Phenomenological Calculations of Phase-Equilibria: the Calphad Approach

Abstract

Although the acronym CALPHAD clearly relates to the calculation of phase diagrams, the activity loosely called “The Calphad Approach” has always involved coupling the calculation of phase diagrams with other forms of thermochemical input (Kaufman, 1977), which is therefore the corner-stone of this approach. The second most basic feature is the capability of calculating multi-component systems, with no particular limit on the number or nature of the components. In order to be industrially useful, it is necessary to achieve a high level of accuracy with respect to critical temperatures and compositions. This is achieved by using interactive feed-back from trial compositions and heat-treatments suggested from initial calculations.