The equilibrium of the solid-liquid interface in pressurized solidification process of binary alloys was studied using the Gibbs theory, and the stability of the solid-liquid interface was discussed based on the consideration of the effects of pressure on the diffusion coefficient, the interface growth rate and tile equilibrium liquid composition. A mathematical description of the equi- librium status, the relationship of temperature, pressure, composition and interfacial tension was obtained, and further, a mathematical representation of the curvature radius of solid-liquid interface was developed, which facilitates a thorough understanding of the controlled variables of the interfacial stability.
