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Resistance to Low‐Temperature Degradation of Equimolar YO 1.5 –TaO 2.5 Stabilized Tetragonal ZrO 2 Ceramics in Air
Author(s) -
Shen Yang,
Clarke David R.
Publication year - 2010
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2010.03665.x
Subject(s) - tetragonal crystal system , monoclinic crystal system , materials science , annealing (glass) , ceramic , cubic zirconia , crystallite , yttria stabilized zirconia , atmospheric temperature range , mineralogy , phase (matter) , doping , analytical chemistry (journal) , crystallography , chemical engineering , crystal structure , composite material , metallurgy , chemistry , thermodynamics , organic chemistry , optoelectronics , physics , engineering
A narrow range of composition exists along the ZrO 2 –YTaO 4 quasi‐binary in which the tetragonal phase can be retained on cooling. Ceramics within this region, corresponding to equimolar YO 1.5 and TaO 2.5 stabilizer concentrations, have been subject to accelerated testing for their susceptibility to moisture‐induced low‐temperature degradation (LTD) by annealing in air at 200°C. No low‐temperature transformation from tetragonal to monoclinic phase was evident even after 400 h in the tetragonal YO 1.5 –TaO 2.5 –ZrO 2 ceramics, while 50% of tetragonal phase in a sintered 3 mol% Y 2 O 3 ‐doped ZrO 2 transformed into monoclinic after the same long‐term annealing. The results not only demonstrate the superiority in LTD of equimolar yttria–tantala‐doped zirconia (ZrO 2 ) but have important implications for the proposed mechanisms of LTD in polycrystalline ZrO 2 .