Effect of initial morphology on particle growth in an undercooled melt

Abstract

The effect of initial morphology on particle growth in an undercooled melt is studied in terms of an analytical approach. The growth of the particle is formulated as a dynamics model for the particle with different initial morphologies of concave and convex deformations. By using the asymptotic method, we solve the asymptotic solution of the dynamics model of the particle. The asymptotic solution reveals the effect of convexity and concavity of the initial shapes of the non-spherical particle on the temperature, concentration, and growth rate of the particle in an undercooled melt. The interface temperature in the concave part of the interface becomes higher than that in the convex part. The solutes are enriched near the concave part of the interface more than near the convex part of the interface. Compared with the convex part of the interface, the local undercooling and solute enrichment in the concave part of the interface facilitate the particle growth. The convexity of the particle depresses the particle growth, and the concavity of the particle promotes the particle growth. As the particle grows, the effect of initial morphology of non-spherical particles on particle growth attenuates, and the non-spherical particle tends to evolve into a spherical particle.