Abstract
Continuous microindentation tests performed on the electropolished surfaces of single crystal Fe (3 wt. % Si), known to have a thin passivation film, show a sharp discontinuity at a load of 1.8 mN. To this point, there was no apparent plastic deformation in the metal in that the loading and unloading curves exactly overlay each other. Stresses at the discontinuity were close to the theoretical strength of the metal. Elastic contact theories of Hertz and Love reproduced the elastic portion of the load-displacement curves. On removing the passivation film with a HCl solution, indentation tests yielded strengths nearly two orders of magnitude smaller. The strength recovered to near its initial value after the liquid evaporated and the passivation film re-formed.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 685-688 |
| Number of pages | 4 |
| Journal | Journal of Materials Research |
| Volume | 8 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 1993 |
Bibliographical note
Funding Information:This research was supported by the Center for Interfacial Engineering at the University of Minnesota under Grant No. NSF/CDR-8721551 and Corning Incorporated, under Grant No. N00014-89-0164. The authors thank Dr. P. S. Alexopoulos, Dr. T. W. Wu, and Dr. T. C. O'Sullivan, of IBM Almaden Research Center, and Dr. Ridha Berriche of the National Research Council, Canada, for building the microindentation apparatus.