Printed in Great Britain. pergamon Press Ltd. SOLUTION MODELS AND PATTERNS IN ALLOY THERMODYNAMICS

Abstract- The thermodynamics of binary and dilute ternary alloys are discussed in terms of the electron theory of metals and the constant pair-wise bonding model. It is shown that both aspects can contribute to our understanding, but the important phenomenon of electron transfer is, at present, poorly understood. This affects the predictive capabilities of these models, but the major development of computerized data banking may not require that significant development be made to what is essentially an experimental body of knowledge. INTRODUCTI ON The development of our quantitative knowledge of the stabilities of metallic solutions has undergone a transformation in the post-war years to a state where the thermodynamics of all of the industrially important metallic elements and a large number of the significant binary systems have been measured at least over a few hundreds of degrees temperature range. From the point of view of the practising metallurgist, the stabilities, ie. Gibbs energies of systems, are all important, and the separation of these into heats and entropies o