MICROSTRUCTURAL OBSERVATIONS OF 2 DEFORMED PARTIALLY-STABILIZED ZIRCONIA CERAMICS USING ACOUSTIC MICROSCOPY

Ceramics containing zirconia exhibit increased fracture toughness because of the transformation mechanism. Because the acoustic microscope yields contrast at regions of differing elastic properties, it is possible to obtain unique information from these regions. Acoustic micrographs of phase-transformed regions surrounding Vickers indentations showed contrast within grains. Radial cracks were strongly visible, while up to five types of line contrast have been imaged. Much of the contrast in the acoustic micrographs is interpreted in terms of the interaction between Rayleigh waves and the microstructure of the zirconia ceramic. Line-contrast types A and B are accounted for in the literature while types C-E are new.