Construction of a pseudo-binary phase diagram for multi-component Ni-base superalloys

A novel method for the representation of multi-component thermodynamics through a pseudo-binary system without any major assumption is presented. Pseudobinary phase diagrams have been constructed for three representative Ni-base superalloys. Expressions for the Gibbs energy of the different phases as a function of the pseudo-binary composition and temperature have been derived. The information derived from the pseudo-binary phase diagrams and Gibbs energy of the various phases represented through pseudo-binary compositions is applied to (a) solidification calculations for determination of dendrite arm spacing using cellular automata model and (b) phase field calculations.