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Friction of metal-matrix self-lubricating composites: Relationships among lubricant content, lubricating film coverage, and friction coefficient

  • Jinkun XiaoEmail author
  • Yuqing Wu
  • Wei Zhang
  • Juan Chen
  • Chao Zhang
Open Access
Research article


Metal-matrix self-lubricating composites can exhibit excellent tribological properties owing to the release of solid lubricant from the matrix and the formation of a lubricating film on the tribosurface. The coverage of the lubricating film on a worn surface significantly influences the sliding process. However, it is difficult to quantify the film coverage owing to the thin and discontinuous character of the lubricating film and the high roughness of the worn surface. A quantitative characterization of the lubricating film coverage based on X-ray photoelectron spectroscopy (XPS) analysis was developed in this study. The friction tests of Cu-MoS2 composites with a MoS2 content of 0–40 vol% were conducted, and the worn surfaces of the composites were observed and analyzed. Further, the influence of the MoS2 volume content on the coverage of the lubricating film on the worn surface was investigated. The relationships among the volume fraction of the lubricant, coverage of the lubricating film, and the friction coefficient were established. The friction model for the metal matrix self-lubricating composites was developed and verified to facilitate the composition design and friction coefficient prediction of self-lubricating composites.


self-lubricating composites friction coefficient lubricating film XPS 



The authors would like to thank the National Natural Science Foundation of China (Grant No. 51804272), Natural Science Foundation of Jiangsu Province (Grant No. BK20160472), Natural Science Foundation of the Jiangsu Higher Education Institutions of China (Grant No. 17KJB460017), Project funded by China Postdoctoral Science Foundation (Grant No. 2018M640526), Jiangsu Planned Projects for Postdoctoral Research Funds (Grant No. 1601095C and 2018K073C), Postgraduate Research & Practice Innovation Program of Jiangsu Province (Grant No. SJCX17_0623), Marine Science and Technology Project of Jiangsu Province (Grant No. HY2017-10), Cooperation Funding of Yangzhou City-Yangzhou University (Grant No. YZU201722), and Jiangdu Advanced Equipment Engineering Institute of Yangzhou University (Grant No. 2017-01) for the financial support provided.


