On the interpretation of the indentation size effect (ISE) through gradient theory for Vickers and Berkovich indenters

Abstract

The so-called indentation size effect (ISE) observed mainly in nanoindentation measurements with prismatic tips, is theoretically modeled in this article with the use of gradient theory. It is shown that the ISE, i.e. the dependence of the calculated hardness value on the indentation depth, is rather an artifact of the geometry of the tip used, than a phenomenon related to the material tested. The model predictions are compared with nanoindentation measurements of Al specimens.

Keywords

• indentation size effect
• nanoindentation
• vickers indentation