Title: Study on the deposition and tribological properties of diamond/DLC composite coating on WC-Co substrate

Authors: Bin Shen; Liang Wang; Sulin Chen; Fanghong Sun

Addresses: School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China ' School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China ' School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China ' School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China

Abstract: Two types of diamond/DLC composite films, namely MCD/DLC and NCD/DLC, are fabricated on the WC-Co substrate by depositing a layer of DLC film on the surface of conventional MCD and NCD film. Characterisations on their surface morphology suggest that the diamond/DLC composite films exhibit a rather similar surface topography, but much lower surface roughness, comparing with the single-layered MCD or NCD film. The atomic-bonding state on their surface is largely determined by the top-layered DLC film, which is mainly composed of amorphous carbon phase. The results of friction tests indicate that the self-lubricating effect of top-layered DLC film significantly suppresses the initial friction peak and shortens the run-in period. With silicon nitride as the counterpart material, the average friction coefficients of MCD/DLC and NCD/DLC composite films during stable sliding period are respectively 0.07 and 0.10 in dry sliding, and 0.03 and 0.07 under water-lubricating condition.

Keywords: diamond-DLC composite films; diamond like carbon; HFCVD; vacuum arc discharge; tribological properties; composite coatings; WC-Co substrates; tungsten carbide; cobalt; surface morphology; surface roughness; surface quality; friction coefficient; dry sliding; water lubrication.

DOI: 10.1504/IJAT.2013.053169

International Journal of Abrasive Technology, 2013 Vol.6 No.1, pp.58 - 69

Received: 27 Nov 2012
Accepted: 10 Jan 2013
Published online: 05 Jul 2014 *

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