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Effect of Ga 2 O 3 on Sintering and Phase Stability of Sc 2 O 3 ‐Doped Tetragonal Zirconia Prepared via Aqueous Solution Route
Author(s) -
Hirano Masanori,
Kojima Hideo,
Minami Hideaki
Publication year - 2015
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/jace.13291
Subject(s) - sintering , cubic zirconia , monoclinic crystal system , materials science , tetragonal crystal system , phase (matter) , zirconium , hydrothermal circulation , ceramic , aqueous solution , chemical engineering , analytical chemistry (journal) , nuclear chemistry , mineralogy , crystallography , composite material , crystal structure , metallurgy , chemistry , organic chemistry , engineering
The effects of the presence of Ga 2 O 3 on low‐temperature sintering and the phase stability of 4, 5, and 6 mol% Sc 2 O 3 ‐doped tetragonal zirconia ceramics (4 ScSZ , 5 ScSZ , and 6 ScSZ , respectively) were investigated. A series of zirconia sintered bodies with compositions ( ZrO 2 ) 0.99− x ( Sc 2 O 3 ) x ( Ga 2 O 3 ) 0.01 , x = 0.04, 0.05, and 0.06 was fabricated by sintering at 1000°C to 1500°C for 1 h using fine powders that were prepared via the combination of homogeneous precipitation method and hydrolysis technique using monoclinic zirconia sols synthesized through the forced hydrolysis of an aqueous solution of zirconium oxychloride at 100°C for 168 h. The presence of 1 mol% Ga 2 O 3 was effective in reducing sintering temperature necessary to fabricate dense bodies and enabled to obtain dense sintered bodies via sintering at 1100°C for 1 h. The phase stability, that is, low‐temperature degradation behavior of the resultant zirconia ceramics was determined under hydrothermal condition. The zirconia ceramics codoped with 1 mol% Ga 2 O 3 and 6 mol% Sc 2 O 3 (1 Ga 6 ScZ ) fabricated via sintering at 1300°C for 1 h showed high phase stability without the appearance of monoclinic zirconia phase, that is the tetragonal‐to‐monoclinic phase transformation was not observed in the 1 Ga 6 ScZ after treatment under hydrothermal condition at 150°C for 30 h.