The reversible inward growth of a particle in an alloy melt induced by anisotropic interface kinetics

The growth of particles in the alloy melt with anisotropic interface kinetics is studied in terms of the asymptotic method. The resulting asymptotic solution for the dynamics model of the particle shows that because of the anisotropic effect of interface kinetics the particle undergoes the reversible inward growth in the early stage of crystal growth along some growth directions. In the early stage of crystal growth, the particle first grows inward along some growth directions, while it grows outward along other growth directions. When the inward growth along these growth directions attains a certain depth, the particle starts to grow outward with the interface along other growth directions. The locally reversible inward growth induced by anisotropic interface kinetics results in the petal-like morphological pattern of the particle in the early stage of crystal growth. The petal-like morphology of the particle may favor grain refinement of microstructures when it is exerted to some perturbations during solidification of alloy melts.