Effects of convection on faceting during directional melt growth processes

A finite element method, based on the boundary conformal mapping technique, was employed in the study of the coupling effects of natural convection and interface kinetics during directional melt growth of single YAG crystals. The influence of convection on thermal distribution, melt/crystal interface shape, and interfacial undercooling of the growth system was investigated. The temperature gradient in the vicinity of the melt/crystal interface becomes large, and the interface shape becomes relatively flat in the presence of strong melt convection. In addition, The corners between the facet region and off-facet region become relatively smooth under convection effect, and correspondingly, the facet size decreases a little compared with the result without melt convection.