The influence of Prandtl numbers of melts and crucible materials on the features of crystal growth by the Bridgman method

Abstract

The processes of crystallization of silicon and heptadecan in flat-bottomed cylindrical crucibles in conjugate convective heat transfer regime were studied numerically by the finite element method. Crystallization of silicon was investigated in a graphite crucible. Crystallization of heptadecane was investigated in a Plexiglas crucible. The possibility of existence of two convective vortices over a solidification front during the crystallization of silicon and heptadecane has been discovered. Crystallization of heptadecane was studied at two rates of lowering the crucible into the cold zone. Lowering of the crucible was simulated by moving the breakpoint in the temperature distribution on the outer side of the crucible walls. The breakpoint was the boundary of transition from the wall area heated to the initial temperature to the area with a given temperature gradient. Adaptive grids on triangles tracking the position of the crystallization front at each time step were used. The software package of developed by the authors was used.