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The tribological performances of Cr/GLC film coupling with Si 3 N 4 , SiC, WC, Al 2 O 3 and ZrO 2 were comparatively studied in seawater. Results indicated that the Cr/GLC film coupling with different ceramic counterparts exhibited different friction behaviors, which was closely related to the mechanical performances of mating ceramics. Meanwhile, the tribo-chemical products between the Cr/GLC film and ceramics also played an important role in improving the tribological performances. Friction coefficient and wear rate of the Cr/GLC film sliding against Si 3 N 4 were lower than others, which indicated that the Cr/GLC film coupled to Si 3 N 4 ceramic exhibited optimum tribological performance in seawater. [ABSTRACT FROM AUTHOR]

In this paper, the patterns of micro-dimples with different area densities and the Cr/GLC films were fabricated by laser surface texturing and magnetron sputtering technology, respectively. The morphologies and surface chemical states of the Cr/GLC films were characterized by AFM, SEM, and XPS. The effects of dimple area density on the tribological behavior of Cr/GLC films under seawater condition were investigated by UMT-3 tribometer in a ball-on-plate reciprocating mode. The experimental results showed that the Cr/GLC film was mainly composed by Cr–C and C–C bonds. Both the friction coefficients and wear rates of the Cr/GLC films in seawater decreased with the increase of dimple area densities in the lower range, whereas, they were constant when the dimple area densities further increased. The Cr/GLC films with proper dimple area density (G3 film) were effective in enhancing the tribological properties because of the entrapment of graphitized particles and seawater in the dimples. The graphitized particles can reduce the strong adhesive interaction between contact surfaces, resulting in the low frictional shear resistance during sliding process. Furthermore, Ca 2 + and Mg 2 + in seawater will be deposited on the counterface in the form of Mg(OH) 2 and CaCO 3 , which with sludge-like matters have some lubricating effects. At the same time, the Cr/GLC films with low dimple area densities exhibited low surface roughness, which could decrease the resistance in sliding process. [ABSTRACT FROM AUTHOR]

CrCN coatings were deposited using the multi-arc ion plating with different C 2 H 2 flow rates. Microstructures, mechanical and tribological performances were systematically investigated. The results showed that the peak intensity correlated to Cr 7 C 3 crystal phase became stronger when the flow rates increased from 0 to 15 sccm, whereas, it was decreased when the C 2 H 2 flow rate increased to 30 sccm. The hardness increased to 32.5 GPa due to formation of Cr 7 C 3 phase and amorphous CN x at 10 sccm. CrCN coatings deposited at 10–15 sccm exhibited a better comprehensive performance, indicating their potential application as a protective coating for tribo-components in seawater. [ABSTRACT FROM AUTHOR]

The two-layer and multi-layer Cr/Cr x N coatings were fabricated on 316 L stainless steel (316 L SS) substrates by the arc ion plating technique. The two-layer Cr/Cr x N coating was a typical CrN coating with an adhesive Cr layer. And the multi-layer Cr/Cr x N coating design was in two dimensions. In the first dimension, the multi-layer Cr/Cr x N coating consisted of alternative Cr/CrN layers with the thickness ratio of 1:5; in the second dimension, the alternative Cr 2 N layers with the thickness of 10 nm were inserted in CrN layers. This design was expected to increase transverse interfaces in a smaller scale. The microstructures, mechanical, corrosion and tribocorrosion performances of both Cr/Cr x N coatings were systematically investigated. The results showed that the special multi-layer design of Cr/Cr x N coatings improved mechanical, anti-corrosion and anti -tribocorrosion performances. Compared with the two-layer Cr/Cr x N coating, the reduced tribocorrosion damage of the muti-layer Cr/Cr x N coating was closely related to the inhibited synergistic effect between electrochemical corrosion and mechanical wear. In conclusion, the multi-layer Cr/Cr x N coating was more suitable to work as the surface protective coating than the two-layer Cr/Cr x N coating in seawater. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]