An investigation of microhardness anisotropy in cobalt single crystals

Abstract

Microhardness measurements have been made, using Vickers and Knoop indenters, on cobalt single crystals of various orientations. The observed hardness variations have been compared with the predictions of previous microhardness theories, and also with a simple theory developed in this paper. It is shown that on planes of high symmetry the results for Knoop indentation are more consistent with compressive forces in the indented material than with tensile forces. The Knoop results for planes of low symmetry and the Vickers results for all planes are not as predicted by any of the current theories.