A method to determine fracture toughness using cube-corner indentation

For the cube-corner indenter, an approximate linear relationship between the ratio of hardness (H) to reduced modulus (E(r)) and the ratio of unloading work (W(u)) to total loading work (W(t)) is confirmed by finite-element calculations and by experiments. Based on this relationship a convenient method to determine the fracture toughness (K(IC)) of brittle materials, especially for those at small scale, using cube-corner indentations is proposed. Finally, the method is calibrated by indentation experiments on a set of brittle materials. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.