Interaction of convection and solidification at fluid-solid-interfaces

Phase change from the liquid to the solid state is of crucial importance for many natural and technical processes, such as lava flow, casting and welding of metallic materials, crystal growth from semiconductor melts. A phase transition “liquid to solid” can initiate convection by the release of latent heat, density changes during solidification, segregation and concentration of solute at the phase change interface. Convection in the liquid phase induced by temperature and/or concentration gradients can lead to feed back effects, which may modify significantly the thermal and solutal environment at the interface and thereby determine the local solidification process. The interaction of convection and solidification is demonstrated by three striking examples; Bénard convection, directional solidification, gravity driven spreading flows.