The role of intense convective flow on dendrites evolving with n-fold symmetry

Convection plays an essential role in the growth of dendrites. It may influence the transport of heat and substances as well as mechanical deformation of dendritic crystals. In this paper, the effect of convective heat and mass transport that substantially changes the dendrite tip diameter and its tip velocity is demonstrated. Using currently developed models for dendrite growth with flow and the selection theory in the case of n-fold crystal symmetry, we present the results of commutations and quantitatively compare them with experimental data. Namely, we give the critical analysis of experimental data for solidifying T i 45 A l 55 samples processed in electromagnetic levitators on the Ground and in microgravity conditions. The theory is tested against experimental data for both tip velocity and tip diameter. It is shown that convection plays an essential role in formation of habitus of crystals, morphological stability and growth kinetics of crystal interfaces.