Study of protective diamond-like carbon films on GCr15 bearing steel

Abstract

Hydrogenated diamond-like carbon (H-DLC) were deposited on GCr15 bearing steel by double cathodes pulse glow discharge (DCPGD) plasma vapour deposition at different gas volume ratios. The surface morphology, composition, microstructure, hardness and friction properties of the H-DLC films were observed. It was found that the sp 3 bond content and I(D)/I(G) ratio of DLC films were between 58 and 61% and in the range of 0?68-0?88, respectively. When H 2 : Ar : C 2 H 2 gas volume ratio ranges from 4 : 1 : 1 to 8 : 1 : 1, the I(D)/I(G) ratio decreases with an increase in the sp 3 bond content, the friction coefficient (about 0?1) and wear rate (between 4?5610 28 and 8?4610 28 mm 3 N 21 m 21 ) of DLC films were very low. In this study, when H 2 : Ar : C 2 H 2 gas volume ratio is 6 : 1 : 1, the thickness of the film is 8?13 mm deposited for is 4 h, the hardness reaches a maximum value (22?5 GPa), the friction coefficient and wear rate reduce to a minimum value, 0?094 and 4?5610 28 mm 3 N 21 m 21 , respectively.

Lubrication of aluminium versus diamond-like carbon contacts with hydrophobin proteins

“…15 Diamond-like carbon (DLC) coatings are known for their high hardness, low friction, high wear resistance, as well as for their biocompatibility, which makes them suitable for biomedical applications. 16 Normally, DLC coatings can be divided into hydrogen-containing (a-C: H) and hydrogen-free (a-C) coatings. The a-C:H coatings display low friction and wear under dry conditions, whereas the friction coefficients increase to more than 0.1 in water or oxygen-containing environments.…”