Phase Diagrams & Computational Thermodynamics

The NIST Materials Science and Engineering Division and its predecessor, the Metallurgy Division, have long played a major role in the generation, evaluation and use of alloy phase diagrams. Between 1982 and 1990, an international effort to evaluate binary phase diagrams was coordinated by the Metallurgy Division and ASM International. In recent years, our effort has focused on some specific families of alloys, including nickel-based superalloys for aerospace applications and high-temperature and lead-free solders.

A phase diagram is the representation of phase equilibria present in a system as function of the controlling variables, typically composition and temperature.

Computational Thermodynamics is the discipline by which phase diagrams are generated by analysis of the basic thermodynamic properties of the system. Computational thermodynamics enables us to predict some features of the system which are not easily measured, as well as to predict phase diagrams of complex multicomponent systems.

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To learn more about how phase diagrams and computational thermodynamics are used follow these links:

• Read some papers by NIST staff on how phase diagrams are generated and used.
   
• See results of NIST work on solder systems.
   
• Find out more about the Materials Science and Engineering Division and its Thermodynamics and Kinetics Group.
   

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For additional information on phase diagrams and computational thermodynamics follow these links:

• Follow the link to the Ceramics Data to find information on ceramic systems and a glossary of phase equilibria terms.
   
• Follow the link to ASM to find more information on the handbooks on Binary Alloy Phase Diagrams that resulted from the NIST/ASM collaboration.