Mechano-Chemical Surface Modification with Cu2S: Inducing Superior Lubricity


Advances toward low friction surfaces are in growing demand from many economic sectors for energy efficiency and environmental safety. However, the traditional approach of multi-grade oil formulation is limited by its inability to induce pollution-free generation of uniform oil-retaining films needed to improve surface lubricity. Here, a direct route to the formation of a surface layer of superior lubricity is presented as an alternative to the use of oil additives for friction reduction. The deformation-induced generation of a surface film consisting of low-shear-strength oil-retaining compounds is obtained via supplying chemically beneficial elements during a widely used surface finishing mechanical treatment. An ultra-low friction coefficient of about 0.01 is obtained with base oil lubrication after tailoring the surface chemistry by shot peening using a mixture of Cu2S and Al2O3; this result opens new horizons for surface engineering.

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We acknowledge the support of the Grand Technion Energy Program, the Carl E. Schustak Energy Research and Development Fund, and the New York Metropolitan Research Fund to M.V. This work was performed in part at the Georgia Tech Institute for Electronics and Nanotechnology, a member of the National Nanotechnology Coordinated Infrastructure, which is supported by the National Science Foundation (Grant ECCS-1542174).

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Correspondence to Michael Varenberg.

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Varenberg, M., Ryk, G., Yakhnis, A. et al. Mechano-Chemical Surface Modification with Cu2S: Inducing Superior Lubricity. Tribol Lett 64, 28 (2016).

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  • Plastic deformation
  • Surface activation
  • Solid-state chemistry
  • Surface films
  • Friction