Abstract
Polycrystalline, tetragonal (t′) zirconia samples containing 3 and 4 mol% yttria were fabricated by annealing pressureless‐sintered samples in air at ∼ 2100°C for 15 min. The grain size of these fully tetragonal samples was on the order of 100 to 200 μm. Domain structure of the samples and of a 3‐mol%‐yttria‐doped tetragonal zirconia single crystal was examined by transmission optical microscopy under polarized light and by transmission electron microscopy. The orientations of the domain/colony boundaries were in accord with the predictions of group theory. As‐polished surfaces of polycrystalline t′ materials showed no monoclinic phase even after 1000 h at 275°C in air. By contrast, conventionally yttria‐doped tetragonal zirconia polycrystalline (Y‐TZP) ceramics of grain size >0.5 μm showed substantial transformation. Surface grinding enhanced the resistance to degradation of Y‐TZP but decreased that of t′ materials. Even then, the t′ materials exhibited better resistance to degradation than the Y‐TZP ceramics. Excellent resistance of the t′ materials to low‐temperature aging despite a very large grain size and the opposite effect of grinding on phase stability are all explained on the basis of ferroelastic domain structure of these materials.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
