PAPERS & REPORTS

Introduce technical papers and reports of IIT (Instrumented Indentation Technology) and correlated fields.

 

Title

Evaluating plastic flow properties by characterizing indentation size effect using a sharp indenter

Author

Ju-Yong Kim a,*, Seung-Kyun Kang b, Julia R. Greer a, Dongil  Kwon b

a Material Science, California Institute of Technology, Pasadena, CA 91125, USA

b Department of Materials Science and Engineering Seoul National University, Seoul 151-744, Republic of Korea

Press and Date of publication

Received 6 December 2007; received in revised form 28 January 2008; accepted 5 February 2008

Available online 21 April 2008

Abstract

The strain-hardening exponent, used in describing the plastic flow properties of materials, is evaluated from the characteristic length in the indentation size effect (ISE). A linear relationship is fount between the strain-hardening exponent and the log of the ISE characteristic length for Ni and SCM21 (structural steel) samples with different plastic pre-strain values. These results are explained through the Taylor dislocation hardening model and a representative stress-strain approach. A dimensionless function characterizing the plastic unique dimensionless function is studied for 22 metals.

© 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Keywords: Indentation size effect; Nanoindentationl Strain-hardening exponent Plastic flow properties