Determining the Fracture Toughness of Alumina Ceramics from Vickers Indentations

Abstract Many methods are currently used to measure fracture toughness of ceramic materials. Due to its simplicity, its non-destructive nature, and the fact that minimal machining is required to prepare the sample, the use of the Vickers hardness indentations to measure fracture toughness (KI C) has become quite popular. The aim of the present work is to investigate the hardness from Vickers indentations and the fracture toughness based on crack-length measurements of cracks introduced into the sample surface of cold isostatically pressed (CIP)-Al2O3 with 99.8% purity.