Driving forces for interface kinetics and phase field models

AbstractPhase field models for applications in physics and materials science are typically written in variational form starting from a free energy functional, and sharp interface descriptions for moving boundary problems can be formulated similarly. Here we discuss why and under which circumstances this postulate for deriving the equations of motion is justified, and what are limitations for specific cases. We investigate this in particular for alloys, systems with elastic, viscoelastic and plastic effects, mainly based on analytical and numerical investigations in one dimension. We find that the naturally guessed equations of motion, as derived via partial functional derivatives from a free energy, are usually reasonable, only for materials with plastic effects this assumption is more delicate due to the presence of internal variables

Elastic and plastic effects on solid-state transformations: A phase field study

We discuss a model of diffusion limited growth in solid-state transformations, which are strongly influenced by elastic effects. Density differences and structural transformations provoke stresses at interfaces, which affect the phase equilibrium conditions. We study the growth of a stable phase from a metastable solid in a channel geometry, and perform phase field simulations. Extensions to plastic models are discussed