Skip to main content Accessibility help
×
Home

Continuous Microindentation of Passivated Surfaces in Surface Active Media

  • Shankar K. Venkataraman (a1), He Huang (a1), David L. Kohlstedt (a2) and William .W. Gerberich (a1)

Abstract

Continuous microindentation tests on electropolished, single crystal Fe(3wt%Si) and Ni surfaces with thin passivation layers exhibit sharp discontinuities in the load-displacement behavior. At the discontinuity, which occurs at a load of 1.8 mN for Fe(3wt%Si) and 0.1 mN for Ni, stresses below the indenter were close to the theoretical strength of the corresponding metal. Microindentation tests performed to loads less than the discontinuity point showed an elastic load-unload behavior. On removing the passive film with a NaCl or HC1 solution, strengths are one to two orders of magnitude smaller in the presence of the chloride ions. On evaporation of the liquid, the load at the discontinuity returned to its initial value due to repassivation, indicative of a passivation oxide layer with varying thickness. This conclusion was verified by ellipsometry. Even though the elastic load-unload behavior on the passivated surface suggests elastic behavior, both elastic finite element and non-linear, elastic perfectly plastic finite element solutions strongly suggest that this might not be the case. Several suggestions as to the reasons for the deviation from continuum theory are presented.

Copyright

References

Hide All
1 Gane, N., Proc. Roy. Soc. Lond. A. 317, 367 (1970).
2 Smith, D.A. and Bowkett, K.M., Fourth European regional conference on electron microscopy, Vol. I, p. 261 (1968).
3 Gane, N. and Bowden, F.P., J. Appl. Phys. 39, 1432 (1968).
4 Venkataraman, S.K., Kohlstedt, D.L. and Gerberich, W.W., J. Mater. Res.,
5 Pethica, J.B. and Tabor, D., Surface Science 89, 182 (1979).
6 Oliver, W.C. and Pharr, G.M., J.Mater. Res., 7, 1564 (1992).
7 Timoshenko, and Goodier, , Theory of Elasticity, second edition (McGraw Hill publications, New York, 1951), pp. 93.
8 Johnson, K.L., Contact Mechanics (Cambridge University Press, 1985), pp. 9093, 111–114.
9 Montmitonnet, P., Edlinger, M.L. and Felder, E., J. Tribology 115, 10 (1993).
10 Venkataraman, S.K., Kohlstedt, D.L., and Gerberich, W.W., in preparation.

Continuous Microindentation of Passivated Surfaces in Surface Active Media

  • Shankar K. Venkataraman (a1), He Huang (a1), David L. Kohlstedt (a2) and William .W. Gerberich (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed