Friction

, Volume 2, Issue 2, pp 193–208 | Cite as

Surface passivation and boundary lubrication of self-mated tetrahedral amorphous carbon asperities under extreme tribological conditions

  • Pedro A. Romero
  • Lars Pastewka
  • Julian Von Lautz
  • Michael Moseler
Open Access
Research Article

Abstract

Tetrahedral amorphous carbon coatings have the potential to significantly reduce friction and wear between sliding components. Here, we provide atomistic insights into the evolution of the sliding interface between naked and hydrogen-passivated ta-C sliding partners under dry and lubricated conditions. Using reactive classical atomistic simulations we show that sliding induces a sp3 to sp2 rehybridization and that the shear resistance is reduced by hydrogen-passivation and hexadecane-lubrication—despite our finding that nanoscale hexadecane layers are not always able to separate and protect ta-C counter surfaces during sliding. As asperities deform, carbon atoms within the hexadecane lubricant bind to the ta-C sliding partners resulting in degradation of the hexadecane molecules and in increased material intermixing at the sliding interface. Hydrogen atoms from the passivation layer and from the hexadecane chains continue to be mixed within a sp2 rich sliding interface eventually generating a tribo-layer that resembles an a-C:H type of material. Upon separation of the sliding partners, the tribo-couple splits within the newly formed sp2 rich a-C:H mixed layer with significant material transfer across the sliding partners. This leaves behind a-C:H coated ta-C surfaces with dangling C bonds, linear C chains and hydrocarbon fragments.

Keywords

Atomic-scale simulations DLC lubrication hexadecane passivation sliding mixed layer wear 

