PREDICTION OF MULTIPHASE EQUILIBRIA IN ALLOY SYSTEMS BY THE TECHNIQUEOF SUCCESSIVE PARTIAL EQUILIBRATION

The technique of successive partial equilibria was recently employed t o predict the precipitation of carbides in equilibrium with a solution phase. This involved predicting the equilibrium between a phase (the solution) whose composition could change with the overall composition of the system, and a phase which had a fixed stoichiometry with respec t to the ratio of the number of atoms in the cationic sub-lattice to t hat in the anionic sub-lattice. This is a special case of predicting p hase equilibria using this technique. In the present communication, th is technique is extended to predict equilibria involving two or more p hases whose compositions can vary over a range, such as that between t wo solutions phases. This technique is illustrated with respect to the Ag-Cu system and some salient features of the algorithm are discussed .