Fine zirconia powders were prepared by hydrothermal crystallization of amorphous zirconia and hydrothermal oxidation of Zr metal, both recently developed in our laboratory. In hydrothermal crystallization, metastable tetragonal ZrO//2 was formed only from the amorphous phase. Hydrothermal oxidation of Zr metal by pure water yielded monoclinic ZrO//2. When Ca solutions were used, fine cubic zirconia grains were partially formed in addition to monoclinic zirconia, particularly in the case of Ca(NO//3)//2 solutions with excess Zr metal at 700 degree C. This cubic zirconia was stabilized by calcium and nitrogen. Y(NO//3)//3 or NH//4NO//3 solutions also yielded a small amount of cubic zirconia phase.
|Number of pages||12|
|Journal||Report of the Research Laboratory of Engineering Materials Tokyo|
|Publication status||Published - 1984 Jan 1|
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