Micro/Nanotexture Design for Improving Tribological Properties of Cr/GLC Films in Seawater

ABSTRACT

Microdimples with different diameters and Cr/graphite-like carbon (GLC) films were fabricated on silicon by laser surface texturing and magnetron sputtering technology, respectively. The texturing effects on the microstructures and tribological performance in seawater were comparatively investigated. The results showed that both the friction coefficients and wear rates in seawater decreased with an increase in dimple diameter in the lower range and then increased with a further increase in diameter. The Cr/GLC film with an appropriate diameter of dimples (1.5 µm) is effective in enhancing the tribological properties due to entrapment of wear particles and seawater in the dimples. In addition, the roughness and graphitization contact area have obvious effects on the wear resistance. If the surface roughness is too high, the graphitization contact area will decrease, and the ratio of minimum aqueous film thickness to the surface roughness is so small that the load is almost totally borne by the boundary film.

KEYWORDS:

• Cr/GLC films
• diameter of dimple
• tribological properties
• seawater

Funding

This work was supported by the National Natural Science Foundation of China (Grant Nos. 51202263, 51161008, 51202261, and 51475449) and the National Basic Research Program of China (973 Program, Grant No. 2013CB632302).