Competitions correlated with nucleation and growth in non-equilibrium solidification and solid-state transformation

Abstract

Non-equilibrium solidification and solid-state phase transformation, as complicated theoretical fields correlated with thermodynamics and kinetics (e.g. transport and interfacial behaviour), belong to the major topics of physical metallurgy and condensed matter physics. Microscopically, the above non- equilibrium processes consist of nucleation, growth and impingement, which are accompanied with, assisted, and even initiated by several competitive processes. Understanding accurately the compet- itive processes is essential for describing precisely the whole non-equilibrium process. Preparation of advanced materials with improved mechanical and physical-chemical properties can be ascribed to occurrence and development of the competitive processes. So it is timely to describe the competi- tions associated with non-equilibrium solidification and solid-state phase transformation. The prelim- inary review in section I, first, gives a concise historical description for non-equilibrium solidification and solid-state phase transformation, and then, highlights several competitions occurring upon nu- cleation/growth phase transformation. Competitions arising from nucleation thermodynamics and kinetics, competitions of nucleation modes, based on the classical nucleation theory, are described in section II. Competitions of thermal diffusion and solutal diffusion for solidification and competitions of interface-controlled and volume diffusion controlled growth modes for solid-state phase transforma- tion, are described in section III. Section IV summarizes and concludes this review and gives further directions in this fiel