Al3+diffusion-directed assembly of GO-CNTs multi-layered composite coatings: Preparation and tribological performance

To resolve graphene coating’s typical problems in tribological applications, including poor interfacial bonding, agglomeration, and low wear resistance, a dimensionally composited coating based on graphene oxide (GO) and carbon nanotubes (CNTs) was successfully prepared by a feasible metal-ion diffusion-directed assembly method. Experiments showed that the Al3+diffusion-directed assembly method could significantly increase the coating interfacial binding strength, elasticity modulus, and hardness. In addition, the synergistic lubrication of GO and CNTs during friction enabled the Al3+-GO-CNTs5.0 coating to sustain a longer operation duration of 12,900 cycles. This study refers to inducing coordination with metal ions in various valence states and compositing carbon-based nanomaterials in different dimensions, which provides a feasible way to improve the lubricating coating’s mechanical and tribological performances.