Chapter 2 History of CALPHAD

• Published in: Pergamon Materials Series Vol. 1; pp. 7 - 29
• Format: Book Chapter
• Language: English
• Published: Elsevier Science & Technology 1998
• ISBN: 9780080421292; 0080421296
• ISSN: 1470-1804
• DOI: 10.1016/S1470-1804(98)80022-9

This chapter discusses the history of CALculation of PHAse Diagram (CALPHAD). The history of CALPHAD is a chronology of what can be achieved in the field of phase equilibria, by combining basic thermodynamic principles, with mathematical formulations, to describe the various thermodynamic properties of the phases. The roots of the CALPHAD approach lie with van Laar (1908), who applied Gibbs energy concepts to phase equilibria at the turn of the century. However, he did not have the necessary numerical input to convert his algebraic expressions into phase diagrams that referred to real systems. The 1970s and 1980s proved to be the time when CALPHAD established itself as an accepted tool in the general armory of materials modeling. While, by necessity, it retained a level of empiricism, there was a continuous attempt throughout this period to provide a more physical basis for the modeling process. The number of people involved in CALPHAD methods was also increasing appreciably and new researchers were to profoundly influence the subject area as a whole. The present state-of-art of CALPHAD is at a high level and it is a very varied and powerful approach to solving problems, associated with thermochemistry and phase equilibria.