60% IACS Conductive Metal Coating on a Polymer Surface: Achievement of a Highly Efficient Additive Processing by Cold Spraying

This paper investigates a current challenge that enables the hybridization of different materials using a solid-state additive principle. We investigate the suitability of such a principle to easily and efficiently grow a metallic electrically conductive coating on a polymer substrate. The additive principle is obtained using the high-pressure cold spraying (CS) method whose literature does not include an achievement as suggested in this paper, that is, to obtain a good conductive copper coating onto polymer with a very high deposition efficiency by tuning the effect of the stand-off distance, transverse speed of the nozzle, and temperature of the carrier gas on the deposition efficiency (DE) in order to overcome delamination and erosion, and thus to improve the DE. A good coating formation up to 400 µm can be obtained, which implies that a standoff distance higher than 100 mm is needed, since both a high gas temperature (400–500 °C) and high gas pressure (30 bars) are required. A nozzle scanning velocity in the range of 200–300 mm/s gives the highest DE. The results reveal that the Cu coating on PEEK reaches a DE up to 91%, leading to an electrical conductivity up to 60% IACS (International Annealed Copper Standard). Thus, parametric analysis, along with the deposition optimization, promises to be feasible for the future in terms of DE improvement along with a good electrical conductivity in CS.