Kinetic phase diagram for a binary system near the transition to diffusionless solidification

TL;DR

This paper develops an analytical kinetic phase diagram for binary systems near diffusionless solidification, considering local nonequilibrium effects and interface velocity modes, revealing a possible temperature maximum at high velocities.

Contribution

It introduces a new analytical expression for the temperature-velocity response function without relying on equilibrium phase diagrams, accounting for drag effects at high interface velocities.

Findings

Identification of a local interface temperature maximum at V = V_D due to drag effects.

Analytical derivation of the kinetic phase diagram in the nonequilibrium regime.

Analysis of interface movement modes with and without drag effects.

Abstract

The rapid solidification of a binary mixture in the region of the interface velocities $V$ close to the diffusion speed in the bulk of the liquid phase $V_D$ is considered within the framework of the local nonequilibrium approach. In this high-speed region the derivation of the analytical expression for the response function "temperature-velocity" representing kinetic phase diagram is given without using the concept of the equilibrium phase diagram. The modes of movement of the interface both without and with the drag effect are analyzed. It is shown that the drag effect can be accompanied by a local interface temperature maximum at $V = V_D$.