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Crystallization Exotherms of Zirconia‐Hafnia Mixtures
Author(s) -
Srinivasan Ram,
Davis Burtron H.
Publication year - 1990
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.1151-2916.1990.tb09833.x
Subject(s) - differential scanning calorimetry , crystallization , hafnia , exothermic reaction , anhydrous , materials science , precipitation , chemical engineering , cubic zirconia , phase (matter) , calorimetry , oxide , mineralogy , differential thermal analysis , analytical chemistry (journal) , chemistry , thermodynamics , metallurgy , organic chemistry , diffraction , ceramic , physics , meteorology , engineering , optics
Differential scanning calorimetry was used to study the crystallization behavior of ZrO 2 ‐HfO 2 mixtures. The materials prepared by admixing Zr(NO 3 ) 4 and Hf(NO 3 ) 4 exhibited a peak at 40 wt% Hf composition in the exothermic‐heat‐versus‐mixed‐oxide composition curve. In contrast, the materials prepared by precipitation from a solution prepared from anhydrous HfCl 4 and ZrC1 4 exhibited a gradual decrease in exothermic behavior with increasing Hf content. The temperature for the exotherm increased with increasing Hf content. The data indicate that the exotherm is due to the formation of a crystalline material and not due to a phase transformation.