Frictional Properties of Element- and Compound-Doped Diamond-Like Carbon Films under Boundary Lubrication with Synthetic Base Oil

Abstract:

The frictional properties of diamond-like carbon (DLC) films under boundary lubrication with a synthetic base oil were investigated. The specimens tested were a-C:H, Cr-a-C:H, Ti-a-C:H, W-a-C:H, WC-a-C:H, Mo-a-C:H, MoS2-a-C:H, and Sn-a-C:H films. The tribological properties of DLC/steel contacts were evaluated using a reciprocating-type cylinder-on-disk tribotester. The DLC films exhibited different frictional properties depending on the type of doping elements and compounds used. Notably, the Sn-a-C film gave the lowest friction. The friction tests and static contact angle analyses revealed that the average friction coefficient decreased with a decrease in the static contact angle of the worn DLC film surface, demonstrating that the DLC films with relatively high surface wettabilities exhibited relatively low friction properties. Therefore, surface wettability plays an important role in determining the frictional properties of DLC films under boundary lubrication with synthetic base oil..

• Periodical: Defect and Diffusion Forum (Volume 414)
• Pages: 13-19
• DOI: https://doi.org/10.4028/p-80r92b
• Online since: February 2022
• Authors: Hikaru Okubo*, Shinya Sasaki
• Keywords: Boundary Lubrication, Diamond-Like Carbon, Polyalphaolefin

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