References

  1. [1]
    Robertson J. Diamond-like amorphous carbon. Mater Sci Eng R37: 129–281 (2002)CrossRefGoogle Scholar
  2. [2]
    Erdemir A, Donnet C. Tribology of diamond-like carbon films: Recent progress and future prospects. J Phys D39: R311–R327 (2006)CrossRefGoogle Scholar
  3. [3]
    Donnet C, Erdemir A. Tribology of Diamond-Like Carbon Films: Fundamentals and Applications. Springer US, 2008.CrossRefGoogle Scholar
  4. [4]
    Cho S, Chasiotis I, Friedmann T A, Sullivan J P. Young’s modulus, Poisson’s ratio and failure properties of tetrahedral amorphous diamond-like carbon for MEMS devices. J Micromech Microeng15: 728–735 (2005)CrossRefGoogle Scholar
  5. [5]
    Konicek A R, Grierson D S, Gilbert P U P A, Sawyer W G, Sumant A V, Carpick R W. Origin of ultra-low friction and wear in ultrananocrystalline diamond. Phys Rev Lett100: 235502 (2008)CrossRefGoogle Scholar
  6. [6]
    Konicek A R, Grierson D S, Sumant A V, Friedmann T A, Sullivan J P, Gilbert P U P A, Sawyer W G, Carpick R W. Influence of surface passivation on the friction and wear behavior of ultrananocrystalline diamond and tetrahedral amorphous carbon thin films. Phys Rev B85: 155448 (2012)CrossRefGoogle Scholar
  7. [7]
    Joly-Pottuz L, Matta C, de Barros Bouchet M I, Vacher B, Martin J M, Sagawa T. Superlow friction of taC lubricated by glycerol: An electron energy loss spectroscopy study. J Appl Phys102: 064912 (2007)CrossRefGoogle Scholar
  8. [8]
    Kunze T, Posselt M, Gemming S, Seifert G, Konicek A, Carpick R, Pastewka L, Moseler M. Wear, plasticity, and rehybridization in tetrahedral amorphous carbon. Tribol Lett53: 119–126 (2014)CrossRefGoogle Scholar
  9. [9]
    Matta C, De Barros Bouchet M I, Le-Mogne T, Vachet B, Martin J M, Sagawa T. Tribochemistry of tetrahedral hydrogen-free amorphous carbon coatings in the presence of OH-containing lubricants. Lubr Sci20: 137–149 (2008)CrossRefGoogle Scholar
  10. [10]
    Harrison J A, Brenner D W. Simulated tribochemistry-An atomic-scale view of the wear of diamond. J Am Chem Soc116: 10399–10402 (1994)CrossRefGoogle Scholar
  11. [11]
    Gao G T, Mikulski P T, Harrison J A. Molecular-scale tribology of amorphous carbon coatings: Effects of film thickness, adhesion, and long-range interactions. J Am Chem Soc124: 7202–7209 (2002)CrossRefGoogle Scholar
  12. [12]
    Pastewka L, Moser S, Moseler M. Atomistic insights into the running-in, lubrication, and failure of hydrogenated diamond-like carbon coatings. Tribol Lett39: 49–61 (2010)CrossRefGoogle Scholar
  13. [13]
    Schall J D, Gao G, Harrison J A. Effects of adhesion and transfer film formation on the tribology of self-mated DLC contacts. J Phys Chem C114: 5321–5330 (2010)CrossRefGoogle Scholar
  14. [14]
    Hyun S, Pei L, Molinari J-F, Robbins M O. Finite-element analysis of contact between elastic self-affine surfaces. Phys Rev E70: 026117 (2004)CrossRefGoogle Scholar
  15. [15]
    Persson B N J, Albohr O, Tartaglino U, Volokitin A I, Tosatti E. On the nature of surface roughness with application to contact mechanics, sealing, rubber friction and adhesion. J Phys: Condens Matter17: R1–R26 (2005)Google Scholar
  16. [16]
    Carbone G, Bottiglione F. Asperity contact theories: Do they predict linearity between contact area and load? J Mech Phys Solids56: 2555–2572 (2008).CrossRefGoogle Scholar
  17. [17]
    Pastewka L, Robbins M O. Contact between rough surfaces and a criterion for macroscopic adhesion. Proc Natl Acad Sci USA111: 3298–3303 (2014)CrossRefGoogle Scholar
  18. [18]
    Moras G, Pastewka L, Walter M, Schnagl J, Gumbsch P, Moseler M. Progressive shortening of sp-hybridized carbon chains through oxygen-induced cleavage. J Phys Chem C115: 24653–24661 (2011)CrossRefGoogle Scholar
  19. [19]
    Moras G, Pastewka L, Gumbsch P, Moseler M. Formation and oxidation of linear carbon chains and their role in the wear of carbon materials. Tribol Lett44: 355–365 (2011)CrossRefGoogle Scholar
  20. [20]
    M’ndange-Pfupfu A, Eryilmaz O, Erdemir A, Marks L. Quantification of sliding-induced phase transformation in N3FC diamond-like carbon films. Diam Relat Mater20: 1143–1148 (2011)CrossRefGoogle Scholar
  21. [21]
    Mndange-Pfupfu A, Ciston J, Eryilmaz O, Erdemir A, Marks L. Direct observation of tribochemically assisted wear on diamond-like carbon thin films. Tribol Lett49: 351–356 (2013)CrossRefGoogle Scholar
  22. [22]
    Zilibotti G, Righi M C, Ferrario M. Ab initio study on the surface chemistry and nanotribological properties of passivated diamond. Phys Rev B79: 075420 (2009)CrossRefGoogle Scholar
