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Phase Diagram of a Portion of the System Na 3 AlF 6 ‐AlF 3 ‐Al 2 O 3 .
Author(s) -
FOSTER PERRY A.
Publication year - 1975
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.1151-2916.1975.tb11477.x
Subject(s) - liquidus , cryolite , phase diagram , eutectic system , crystallization , ternary numeral system , crystallography , materials science , mineralogy , analytical chemistry (journal) , powder diffraction , phase (matter) , chemistry , aluminium , metallurgy , microstructure , organic chemistry , chromatography
The system Na 3 AlF 6 ‐AlF 3 ‐Al 2 O 3 was investigated by a combination of quenching, optical microscopy, and X‐ray powder diffraction techniques in order to define liquidus temperatures, univariant lines, and invariant points. Phase fields for the primary crystallization of cryolite, chiolite, aluminum fluoride, α‐alumina, and η‐alumina were located. A ternary peritectic point contained 28.3% AlF 3 ‐4.4% Al 2 O 3 ‐67.3% Na 3 AlF 6 at 723°C. A eutectic point of composition 37.3% AlF 3 ‐3.2% Al 2 O 3 ‐59.5% Na 3 AlF 6 occurs at 684°C.