In-situ study of mechanical damage evolution of segmented ceramic using digital image correlation

Failure mechanism of Al2O3 ceramics with a segmented structure and a pore volume of 50% under compression was investigated. The structure segmentation was achieved by forming multi-level porosity which includes large and small pores, as well as an extensive network of pore channels. The images were registered with Nikon D90 camera at frame rate of 1/3 fps. The full-field displacement set was measured. It was demonstrated that DIC algorithm can be applied to investigate the ceramics fracture without special optics. It was found that cracks, initiated in some regions of the material, were active there for some time. The experiment proved that the ceramics is tolerant to macro-crack owing to evolution of micro- and mesocracks. The macrocrack formation is demonstrated by the deformation structures.