KINETICS OF MASS EXCHANGE PROCESSES IN TWO-PHASE ZONE.

One of the reasons specifying a process of nonequilibrium solidification of the alloy is its limited nature of mass exchange processes in liquid and solid phases in the region of two-phase state. For deriving a closed-type phenomenological theory predicting compositions and amounts of precipitated phases, geometric structure of the two-phase zone, a degree of diffusion overcooling of intercrystalline liquid volumes and other characteristics of the process, a joint solution of a system of equations in partial derivatives describing heat and diffusion processes in the metal solidified should be considered. An accurate solution of this problem is associated with insurmountable mathematical difficulties and is possible only in a number of individual, perfect cases.