Enhancement of friction performance of nanocomposite fluorinated graphene and molybdenum disulfide coating by microdimple array

Two-dimensional (2D) materials, including graphene-family materials and molybdenum disulfide (MoS₂), have been used as solid lubricants because of their low interlayer shear strength. In this study, a fluorinated graphene (FG)–MoS₂ nanocomposite coating was deposited on a stainless-steel substrate with a laser surface textured dimple array. The FG–MoS₂ nanocomposite coating deposited on a textured surface led to the reduction in the coefficient of friction to 0.036, and it significantly reduced wear and extended the lifetime compared with those obtained using the MoS₂ coating. The excellent tribological performance is attributed to the synergetic effect between FG and MoS₂ nanoflakes and the function of texture, where the MoS₂ nanoflakes dominate the lubrication performance because of interlayer shearing, and the FG nanoflakes suppress the influence of external humidity on MoS₂ nanoflakes because of their hydrophobic nature. Meanwhile, the textured surface can promote the formation of a tribofilm through changing the stress distribution at the sliding interface and act as a reservoir for nanoflakes, leading to a much lower friction and longer lifetime. This has implications for the development of functional surfaces with excellent lubrication and wear-resistance performances with 2D materials.