Changes of phase composition of Zr_(1-x)(Ce/Y)_xO_2 complex oxides induced by thermal treatment

摘要

The medical prosthesis components made from (ZrO_2)-based ceramics present a good biocompatibility as well as especially mechanical properties. Much more, the problems of nondestructive evaluation for these elements, which assure both comfort and maximum safety to the patient, are imperative for these medical implants. In this study, we investigate the structure and the mechanical properties of Zr_(1-x)(Ce/Y)_xO_2, (x=0.0;0.09;0.13;0.17) materials as well as the modification of their crystallographic structure due to various thermal treatments and variation of Ce/Y concentrations in the samples. The substitution of Zr with Ce and the thermal treatment at 1000°C produced important transformation in the phase composition and the microstructure of the sample. A large decrease of the microstrains was observed at the treated samples. Combining characterization techniques based on XRD and ND with non-destructive evaluation methods based on Resonant Ultrasound Spectroscopy (RUS) and Acoustic Emission (AE), we emphasize a unique approach on evaluating the physical properties of these ceramics. Performed evaluation tests of Zr_(1-x)(Ce/Y)_xO_2 ceramics have shown big influence of composition on their fracture behavior and resulting strength due to different damage mechanisms.