Abstract
A phase field model is used to study dendritic growth in a media with
impurities. The model consists of a square lattice where a parameter can
take values between 0 and 1 at each site. A site is in the solid phase for Psi > 1, in the liquid phase for Psi = 0, and the solid-liquid
interface is expressed by 0 < Psi < 1. A fraction of the sites are
considered impurities that cannot be solidified, i.e. Psi is fixed and
taken as zero. These impurities are distributed randomly. As the
probability p of impure sites in the lattice increases, the growth loses
its dendritic characteristic. It is shown that the perimeter of the
growing solid goes from quadratic to a linear function with time. It was also found that as the probability of impurities reaches p = 0.004, the
solid undergoes a transition from anisotropic to isotropic growth.
Users
Please
log in to take part in the discussion (add own reviews or comments).