Phase equilibria in the LiF-AlF₃Na₃AlF₆ system

The phase equilibria relationships in the Na₃AlF₆-AlF₃-LiF ternary system have been investigated using a combination of quenching, optical microscopy, DTA, and x-ray powder diffraction techniques. The compatibility relations at 500°C, the binary system Na₃AlF₆-Li₃AlF₆, and the ternary liquidus surface were determined. The liquidus surface was found to contain the following five important invariant points: 1) eutectic - 81% LiF, 9.5% Na₃AlF₆, 9.5% AlF₃ and 685°C 2) eutectic - 56% LiF, 6% Na₃AlF₆, 38% AlF₃ and 585°C 3) eutectic - 37% LiF, 17% Na₃AlF₆, 46% AlF₃ and 620°C 4) peritectic - 30% LiF, 37% Na₃AlF₆, 33% AlF₃ and 660°C 5) reaction point - 65% LiF, 9% Na₃AlF₆, 26% AlF₃ and 675°C The 500°C isothermal section contains 7 three-phase regions and 2 large two-phase regions. The binary system Na₃AlF₆-Li₃AlF₆ contained 2 incongruently melting compounds, many polymorphic transformations, and a eutectic at 690°C and 67 mole % Li₃AlF₆.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Ceramic Engineering

Department dc:contributor.department

Ceramic Engineering

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1974

Author dc:creator

• Stinton, David Paul

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/64717

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/64717