Nanostructured tribolayer-dependent lubricity of graphene and modified graphene nanoflakes on sliding steel surfaces in humid air. (May 2020)

• Record Type: Journal Article
• Authors: Xu, Jianxun; Luo, Ting; Chen, Xinchun; Zhang, Chenhui; Luo, Jianbin
• Is Part Of: Tribology international. Volume 145(2020)
• Publication Date: 2020-05
• Subjects: Graphene and modified graphene -- Solution concentration -- Adding mode -- Tribolayer; Tribology -- Periodicals; 621.89
• DOI: 10.1016/j.triboint.2020.106203
• Languages: English
• ISSNs: 0301-679X

Abstract

Abstract: Graphene and modified graphene can provide exceptional lubrication when used as additives. Here, we applied several types of graphene on steel tribo-couples to perform friction tests. The results indicate that the solution concentration and processing method regarding the graphene-containing alcohol solution can significantly affect the lubrication performance. Graphene nanoflakes aggregated on the sliding interfaces and underwent structural transformation under high contact pressure after the alcohol completely evaporated. The wear track and wear scar were then effectively protected by the in situ as-formed tribolayer. In contrast, a tribolayer could not form when the tribo-couples slid in a solution environment, as the graphene adsorbed on the contact area could be removed away by the alcohol. Highlights: Various types of graphene lubricants are investigated regarding the interfacial friction evolution. The optimization concentration and processing method with respect to the graphene solution for lubrication are clarified. The growth mechanisms and structural characteristics of the graphene-induced tribolayers are analyzed at the atomic scale.