Metallization of polyether ether ketone (PEEK) by copper coating via cold spray

The metallization of polymer-based materials via cold spray has been attractive to improve its thermal and electrical properties, while the direct deposition of thick Cu coating was rarely reported. In this work, relatively low process parameters were used to metallize PEEK substrate via cold spray to enhance the electrical properties of PEEK. The coating microstructure and properties such as microhardness and electrical conductivity were investigated at different propelling gas pressures. A thick and dense Cu coating was produced on PEEK substrate with only three passes of deposition. Based on Raman spectra, the polymer structures of PEEK substrate were well retained after high-velocity impact in cold spray. Meanwhile, the electrical conductivity and microhardness of the cold sprayed coating on PEEK increase at a higher propelling gas pressure. At last, the splat morphology of single Cu particle deposition on PEEK accompanying the finite element analysis were used to discuss the deposition mechanism of metallic particle on polymer surface. More prominent material jet was formed at the substrate at a higher propelling gas pressure as the adiabatic shear instability is more evident at higher particle impact velocity, which facilitates the deposition of metallic coating on PEEK.