Grinding texture as a useful surface to reduce the friction of carbide-derived carbon coatings

A 150 μ m thick SiC coating was ground to form V-shaped and U-shaped grooves with a 10 μ m depth, which was followed by partial chlorination to convert the coating to a carbide-derived carbon (CDC) coating. The effect of the grooves in the CDC coating on its tribological properties was investigated. The grooves were removed by further grinding for comparison. It was found that the grooved CDC coating exhibited improved tribological properties in sliding against Si3N4 in both dry and moist conditions compared with the coating without grooves. The friction coefficient of the grooved CDC coating (0.05) against Si3N4 was lower than that of the ungrooved coating under moist conditions which can be accounted for by a hydrodynamic lubrication mechanism in the vicinity of the grooves. The grooves were also a useful surface texture to reduce the friction coefficient of the CDC coating in sliding against Si3N4 under dry conditions.