Siberian Federal University

This paper presents equations for calculating the activity and activity coefficients during the crystallization of melts using the example of the Al-Si system, which can be used to calculate the liquidus line of the phase diagram. A brief review of mathematical modeling of “composition-property” diagrams for metal alloy systems is presented on the example of a double system “aluminum-silicon”. The main attention is paid to the construction of a mathematical model to describe the dependences of various properties of the alloy on the composition, in particular, temperature, activity and activity coefficient. The results obtained in a systematic study of a number of binary systems with the participation of metals are briefly presented. Equations are given for describing the liquidus line of binary metallic systems. Algorithms for finding empirical distribution parameters have been developed, and the physical meaning of these parameters has been indicated