Relationship between the fracture toughness evaluated by the IF (indentation fracture) method and the crack morphology in ceramics

Abstract

Fracture toughness was measured by the indentation fracture (IF) method on brittle materials such as ceramics including alumina and zirconia in this study. A discussion was then made on the relationship between the fracture toughness and the fractal dimension of the indentation crack that was estimated by the box-counting method. The fracture toughness of brittle materials increased with increasing the fractal dimension, namely, with increasing the complexity of crack morphology. Further, a unique relationship was found between the fracture toughness and the fractal dimension, irrespective of the kinds of ceramics. The relationship between fractal nature of cracks and microstructures of the materials was also discussed.