An assessment of tribological performance on NiCoCrAlYTa coating under corrosive environments

The tribological performance of NiCoCrAlYTa coating under 0.1 M HCl and NaOH solutions was evaluated in comparison with those in deionized water and under dry sliding. Results indicate that the coating exhibits better tribological behavior under HCl and NaOH solutions than that in deionized water and under dry friction which is opposite to the variation of the mechanical properties as a result of the generation of the corrosion products between the friction pairs. The corrosion products, such as Ta2O5, Al2O3 and Cr2O3, improved the bearing ability of the coatings, thereby decreasing the wear rates. What's more, due to the formation of Al(OH)3 on the smooth surface, the coating sliding in HCl solution got the lowest friction coefficient and wear rate.