Influence of Surface Roughness on the Lubrication Effect of Carbon Nanoparticle-Coated Steel Surfaces
- 53 Downloads
In the present study, a systematic evaluation of the influence of the surface roughness on the lubrication activity of multi-wall carbon nanotubes (MWCNT) and onion-like carbon (OLC) is performed. MWCNT and OLC are chosen as they both present an sp2-hybridization of carbon atoms, show a similar layered atomic structure, and exhibit the potential to roll on top of a surface. However, their morphology (size and aspect ratio) clearly differs, allowing for a methodical study of these differences on the lubrication effect on systematically varied surface roughness. Stainless steel platelets with different surface finishing were produced and coated by electrophoretic deposition with OLC or MWCNT. The frictional behavior is recorded using a ball-on-disk tribometer, and the resulting wear tracks are analyzed by scanning electron microscopy in order to reveal the acting tribological mechanisms. It is found that the lubrication mechanism of both types of particles is traced back to a mixture between a rolling motion on the surfaces and particle degradation, including the formation of nanocrystalline graphitic layers. This investigation further highlights that choosing the suitable surface finish for a tribological application is crucial for achieving beneficial tribological effects of carbon nanoparticle lubricated surfaces.
KeywordsSolid lubrication Carbon nanotubes Onion-like carbon Lubrication mechanisms Surface roughness
The present work is supported by funding from the Deutsche Forschungsgemeinschaft (DFG, project: MU 959/38-1 and SU 911/1-1). L. R., S.S., and F. M. wish to acknowledge the EFRE Funds of the European Commission for support of activities within the AMELab project. This work was supported by the CREATe-Network Project, Horizon 2020 of the European Commission (RISE Project No. 644013).
- 4.Li, Y., Li, B.X., Zou, W.J.: The relationship between nanocrystalline structure and frictional properties of nanodiamond/Ni composite coatings by brush plating. Appl. Mech. Mater. 80–81, 683–687 (2011). https://doi.org/10.4028/www.scientific.net/AMM.80-81.683 CrossRefGoogle Scholar
- 8.Gogotsi, Y., Presser, V.: Carbon Nanomaterials. CRC Press, Boca Raton (2014). ISBN 9781138076815Google Scholar
- 45.Gachot, C., Rosenkranz, A., Reinert, L., Ramos-Moore, E., Souza, N., Müser, M.H., Mücklich, F.: Dry friction between laser-patterned surfaces: role of alignment, structural wavelength and surface chemistry. Tribol. Lett. 9, 193–202 (2013). https://doi.org/10.1007/s11249-012-0057-y CrossRefGoogle Scholar
- 49.Greenwood, J., Williamson, J.: Contact of nominally flat surfaces. R. Soc. Publ. 295, 300–319 (1966)Google Scholar
- 57.Hwang, Y., Lee, C., Choi, Y., Cheong, S., Kim, D., Lee, K., Lee, J., Kim, S.H.: Effect of the size and morphology of particles dispersed in nano-oil on friction performance between rotating discs. J. Mech. Sci. Technol. 25, 2853–2857 (2011). https://doi.org/10.1007/s12206-011-0724-1 CrossRefGoogle Scholar
- 65.Reinert, L., Zeiger, M., Suarez, S., Presser, V., Mücklich, F.: Dispersion analysis of carbon nanotubes, carbon onions, and nanodiamonds for their application as reinforcement phase in nickel metal matrix composites. RSC Adv. 5, 95149–95159 (2015). https://doi.org/10.1039/C5RA14310A CrossRefGoogle Scholar