Tribocorrosion Properties of NiCrAlY Coating in Different Corrosive Environments

Atmospheric plasma spraying (APS) was taken to fabricate the NiCrAlY coating. The corrosion-wear properties of NiCrAlY coating was measured respectively under deionized water, artificial seawater, NaOH solution and HCl solution. Experimental results presented that the as-sprayed NiCrAlY coating consisted of Ni(3)Al, nickel-based solid solution, NiAl and Y(2)O(3). In deionized water, the coating with the lowest corrosion current density (i(corr)) of 7.865 × 10(−8) A/cm(2) was hard to erode. Meanwhile, it presented a lower friction coefficient and the lowest wear rate. In HCl solution, NiCrAlY coating gave the highest corrosion current density (i(corr)) of 3.356 × 10(−6) A/cm(2) and a higher wear rate of 6.36 × 10(−6) mm(3)/Nm. Meanwhile, the emergence of Al(OH)(3) on the coating surface could reduce the direct contact between the counter ball and sample effectively, which was conducive to the lowest friction coefficient of 0.24.