Doping carbon to improve the tribological performance of CrN coatings in seawater

CrN and CrCN coatings were deposited by the cathodic arc ion plating technique. Microstructures, mechanical properties and tribological performances of the CrN and CrCN coatings in ambient air, distilled water and seawater were comparatively investigated. Results showed that the amorphous carbon and carbides were formed in the CrCN coating. The CrCN exhibited lower friction and wear than the CrN in these three environments. The lower friction performance of the CrCN coating was closely related to the self-lubricating amorphous carbon phase. While, the better anti-wear performance in seawater could be attributed to the superior mechanical properties, the better anti-corrosion performance and the lower friction shear.