THE INFLUENCE OF FOREIGN PARTICLES IN THE FORMATION OF POLYCRYSTALLINE SOLIDIFICATION PATTERNS

摘要

Crystallization of real materials is often influenced by impurities unintentionally introduced into the melt, although the influence of such heterogeneities has received relatively limited consideration in the scientific literature devoted to the modeling of crystal growth. Recent observations on clay-polymer blend films indicate that particulate additives, in addition to serving as nucleating agents, may also perturb crystal growth, leading to the formation of irregular dendritic morphologies. Here we examine the formation of these "dizzy dendrites" using a phase field theory in which randomly distributed foreign particle inclusions perturb the crystallization by deflecting the tips of the growing dendrite arms. We include a complete description of the equations solved, as well as a slight correction to our previous treatment of this problem.