THE ENGULFMENT OF FOREIGN PARTICLES BY A FREEZING INTERFACE

The interactions of second-phase particles, liquid droplets or gas bub bles with a solidification front form the basis of various materials s ynthesis and purification processes and the design of microstructures in cast metal-matrix composites, as well as frost heaving and biologic al cell interactions. The physical mechanisms of this interaction phen omenon are based upon surface thermodynamic factors, solidification pa rameters, and fluid dynamic effects such as fluid drag and buoyancy. A n overview is presented of the role of various factors which determine the nature as well as the kinetics of foreign particle-solidification front interactions, and the current status and limitations of the var ious theoretical models of the phenomenon.