Equiaxed dendrite growth in alloys at small supercooling

A dimensionless model for growth of equiaxed dendrites in alloys under small Peclet number conditions is presented. The behavior of this model is compared with that of Karma and Langer and to experiments of Chopra. Good agreement between both models and with experiments is found. It is shown that the maximum in growth rate,viz., minimum in tip radius with composition, depends strongly on the ratio of heat-to-solute diffusivity and on the solute distribution coefficient.