Kinetics at Early Stages of Phase Transformations in Metallic Alloys

Abstract

Problems of the theoretical description of nonequilibrium statistical systems are important for various areas of physics. For equilibrium systems, such a description is given by the Gibbs distribution and statistical thermodynamics, but for states far from equilibrium there are no analogous standard approaches available. The elaboration of suitable approaches is of particular interest for configurational alloy kinetics, the evolution of the atomic distribution in nonequilibrium alloys. The microstructure and macroscopic properties of such alloys, e.g. strength and plasticity, depend crucially on their thermal and mechanical history, for example, on the particular kinetic path of the phase transformation. A number of theoretical approaches have been proposed in that field, e.g.^1–3. However, these approaches either treat the uniform alloy case¹ which excludes from consideration most applications of interest, or use various unclear approximations, such as the extrapolation of the linear Onsager equation for weakly nonequilibrium states to the nonlinear region of states far from equilibrium^2,3, which can result in significant errors^4,5.