Revealing tetragonal-to-monoclinic phase transformation in Y-TZP at an initial stage of low temperature degradation using grazing incident-angle X-ray diffraction measurement

Grazing incident-angle X-ray diffraction measurement was performed to observe the initial stage of tetragonal-to-monoclinic (t-m) phase transformation in 3 mol % Y2O3-stabilized tetragonal ZrO2 (3Y-TZP) body exposed to hot water at 140°C, i.e. low temperature degradation (LTD) aging treatment. In the 3Y-TZP body after LTD aging for longer than 15 min, small amount of monoclinic phase was detected, while the as-sintered specimen consisted of tetragonal phase. The monoclinic phase was observed only at the surface portion with the thickness of less than about 100 nm. The t-m transformation in 3Y-TZP in hot water initiated from the surface of the specimen.