  1. [1]
    Su Y F, Zhang Y S, Song J J, Hu L T. Tribological behavior and lubrication mechanism of self-lubricating ceramic/metal composites: The effect of matrix type on the friction and wear properties. Wear 372–373: 130–138 (2017)CrossRefGoogle Scholar
  2. [2]
    Sharma S M, Anand A. Solid lubrication in iron based materials-a review. Tribol Ind 38(3): 318–331 (2016)Google Scholar
  3. [3]
    De Mello J D B, Binder C, Hammes G, Binder R, Klein A N. Tribological behaviour of sintered iron based self-lubricating composites. Friction 5(3): 285–307 (2017)CrossRefGoogle Scholar
  4. [4]
    Scharf T W, Prasad S V. Solid lubricants: A review. J Mater Sci 48(2): 511–531 (2013)CrossRefGoogle Scholar
  5. [5]
    Chhowalla M, Amaratunga G A J. Thin films of fullerenelike MoS2 nanoparticles with ultra-low friction and wear. Nature 407(6801): 164–167 (2000)CrossRefGoogle Scholar
  6. [6]
    Wang W, Xie G X, Luo J B. Black phosphorus as a new lubricant. Friction 6(1): 116–142 (2018)CrossRefGoogle Scholar
  7. [7]
    Shiao S J, Wang T Z. Dry self-lubricating composites. Compos: Part B 27(5): 459–465 (1996)CrossRefGoogle Scholar
  8. [8]
    Xiao J K, Zhang L, Zhou K C, Wang X P. Microscratch behavior of copper-graphite composites. Tribol Int 57: 38–45 (2013)CrossRefGoogle Scholar
  9. [9]
    Mahathanabodee S, Palathai T, Raadnui S, Tongsri R, Sombatsompop N. Dry sliding wear behavior of SS316L composites containing h-BN and MoS2 solid lubricants. Wear 316(1–2): 37–48 (2014)CrossRefGoogle Scholar
  10. [10]
    Kováčik J, Emmer Š, Bielek J, Keleši L. Effect of composition on friction coefficient of Cu-graphite composites. Wear 265(3–4): 417–421 (2008)CrossRefGoogle Scholar
  11. [11]
    Akhlaghi F, Zare-Bidaki A. Influence of graphite content on the dry sliding and oil impregnated sliding wear behavior of Al 2024-graphite composites produced by in situ powder metallurgy method. Wear 266(1–2): 37–45 (2009)CrossRefGoogle Scholar
  12. [12]
    Wu Y X, Wang F X, Cheng Y Q, Chen N P. A study of the optimization mechanism of solid lubricant concentration in NiMoS2 self-lubricating composite. Wear 205(1–2): 64–70 (1997)CrossRefGoogle Scholar
  13. [13]
    Xiao J K, Zhang W, Liu L M, Zhang L, Zhang C. Tribological behavior of copper-molybdenum disulfide composites. Wear 384–385: 61–71 (2017)CrossRefGoogle Scholar
  14. [14]
    Rohatgi P K, Liu Y, Yin M, Barr T L. Tribological behavior and surface analysis of tribodeformed AI alloy-50 pet graphite particle composites. Metall Trans A 22(6): 1435–1441 (1991)CrossRefGoogle Scholar
  15. [15]
    Axén N, Hutchings I M, Jacobson S. A model for the friction of multiphase materials in abrasion. Tribol Int 29(6): 467–475 (1996)CrossRefGoogle Scholar
  16. [16]
    van Trinh P, Trung T B, Thang N B, Thang B H, Tinh T X, Quang L D, Phuong D D, Minh P N. Calculation of the friction coefficient of Cu matrix composite reinforced by carbon nanotubes. Comp Mater Sci 49(4 Suppl 1): S239–S241 (2010)CrossRefGoogle Scholar
  17. [17]
    Song J P, Valefi M, de Rooij M, Schipper D J. A mechanical model for surface layer formation on self-lubricating ceramic composites. Wear 268(9–10): 1072–1079 (2010)CrossRefGoogle Scholar
  18. [18]
    Valefi M, de Rooij M, Mokhtari M, Schipper D J. Modelling of a thin soft layer on a self-lubricating ceramic composite. Wear 303(1–2): 178–184 (2013)CrossRefGoogle Scholar
  19. [19]
    Xu Z S, Zhang Q X, Huang X J, Liu R, Zhai W Z, Yang K, Zhu Q S. An approximate model for the migration of solid lubricant on metal matrix self-lubricating composites. Tribol Int 93: 104–114 (2016)CrossRefGoogle Scholar
  20. [20]
    Bowden F P, Tabor D. The Friction and Lubrication of Solids. Oxford (UK): Clarendon Press, 1964.zbMATHGoogle Scholar
  21. [21]
    Sawyer W G, Dickrell P L. A fractional coverage model for gas-surface interaction in reciprocating sliding contacts. Wear 256(1–2): 73–80 (2004)CrossRefGoogle Scholar
  22. [22]
