Analysis of the Factors Affecting the Interface Deflection in the Vertical Bridgman Configuration

Abstract

A transient finite‐element numerical simulation of the heat transfer and melt convection has been performed for the vertical Bridgman growth configuration in order to investigate the solid‐liquid interface deflection. The numerical simulation is realized with the help of the finite element software FIDAPTM. A free surface model is applied for the description of the moving solid‐liquid interface. By a dimensional analysis of the factors which affect the interface deflection, the influence of the nondimensional ratio δ = VIH/(kLGL) on the interface curvature is studied. The dimensionless interface curvatures are computed for different values of the interface rate VI, the latent heat of fusion H, the liquid thermal gradient GL and the thermal conductivity of liquid kL. Finally a simple expression which contains the quantity δ is proposed for the interface deflection.

Numerical modeling of radiative heat transfer in Bridgman solidification of semi-transparent BaF2 crystals

“…1b). This significant effect of the latent heat can be explained by considering previous analytical calculations [14], which show that the influence of the latent heat on interface deflection depends on the dimensionless quantity:…”

Growth of concentrated GaInSb alloys with improved chemical homogeneity at low and variable pulling rates

“…The value of the thermal interface deflection computed from relations proposed in Refs. [13,14] is f T % 1:4 mm. Because the interface was not visualized in the Ga 0.85 In 0.15 Sb experiment, the experimental data for the interface deflection are missing in Fig.…”

“…In order to simplify Eq. (14), the approximation 1 À K ffi 1 can be used for the low segregation coefficients. In this case, the solution of Eq.…”

Control of growth interface shape using vibroconvective stirring applied to vertical Bridgman growth

“…The macroscopic crystal-melt interface shape is important in directional solidification processes because it strongly influences the generation and propagation of defects during growth as well as the radial compositional uniformity of the crystal [1][2][3][4][5][6][7][8][9][10][11][12][13]. Defects tend to propagate normal to the growth interface, so that defects will tend to grow into crystals with interfaces concave with respect to the melt and out of crystals with convex interfaces.…”

“…A number of factors have been shown to influence the crystal-melt interface shape including the thermal conductivities of the melt, crystal, and crucible, the axial and radial furnace gradients, the growth rate, and the convection in the melt [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Although each of these factors is important, melt convection is the main topic of this paper.…”