Fracture response of ceramic materials to indentation loading

摘要

The indentation technique is applied to the testing of two types of tool ceramics (alumina and silicon nitride). The course of cracks initiated at the indentation corners is analysed. Beside the basic mechanical properties (indentation fracture toughness K{sub}(IC), crack resistance W) the response of investigated tool ceramics to the repeated loading is evaluated. The relation between median/radial cracks and the lateral crack initiation is presented. The propagation of subsurface lateral cracks results in the chipping formation what represent the final stage of the fatigue durability. The microfractography analysis of chipping surfaces is presented.