The present study investigates the mechanical and tribological properties of an epoxy matrix filled with different graphitic particles deposited on an aluminum substrate by the electrostatic spray technique. Three different particles added to the epoxy matrix were the received graphite, the crushed graphite obtained by crushing the natural flake graphite particles using a ball mill, and graphite oxide obtained by oxidation treatment. Nanoindentation tests were conducted on the different coatings in order to evaluate the surface hardness and the contact elastic modulus. The effect of the oxidation treatment and the loading content on the tribological behavior of the above composites were also evaluated under dry-friction conditions. As expected, the smaller the particle size, the greater the reduction in the dynamic friction. The experimental findings showed that adding 5 wt % of crushed graphite (10 µm) provided a similar dynamic friction as the addition of 10 wt % of received graphite (20 µm). The epoxy filled with received graphite showed a lower wear rate than that filled with graphite oxide and crushed graphite. Moreover, both hardness and elastic modulus increased in the case of the epoxy filled with graphite oxide and crushed graphite.

中文翻译：

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环氧/石墨复合涂层的摩擦学和机械特性：颗粒大小和氧化的影响

本研究调查了通过静电喷涂技术沉积在铝基板上的填充有不同石墨颗粒的环氧树脂基体的机械和摩擦学性能。添加到环氧树脂基体中的三种不同颗粒是接收的石墨、通过使用球磨机粉碎天然鳞片石墨颗粒获得的粉碎石墨和通过氧化处理获得的氧化石墨。为了评估表面硬度和接触弹性模量，对不同涂层进行了纳米压痕测试。还在干摩擦条件下评估了氧化处理和负载含量对上述复合材料摩擦学行为的影响。正如预期的那样，粒径越小，动摩擦的降低越大。实验结果表明，添加 5 wt% 的碎石墨 (10 µm) 提供了与添加 10 wt% 的接收石墨 (20 µm) 相似的动摩擦。填充石墨的环氧树脂的磨损率低于填充氧化石墨和碎石墨的环氧树脂。此外，在填充有氧化石墨和粉碎石墨的环氧树脂的情况下，硬度和弹性模量均增加。