Nonequilibrium Interface Dynamics:
Theory and Simulation from Atomistic to Continuum Scales

CSIC Building (#406), Seminar Room 4122.
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Phase Field Modeling of Solidification: An Introduction

Dr. James Warren

Center for Theoretical and Computational Materials Science (CTCMS), NIST

Abstract:   The classical picture of a liquid solid interface represents this boundary as a mathematically two-dimensional surface separating the two phases. In order to model solidification one needs to model transport of energy and matter (typically by diffusion equations) in each of the bulk phases, and also the dynamics of the liquid-solid interface. Since this interface's shape and velocity are an unknown part of the mathematical problem (and can take shapes as complicated as a snowflake), modeling solidification can be quite a challenging numerical exercise. Over the last decade, a new method, called the phase field method, has become popular. This method finesses the problem of tracking the interface by the introduction of a continuous order parameter, the phase field. The introduction of the phase field results in a description of the liquid-solid interface which now has a finite width, and thus is referred to as a diffuse interface description, and the classical description is now referred to as sharp interface description. A derivation of the phase field approach, and it's application to pure and alloy systems will be developed.