Wear behavior of plasma and HVOF sprayed WC-12Co + 6% ETFE coatings on AA2024-T6 aluminum alloy

In this study, WC-12Co + 6% ethylene trifluoroethylene (ETFE) coatings were formed on the surface of an AA2024-T6 aluminum alloy using both plasma spray and high velocity oxygen fuel (HVOF) processes. The characterization of the coatings was made by microscopic examinations, thickness, porosity, contact angle and hardness measurements and X-ray diffraction (XRD) analysis. The coefficient of friction and wear resistance of coatings were obtained using a reciprocating wear tester by rubbing a 10 mm diameter Al2O3 ball on the coatings in dry and acid environments. It was observed that the WC-12Co + 6% ETFE coating sprayed using HVOF method exhibited higher hardness and contact angle, better tribological performance and higher amount of retained WC when compared to the plasma sprayed WC-12Co + 6% ETFE coating. The wear resistance of the HVOF sprayed WC-12Co + 6% ETFE coating tested in acid environment was almost one and a half times bigger than that of dry sliding condition, but the plasma sprayed WC-12Co + 6% ETFE coating tested in acid environment showed a lower wear resistance when compared to the result of the experiment performed on dry sliding condition.