Microstructure and anti- wear and corrosion performances of novel UHMWPE/graphene-nanosheet composite coatings deposited by flame spraying

Ultra-high molecular weight polyethylene (UHMWPE)/graphene-nanosheet (GN, multiple layers of graphene sheets with the thickness of ~5-10nm) coatings have been deposited by flame spraying. The structure of UHMWPE remained almost intact after the spray processing and addition of GNs resulted in a slightly decreased crystallinity and improved thermal stability of UHMWPE. In addition, the coating containing 1.0wt.% GNs exhibited a reduction of ~20% in wear rate and 25% in friction coefficient (0.18 versus 0.24). Significantly enhanced anti-corrosion performances of the UHMWPE-GN coatings were suggested by increased corrosion potential, corrosion current density, and impedance modulus value of the UHMWPE-GN coatings. The very well retained GNs are located mainly at the interfaces between UHMWPE splats and act as bridges connecting the splats, which mainly accounts for the enhanced properties of the composite coatings. The novel UHMWPE-graphene composite coatings show great potential for protecting engineering components for applications against corrosion.