Tribological Performance of a Ni-Based Composite Coating in Artificial Seawater

Authors :: Zhao Siyong
Yunchuan Kang
Li Bo
Yimin Gao
Hongjian Guo
Cong Li
Source :: Coatings, Volume 9, Issue 11, Coatings, Vol 9, Iss 11, p 747 (2019)
Publication Year :: 2019
Publisher :: MDPI AG, 2019.
Abstract: NiCrAlY and NiCrAlY-Mo coatings were fabricated by atmospheric plasma spraying (APS). The corrosion-wear performance of the coatings was investigated in artificial seawater and the synergistic mechanism between wear and corrosion were evaluated in detail. Results showed that the diffraction peaks of Ni3Al shifted to the right and the microhardness of the coating was improved from 329.8 HV to 342.5 HV with adding the Mo element. Meanwhile, the NiCrAlY-Mo coating had a lower friction coefficient, with a wear rate of 0.26 and 3.69 &times<br />10&minus<br />6 mm3/Nm, compared to the NiCrAlY coating with a wear rate of 0.37 and 4.67 &times<br />6 mm3/Nm. The NiCrAlY coating had severe corrosion and the corrosion mainly occurred in grain boundary. Adding the Mo element, the Mo element was distributed in the grain boundary and the coating had a lower corrosion rate and visibly slighter corrosion. The NiCrAlY-Mo coating had excellent corrosion-wear properties in artificial seawater.