GROWTH-BEHAVIOR OF NH4CL-H2O MIXTURES

A discontinuity in the growth velocity, as a function of undercooling, was reported for tin alloys by Nikonova and Temkin and also for boron doped nickel by Eckler et al. A similar discontinuity in the growth r ate as a function of undercooling of ammonium-chloride-water solutions is reported. While the dendritic growth behavior of several alloys ha s been successfully modeled, the observed discontinuity in the growth rate of ammonium chloride crystals cannot be fit using the same equati ons. Since the samples used in this work have large concentrations of the second component, water, the observed discontinuity is attributed to some other mechanism.