GNP 增强铝基复合材料的高温摩擦学性能，并阐明了其摩擦学机理。我们报告称，含有 2.0 wt% GNP 的复合材料实现了最佳摩擦学性能，其 COF 极低，为 0.09，比磨损率为 3.5×10 -2 ^mm 3 ^· N ^-1 ·m ^-1，相当于 75与相同条件下固结的纯铝相比，分别减少 % 和 40%。轨道内和轨道外拉曼分析证实了 GNP 在对应表面上形成摩擦膜的作用，这有助于实现优异的性能。