Controlled conditions of heat and mass transfer during crystallization as stimulating factors for improving the properties of metallic materials

Abstract

The emergence of critical conditions in a meta-stable melt is considered under the influence of two main factors: pre-crystallization super-cooling and overcooling rate. The average density of free energy in such conditions is highly inhomogeneous. External impacts are considered as factors controlling the properties of materials. The solidification of the overcooled meta-stable melt is considered in a quasi-chemical approximation, assuming a transition state corresponding to an ideal solution type system. The finite time of existence of the meta-stable state is taken into account. The dimensions of the structural cell are determined by the ratio between the rate of diffusion and heat removal. The obtained estimate of the structure parameter is in qualitative agreement with the experimental dependence.