Fatigue damage mechanisms in CeO2 stabilized tetragonal ZrO2

Abstract

Hertzian indentation studies, where an indenting sphere is subjected to single-cycle or repeated loading on a flat ceramic specimen surface, have provided useful insights into contact damage accumulation and fatigue processes at the scale of the microstructure (short-crack region) in numerous ceramic-based systems [1–3]. The nature of the degradation has been shown to be strongly dependent on the material microstructure. In homogeneous, fine-grained ceramic microstructures conical cracks form in the region of limited tension around the contact circle whereas in heterogeneous, coarse-grained microstructures, distributed shear faults develop within a subsurface zone of compression-shear beneath the contact [4]. Cyclic loading of toughened heterogeneous ceramics readily exhibit cumulative damage events at the microscale, leading to strength degradation and material removal [2, 5, 6]. Consequently, the Hertzian test is relevant to assessing fatigue damage mechanisms and evolution on a localized level in ceramics. © 2002 Springer Nature Switzerland AG.