Glossary of Terms for Phase Equilibria Diagrams

A B C D E G H I J L M P S T V

Solid Solution
Solidus
Subsystem
System

  • Solid Solution
    A single crystalline phase which may be varied in composition within finite limits without the appearance of an additional phase.

    Reference: Levin, E.M., McMurdie, H.F., and Hall, F.P., Phase Diagrams for Ceramists: Volume 1, The American Ceramic Society, Columbus, Ohio, p. 8, 1956.

    Example of Solid Solution

    Example of Solid Solution



  • Solidus
    The locus of temperature-composition points in a system at temperatures above which solid and liquid are in equilibrium and below which the system is completely solid. In binary diagrams without solid solutions, it is a straight line, representing constant temperature, and with solid solutions, it is a curved line or combination of curved and straight lines. Likewise, in ternary systems, the solidus is represented by a flat plane or curved surface, respectively.

    Reference: Levin, E.M., McMurdie, H.F., and Hall, F.P., Phase Diagrams for Ceramists: Volume 1, The American Ceramic Society, Columbus, Ohio, p. 8, 1956.

    Example of Solidus

    Example of Solidus



  • Subsystem
    Any portion of a binary, ternary, etc. system which can be treated as an independent binary or ternary, etc. system. The selected substances designating the subsystem must be components for the subsystem.

    Reference: Levin, E.M., McMurdie, H.F., and Hall, F.P., Phase Diagrams for Ceramists: Volume 1, The American Ceramic Society, Columbus, Ohio, p. 8, 1956.



  • System
    A system is that part of the universe that is chosen for study. The rest of the universe is then called the surroundings. The choice of what to include in the system is completely free, and is made to suit the purposes at hand.

    Reference: Levin, E.M., McMurdie, H.F., and Hall, F.P., Phase Diagrams for Ceramists: Volume 1, The American Ceramic Society, Columbus, Ohio, p. 8, 1956.






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