    Pudjoprawoto R, Dougherty P, Higgs III C F. A volumetric fractional coverage model to predict frictional behavior for in situ transfer film lubrication. Wear 304(1–2): 173–182 (2013)CrossRefGoogle Scholar
  23. [23]
    Wornyoh E Y A, Higgs III C F. An asperity-based fractional coverage model for transfer films on a tribological surface. Wear 270(3–4): 127–139 (2011)CrossRefGoogle Scholar
  24. [24]
    Blanchet T A, Sawyer W G. Differential application of wear models to fractional thin films. Wear 251(1–12): 1003–1008 (2001)CrossRefGoogle Scholar
  25. [25]
    Ye J, Khare H S, Burris D L. Quantitative characterization of solid lubricant transfer film quality. Wear 316(1–2): 133–143 (2014)CrossRefGoogle Scholar
  26. [26]
    Haidar D R, Ye J, Moore A C, Burris D L. Assessing quantitative metrics of transfer film quality as indicators of polymer wear performance. Wear 380–381: 78–85 (2017)CrossRefGoogle Scholar
  27. [27]
    Cao H Q, Qian Z Y, Zhang L, Xiao J K, Zhou K C. Tribological behavior of Cu matrix composites containing graphite and tungsten disulfide. Tribol Trans 57(6): 1037–1043 (2014)CrossRefGoogle Scholar
  28. [28]
    Zhang L, Xiao J K, Zhou K C. Sliding wear behavior of silver-molybdenum disulfide composite. Tribol Trans 55(4): 473–480 (2012)CrossRefGoogle Scholar
  29. [29]
    Rohatgi P K, Liu Y, Yin M, Barr T L. A surface-analytical study of tribodeformed aluminum alloy 319-10 vol.% graphite particle composite. Mater Sci Eng A 123(2): 213–218 (1990)CrossRefGoogle Scholar
  30. [30]
    Mandrino D, Podgornik B. XPS investigations of tribofilms formed on CrN coatings. Appl Surf Sci 396: 554–559 (2017)CrossRefGoogle Scholar
  31. [31]
    Blau P J, Yust C S. Microfriction studies of model selflubricating surfaces. Surf Coat Technol 62(1–3): 380–387 (1993)CrossRefGoogle Scholar
  32. [32]
    Ma W L, Lu J J. Effect of surface texture on transfer layer formation and tribological behaviour of copper-graphite composite. Wear 270(3-4): 218–229 (2011)CrossRefGoogle Scholar
  33. [33]
    Wilson J E, Stott F H, Wood G C. The development of wearprotective oxides and their influence on sliding friction. Proc Roy Soc A: Mathem, Phys Eng Sci 369(1739): 557–574 (1980)CrossRefGoogle Scholar
  34. [34]
    Ghods P, Isgor O B, Brown J R, Bensebaa F, Kingston D. XPS depth profiling study on the passive oxide film of carbon steel in saturated calcium hydroxide solution and the effect of chloride on the film properties. Appl Surf Sci 257(10): 4669–4677 (2011)CrossRefGoogle Scholar
  35. [35]
    Chasoglou D, Hryha E, Norell M, Nyborg L. Characterization of surface oxides on water-atomized steel powder by XPS/AES depth profiling and nano-scale lateral surface analysis. Appl Surf Sci 268: 496–506 (2013)CrossRefGoogle Scholar
  36. [36]
    Busby Y, List-Kratochvil E J W, Pireaux J J. Chemical analysis of the interface in bulk-heterojunction solar cells by X-ray photoelectron spectroscopy depth profiling. ACS Appl Mater Interfaces 9(4): 3842–3848 (2017)CrossRefGoogle Scholar
  37. [37]
    Baker M A, Gilmore R, Lenardi C, Gissler W. XPS investigation of preferential sputtering of S from MoS2 and determination of MoSx stoichiometry from Mo and S peak positions. Appl Surf Sci 150(1–4): 255–262 (1999)CrossRefGoogle Scholar
  38. [38]
    Steinberger R, Walter J, Greunz T, Duchoslav J, Arndt M, Molodtsov S, Meyer D C, Stifter D. XPS study of the effects of long-term Ar+ ion and Ar cluster sputtering on the chemical degradation of hydrozincite and iron oxide. Corros Sci 99: 66–75 (2015)CrossRefGoogle Scholar

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Authors and Affiliations

  • Jinkun Xiao
    • 1
    • 2
    Email author
  • Yuqing Wu
    • 1
  • Wei Zhang
    • 1
  • Juan Chen
    • 3
  • Chao Zhang
    • 1
  1. 1.College of Mechanical EngineeringYangzhou UniversityYangzhouChina
  2. 2.College of Chemistry and Chemical EngineeringYangzhou UniversityYangzhouChina
  3. 3.Testing CenterYangzhou UniversityYangzhouChina

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