Atomic force microscope measurements of elastic-plastic indentation into an Fe-3 wt. % Si single crystal showed that the volume displaced to the surface is nearly equal to the volume of the cavity. The surface displacement profiles and plastic zone size caused by a 69 nm penetration of a Vickers diamond tip are reasonably represented by an elastic-plastic continuum model. Invoking conservation of volume, estimates of the number of dislocations emanating from the free surface are reasonably consistent with the number of dislocations that have formed in the plastic zone to represent an average calculated plastic strain of 0.044.
Bibliographical noteFunding Information:
This research was supported by the Center for Interfacial Engineering at the University of Minnesota under Grant No. NSF/CDR-8721551. Support from the Corrosion Center of the University of Minnesota and the Department of Energy, Basic Energy Sciences, Materials Science Division, Grant DE-FG02-88Er45337A003 is gratefully acknowledged.