  23. [23]
    Zilibotti G, Corni S, Righi M C. Load-induced confinement activates diamond lubrication by water. Phys Rev Lett111: 146101 (2013)CrossRefGoogle Scholar
  24. [24]
    Brenner D W, Shenderova O A, Harrison J A, Stuart S J, Ni B, Sinnott S B. A secondgeneration reactive empirical bond order (REBO) potential energy expression for hydrocarbons. J Phys: Condens Matter14: 783–802 (2002)Google Scholar
  25. [25]
    Pastewka L, Pou P, Pérez R, Gumbsch P, Moseler M. Describing bond-breaking processes by reactive potentials: The importance of an environment-dependent interaction range. Phys Rev B78: 161402(R) (2008)CrossRefGoogle Scholar
  26. [26]
    Pastewka L, Mrovec M, Moseler M, Gumbsch P. Bond order potentials for fracture, wear and plasticity. MRS Bulletin37: 493–503 (2012)CrossRefGoogle Scholar
  27. [27]
    Pastewka L, Klemenz A, Gumbsch P, Moseler M. Screened empirical bond-order potentials for Si-C. Phys Rev B87: 205410 (2013)CrossRefGoogle Scholar
  28. [28]
    Nayak P R. Random process model of rough surfaces. J Tribol93: 398–407 (1971)Google Scholar
  29. [29]
    Greenwood J A. A unified theory of surface roughness. Proc R Soc Lond A393: 133–157 (1984)CrossRefGoogle Scholar
  30. [30]
    Bitzek E, Koskinen P, Gähler F, Moseler M, Gumbsch P. Structural relaxation made simple. Phys Rev Lett97: 170201 (2006)CrossRefGoogle Scholar
  31. [31]
    Allen M P, Tildesley D J. Computer Simulation of Liquids. New York: Oxford University Press, 1989.Google Scholar
  32. [32]
    Stuart S J, Tutein A B, Harrison J A. A reactive potential for hydrocarbons with intermolecular interactions. J Chem Phys112: 6472–6486 (2000)CrossRefGoogle Scholar
  33. [33]
    Soddemann T, Dunweg B, Kremer K. Dissipative particle dynamics: A useful thermostat for equilibrium and nonequilibrium molecular dynamics simulations. Phys Rev E68: 46702 (2003)CrossRefGoogle Scholar
  34. [34]
    Hoogerbrugge P J, Koelman J M V A. Simulating microscopic hydrodynamic phenomena with dissipative particle dynamics. Europhys Lett19: 155–160 (1992)CrossRefGoogle Scholar
  35. [35]
    Ferrari A C, Robertson J. Interpretation of Raman spectra of disordered and amorphous carbon. Phys Rev B61: 14095 (2000)CrossRefGoogle Scholar
  36. [36]
    Franzblau D S. Computation of ring statistics for network models of solids. Phys Rev B44: 4925–4930 (1991).CrossRefGoogle Scholar
  37. [37]
    Fu X-Y, Falk M L, Rigney D A. Sliding behavior of metallic glass—Part II. Computer simulations. Wear250: 420–430 (2001)CrossRefGoogle Scholar
  38. [38]
    Fu X-Y, Rigney D A, Falk M L. Sliding and deformation of metallic glass: experiments and MD simulations. J Non- Cryst Solids317: 206–214 (2003)CrossRefGoogle Scholar
  39. [39]
    Pastewka L, Moser S, Moseler M, Blug B, Meier S, T Hollstein, P Gumbsch. The running-in of amorphous hydrocarbon tribocoatings: A comparison between experiment and molecular dynamics simulations. Int J Mat Res99: 1136–1143 (2008).CrossRefGoogle Scholar
  40. [40]
    Pastewka L, Peguiron J, Gumbsch P, Moseler M. Molecular dynamics simulation of gold solid film lubrication. Int J Mat Res101: 981–988 (2010)CrossRefGoogle Scholar
  41. [41]
    Pastewka L, Moser S, Gumbsch P, Moseler M. Anisotropic mechanical amorphization drives wear in diamond. Nature Mater10: 34–38 (2011)CrossRefGoogle Scholar
  42. [42]
    Falk M L. Molecular-dynamics study of ductile and brittle fracture in model noncrystalline solids. Phys Rev B60: 7062–7070 (1999)CrossRefGoogle Scholar
  43. [43]
    Falk M L, Langer J S. From simulation to theory in the physics of deformation and fracture. MRS Bull20: 40–45 (2000)CrossRefGoogle Scholar
  44. [44]
    Erdemir, A. Private communication.Google Scholar
  45. [45]
    Stukowski A. Visualization and analysis of atomistic simulation data with OVITO-The open visualization tool. Modelling Simul Mater Sci Eng18: 015012 (2010)CrossRefGoogle Scholar

Copyright information

© The author(s) 2014

This article is published under license to BioMed Central Ltd. Open Access This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited

Authors and Affiliations

  • Pedro A. Romero
    • 1
  • Lars Pastewka
    • 1
    • 2
  • Julian Von Lautz
    • 1
  • Michael Moseler
    • 1
    • 3
    • 4
  1. 1.Fraunhofer Institute for Mechanics of Materials IWMFreiburgGermany
  2. 2.Karlsruhe Institute of TechnologyIAM-ZBSKarlsruheGermany
  3. 3.Freiburg Materials Research CenterFreiburgGermany
  4. 4.Physics DepartmentUniversity of FreiburgFreiburgGermany

Personalised recommendations