Tribology Letters

, Volume 18, Issue 4, pp 437–443

Hyperthermal atomic oxygen interaction with MoS2 lubricants and relevance to space environmental effects in low earth orbit – effects on friction coefficient and wear-life

  • M. Tagawa
  • M. Muromoto
  • S. Hachiue
  • K. Yokota
  • N. Ohmae
  • K. Matsumoto
  • M. Suzuki
Article

DOI: 10.1007/s11249-004-3594-1

Cite this article as:
Tagawa, M., Muromoto, M., Hachiue, S. et al. Tribol Lett (2005) 18: 437. doi:10.1007/s11249-004-3594-1

Wear-life of the MoS2 film was evaluated by in situ tribological testing under 5 eV atomic oxygen exposures which simulated atomic oxygen environment in low Earth orbit. A combination of a laser-detonation atomic oxygen source and a conventional pin-on-disk friction tester was used to perform tribological tests. It was confirmed that the friction coefficient was not affected by atomic oxygen exposure when atomic oxygen fluence was low; however, the friction coefficient increased with increasing atomic oxygen fluence and it reached as high as 0.05 at the atomic oxygen fluence of 3.4 × 1016 atoms/cm2/cycle (nine times larger than the normal value). Effect of atomic oxygen on the wear-life of the film has much more drastic. With atomic oxygen fluence of 1.7 × 1016 atoms/cm2/cycle, wear-life of the film was reduced less than one-tenth of that during ex situ testing result of the same film. It was also observed that the wear-life of the film was inversely proportional to the atomic oxygen fluence between sliding passes.

Keywords:

atomic oxygen MoS2 space environmental effect tribology low earth orbit lubricant 

Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  • M. Tagawa
    • 1
  • M. Muromoto
    • 1
  • S. Hachiue
    • 1
  • K. Yokota
    • 1
  • N. Ohmae
    • 1
  • K. Matsumoto
    • 2
  • M. Suzuki
    • 2
  1. 1.Department of Mechanical EngineeringKobe UniversityNadaJapan
  2. 2.Japan Aerospace Exploration AgencyJindaiji-HigashiChofuJapan

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