Phase equilibria in the LiF-AlF₃-Na₃AlF₆-Al₂O₃ system

The phase equilibria relationships in the Li₃A1F₆-A1₂0₃ binary system, the Li₃A1F₆-Na₃AlF₆-A1₂0₃ ternary system and the LiF-A1F₃-Na₃A1F₆-Al₂0₃ quaternary system have been investigated using a combination of X-ray powder diffraction, DTA, quenching and optical microscopy techniques. The compatibility relations at 500°C for the ternary and quaternary systems, the Li₃A1F₆-A1₂0₃ binary system and the ternary liquidus surface were determined. The binary system was found to have a eutectic at 754°C and 1 mole % Al₂0₃. The liquidus surface was found to contain the following three invariant points: 1. eutectic - 66 mole % Li₃A1F₆, 29% Na₃A1F₆, 5% A1₂0₃ and 670°C 2. peritectic - 51 mole % Li₃A1F₆, 42.5% Na₃A1F₆, 65% A1₂0₃ and 683°C 3. reaction point - 65 mole % Li₃A1F₆, 33% Na₃A1F₆, 2% A1₂0₃ and 693°C. The 500°C isothermal section contains three 3-phase regions and one 2-phase region. The quaternary system contains 7 compatibility tetrahedra at 500°C.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Materials Engineering

Department dc:contributor.department

Materials Engineering

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1977

Author dc:creator

• Cassidy, Roger Thomas

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/10919/64131

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/64131