Directional growth of monotectic alloy with and without shear flow

Abstract

The directional growth process of para-dichlorobenzene and succinonitrile (DCB-SCN) monotectic alloy is realized under static condition and in presence of shear flow. The experimental results show that, with the increase of pulling rate, the DCB phase exhibits faceted growth while the monotectic structure undergoes a transition in which "separated liquid and solid phases-aligned fibrous composite structure-droplet dispersion in solid matrix" take place. When shear flow is applied, perturbation and fluctuation appear at each growing crystal plane. In the meantime, the fibrous spacing is larger compared with those under the same pulling rate without flow. However, the spacing and pulling rate also follow the relationship λV0.5=C. In the formation process of droplet dispersion structure, shear flow enhances the nucleation rate of second liquid drops and hinder the growth and interaction of second liquid droplets at the solid-liquid interface, leading to the refinement of the final droplet dispersion structure.