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Stable and Metastable Phase Relations in the System ZrO 2 ‐CaO
Author(s) -
HELLMANN JOHN R.,
STUBICAN VLADIMIR S.
Publication year - 1983
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.1151-2916.1983.tb15710.x
Subject(s) - eutectic system , solid solution , metastability , decomposition , diffraction , phase (matter) , materials science , electron diffraction , phase diagram , crystallography , analytical chemistry (journal) , mineralogy , chemistry , microstructure , metallurgy , physics , optics , organic chemistry , chromatography
The chemical equilibrium for the system ZrO 2 ‐CaO was rede termined for temperatures above ∼1000°C by heating reactive powders for extended periods of time. The eutectoid decom position of the cubic solid solution was found to occur at 1140°±40°C and 17.0±0.5 mol% CaO. Decomposition reac tions in sintered cubic solid solutions were studied using elec tron diffraction and transmission techniques. Decomposition follows metastable extensions of the boundary lines which sena rate two‐phase regions from the adjacent cubic solid solution region. The appearance of the diffuse diffraction features in the electron diffraction patterns of cubic solid solutions Seems to be associated with short‐range ordering of oxygen vacancies.‘Duo ordered phases, CaZr 4 O 9 and Ca 6 Zr 19 O 44 , were syn thesized and their upper limits of stability were determined to be 1235°±15° and 1355°±15°C, respectively.