Abstract Electroplated composite Au/SiO2 coatings on a nickel substrate have been produced by dispersing an emulsion of silica nanoparticles (20 nm in diameter) in an industrial hard-gold bath. The tribological behaviour of the Au/SiO2 coatings with different SiO2 content were investigated under sliding conditions against an alumina counterpart at different loads and sliding velocities. The tribological induced transformation of the coated surfaces were analysed using 3D-profilometry, scanning electron microscopy (SEM), focused-ion beam (FIB) cross sectioning and Auger electron spectroscopy (AES). The composite coatings provide higher hardness and ten-fold longer lubricating lifetime compared to the original hard gold coating. Hardness was identified as a key factor reducing the adhesive component of friction and increasing the resistance of gold against smearing. These effects allow to postpone the exposure of the nickel substrate and thus the loss of the self-lubricating character of the coating.

中文翻译：

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二氧化硅纳米粒子增强电镀金涂层的摩擦学行为

摘要 通过将二氧化硅纳米粒子（直径为 20 nm）的乳液分散在工业硬金浴中，在镍基材上电镀复合 Au/SiO2 涂层。研究了不同 SiO2 含量的 Au/SiO2 涂层在滑动条件下与不同载荷和滑动速度下的氧化铝对应物的摩擦学行为。使用 3D 轮廓测量法、扫描电子显微镜 (SEM)、聚焦离子束 (FIB) 横截面和俄歇电子能谱 (AES) 分析了涂层表面的摩擦诱导转变。与原始硬金涂层相比，复合涂层具有更高的硬度和十倍的润滑寿命。硬度被认为是减少摩擦的粘合成分和增加金对涂抹的抵抗力的关键因素。这些效果允许延迟镍基材的暴露，从而延迟涂层的自润滑特性。