Open AccessThe characterization of Vicker`s microhardness indentations and pile-up profiles as a strain-hardening microprobe
Author(s) -
Carlos Vinícius de Paes Santos,
G.R. Odette,
G.E. Lucas,
B. Schroeter,
D. Klinginsmith,
Takashi Yamamoto
Publication year - 1998
Language(s) - English
Resource type - Reports
DOI - 10.2172/595663
Subject(s) - indentation hardness , materials science , indentation , hardening (computing) , strain hardening exponent , composite material , vickers hardness test , plasticity , microprobe , pile , metallurgy , structural engineering , microstructure , mineralogy , geology , layer (electronics) , engineering
Microhardness measurements have long been used to examine strength properties and changes in strength properties in metals, for example, as induced by irradiation. Microhardness affords a relatively simple test that can be applied to very small volumes of material. Microhardness is nominally related to the flow stress of the material at a fixed level of plastic strain. Further, the geometry of the pile-up of material around the indentation is related to the strain-hardening behavior of a material; steeper pile-ups correspond to smaller strain-hardening rates. In this study the relationship between pile-up profiles and strain hardening is examined using both experimental and analytical methods. Vickers microhardness tests have been performed on a variety of metal alloys including low alloy, high Cr and austenitic stainless steels. The pile-up topology around the indentations has been quantified using confocal microscopy techniques. In addition, the indentation and pile-up geometry has been simulated using finite element method techniques. These results have been used to develop an improved quantification of the relationship between the pile-up geometry and the strain-hardening constitutive behavior of the test material