Erosion–corrosion resistance of a β-Ta2O5 nanocrystalline coating in two-phase fluid impingement environments

ABSTRACTIn this study, a β-Ta2O5 coating was deposited onto a Ti–6Al–4V substrate using a double-cathode glow discharge plasma technique. The hardness and elastic modulus values of the β-Ta2O5 coating were almost 4 times and 1.8 times greater than that of the Ti–6Al–4V substrate, respectively. Potentiodynamic polarisation curves indicated that the current densities of the β-Ta2O5 coated sample are least one order of magnitude less than that observed for the uncoated substrate under a solid/liquid slurry flow. Electrochemical impedance spectroscopy results showed that the resistance values for the β-Ta2O5 coating are of the order of 106 Ω cm2, and at the same erosion time, the resistance value for the β-Ta2O5 coating is one order of magnitude greater than that of the Ti–6Al–4V.