Abstract
440C steel thrust ball bearing races lubricated with 1 μm thick sputtered films of MoS2 were tested in the unidirectional and oscillatory modes against bare steel balls in moderate (10−4−10−5 Pa ≈ 10−6−10−7 Torr) vacuum and in 1 atmosphere of 99.999% pure (⩽ 1 ppm water) N2 in the same unbaked environmental chamber. Over 90% of the residual gases in the chamber vacuum consisted of H2O vapor. The bearings operated in N2 showed substantially longer lives compared to the specimens tested in vacuum. Scanning electron microscope (SEM) tribometry was also performed on an MoS2 film powder-burnished onto a 440C flat. This flat was repeatedly oscillated against bare, hemispherical-tipped 440C pins on fresh wear tracks in the same type of N2 and column vacuum of ~10−3 Pa ≈ 10−5 Torr itself containing over 90% residual H2O. The SEM-generated results on the burnished film confirmed the same, atmosphere-dependent difference in wear life observed with the sputtered layers. Varying the moisture content of the burnished flat and its immediate environment by cryosorption predictably manipulated the coefficient of friction and wear life of MoS2. The various possible causes of this perplexing phenomenon are reviewed, and a plausible hypothesis is offered attributing the unexpected wear life reduction to the physico-chemical consequences of residual H2O hydrogen-bonding to the oxidized and/or hydrated edge and basal plane sites of MoS2 in moderate vacuum. The site-specific sorption of water is severely hindered in 1 atm N2 by the gas molecules disrupting the H-bonding mechanism.
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References
E.W. Roberts, in: Space Mechanisms and Tribology, Proc. 4th European Symp. (ESA SP-299, March 1990) p. 59.
E.W. Roberts, Thin Solid Films 181 (1989) 461.
T. Spalvins, NASA TM-105292 (1991).
P.D. Fleischauer and M.R. Hilton, in: New Materials Approaches to Tribology: Theory and Applications, Mater. Res. Soc. Proc., Vol. 140, eds. L.E. Pope, L.L. Fehrenbacher and W.O. Winer (Pittsburgh, 1989) p. 9.
R.A. Rowntree and M.J. Todd, in: New Materials Approaches to Tribology: Theory and Applications, Mater. Res. Soc. Proc., Vol. 140, eds. L.E. Pope, L.L. Fehrenbacher and W.O. Winer (Pittsburgh, 1989) p. 21.
M.R. Hilton and P.D. Fleischauer, Surf. Coat. Technol. 54/55 (1992) 435.
D.E. Peebles and J.A. Ohlhousen, Sandia Rept. No. SAND-92–0052, Sandia National Labs, Albuquerque, NM, May 1992.
P.D. Fleischauer and R. Bauer, Tribol. Trans. 31 (1988) 239.
S.V. Didziulis, M.R. Hilton, R. Bauer and P.D. Fleischauer, Aerospace Report No. TOR-92(2064)-1, The Aerospace Corp., El Segundo, CA, 15 October 1992.
V. Buck, Thin Solid Films 139 (1986) 157.
M.R. Hilton, R. Bauer and P.D. Fleischauer, Thin Solid Films 188 (1990) 219.
M.R. Hilton and P.D. Fleischauer, in: New Materials Approaches to Tribology: Theory and Applications, Mater. Res. Soc. Proc., Vol. 140, eds. L.E. Pope, L.L. Fehrenbacher and W.O. Winer (Pittsburgh, 1989) p. 227.
J. Halling, ASME Trans. J. Basic Eng. March (1966) pp. 213–220.
M.N. Gardos, H.-S. Hong and W.O. Winer, Tribol. Trans. 33 (1990) 209.
M.N. Gardos, WRDC-TR-90–4096, Vol. 1, Hughes Aircraft Co., El Segundo, CA 90245, November 1990.
S.V. Didziulis, P.D. Fleischauer, B.L. Soriano and M.N. Gardos. Surf. Coat. Technol. 43/44 (1990) 652
M.N. Gardos, WL-TR-4089, Vol. 1, Hughes Aircraft Co., El Segundo, CA, August 1993.
M.N. Gardos, in: Synthetic Diamond: Emerging CVD Science and Technology, Electrochem. Soc. Monograph, eds. K.E. Spear and J.P. Dismukes (Wiley, New York, 1994) ch. 12, p. 419.
M.N. Gardos and K.V. Ravi, Dia. Films Technol. 4 (1994) 139.
M.N. Gardos, ASLE Trans. 17 (1974) 237.
M.R. Hilton, Surf. Coat. Technol. 68/69 (1994) 407.
G.B. Hopple, J.E. Keem and S.H. Loewenthal, Wear 162–164 (1993) 919.
J.M. Martin, C. Donnet, Thg. Le Mogne and Th. Epicier, Phys. Rev. B 48 (1993) 10, 583.
P. Arnoldy, J.C.M. de Jonge and J.A. Moulijn, J. Phys. Chem. 89 (1985) 4517.
R.J. Saykally and G.A. Blake, Science 259 (1993) 1570.
S. Ross and A. Sussman, J. Phys. Chem. 59 (1955) 889.
E.V. Ballou and S. Ross, J. Phys. Chem. 57 (1953) 653.
F.H. Stillinger, Science 209 (1980) 451.
B. Fubini, M. Volante, V. Bolis and E. Giamello, J. Mater. Sci. 24 (1989) 549.
R.R.M. Johnston and A.J.W. Moore, Wear 7 (1964) 498.
L.A. Bursill, Proc. Roy. Soc. A 311 (1969) 267.
W. Thöni and P.B. Hirsch, Phil. Mag. 33 (1976) 639.
R.K. Iler, The Chemistry of Silica (Wiley, New York, 1979) p. 651.
J.L. Keddie, P.V. Braun and E.P. Gianellis, J. Am. Ceram. Soc. 76 (1993) 2529.
Y. Kim and C.M. Lieber, Science 257 (1992) 375.
A.I. Brudnyi and A.F. Karmadonov, Wear 33 (1975) 243.
T.F. Hayden, J.A. Dumesic, R.D. Sherwood and R.T.K. Baker, J. Catal. 105 (1987) 299.
A. Vegiri and S.C. Farantos, J. Chem. Phys. 98 (1993) 4059.
R.P. Burns and D.E. Pierce, in: New Materials Approaches to Tribology: Theory and Applications, Mater. Res. Soc. Proc., Vol. 140, eds. L.E. Pope, L.L. Fehrenbacher and W.O. Winer (Pittsburgh, 1989) p. 377.
D.E. Pierce, R.P. Burns, H.M. Dauplaise and L.J. Mizerka, Tribol. Trans. 34 (1991) 205.
K.A. Ross and M.J. Westphal, J. Appl. Phys. 75 (1994) 408.
W.E. Carlos and M.W. Cole, Surf. Sci. 91 (1980) 339.
S. Suzuki, P.G. Green, R.E. Bumgardner, S. Dasgupta, W.W. Goddard III and G.A. Blake, Science 257 (1992) 942.
R. J. Good and E. Elbing, Ind. Eng. Chem. 62 (3) (1970) 54.
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Gardos, M.N. Anomalous wear behavior of MoS2 films in moderate vacuum and dry nitrogen. Tribol Lett 1, 67–85 (1995). https://doi.org/10.1007/BF00157977
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DOI: https://doi.org/10.1007/BF00157977