Evaluation of the fracture toughness of brittle hardening materials by Vickers indentation

Abstract

We propose a Vickers indentation cracking-based method for evaluating the fracture toughness of brittle materials exhibiting strain hardening. The approach is an extension of the recent method by Hyun et al. (2015) for non-hardening materials to hardening materials. The hardening material is simplified by an equivalent non-hardening material with an elevated modified yield strain so that the fracture toughness of a hardening material can be evaluated with the formula proposed by Hyun et al. The proposed extension is verified by comparison with experimental results from nanoindentation tests on Ge(100) and Si(100).