Models describing the interaction of particles with a plane solid/liquid interface

Various models depicting particle engulfment or rejection in contact with a plane organic solidification front have been examined and their predictions compared with the experimental results for six particle/matrix systems. The directionally solidified composites were made of different kinds of particles such as nylon, teflon or polystyrene dispersed within biphenyl or naphthalene matrices. The thermodynamic and thermal approaches achieve a good agreement with the experimental results for low solidification rate and particle volume fraction. In order to make the particle engulfment or rejection modelling more complete, a kinetic approach has been developed considering a critical interface velocity above which particles are engulfed and below which particles are pushed. Unfortunately, the related model did not allow the behaviour of particles in front of a plane solid/liquid interface to be successfully predicted.