Evaluation of fracture resistance of ceramics: Edge fracture tests

Advanced oxide and nonoxide ceramics were tested by edge flaking with different indenters. Flaking toughness values obtained with the Rockwell indenter were shown to be practically proportional to fracture toughness values measured by the single edge V-notched beam (SEVNB) method. The discussed edge fracture (EF) method enabling the determination of fracture resistance of ceramics in small-size specimen tests was demonstrated to be appropriate for materials technology as well as for the evaluation of ceramics for dentistry, cutting tools, and like uses. Emphasis was placed on the results of investigation of chip scars formed upon flaking off the specimens with the Rockwell, Vickers, and Knoop indenters.