Subeutectoid Degradation of Yttria‐Stabilized Tetragonal Zirconia Polycrystal and Ceria‐Doped Yttria‐Stabilized Tetragonal Zirconia Polycrystal Ceramics
1991; Wiley; Volume: 74; Issue: 6 Linguagem: Inglês
10.1111/j.1151-2916.1991.tb04094.x
ISSN1551-2916
AutoresMaría Teresa Tejedor Hernández, J. R. Jurado, P. Durän, J.L.G. Fierro,
Tópico(s)Glass properties and applications
ResumoYttria‐doped tetragonal zirconia containing 2 and 3 mol% Y 2 O 3 (Y‐TZP), and CeO 2 ‐doped Y‐TZP containing 0 to 12 mol% CeO 2 were sintered at 1350°C in a tetragonal single‐phase field for 2 h in air, and the degradation behavior at low temperature in air and in hot water was observed. X‐ray photoelectron spectroscopy studies on the surface of hydrothermally treated samples show evidence for the formation of a YO(OH) species, along with the simultaneous formation of purely tetragonal zirconia nuclei that retain their coherence in the Y‐TZP matrix. Above a critical size, the tetragonal nuclei spontaneously transform to a monoclinic structure, giving rise to macro‐ and microcracking. The strong tetragonal grains degrade to produce a spalling phenomenon that facilitates further degradation. Y‐TZP ceramics alloyed with adequate amounts of CeO 2 show no tetragonal‐to‐monoclinic transformation after hydrothermal treatment.
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