Liquid concentration distribution and planar interface instability at an abruptly changing pulling velocity in directional solidification

2007 ◽  
Vol 50 (1) ◽  
pp. 118-126 ◽  
Author(s):  
ShuangMing Li ◽  
HengZhi Fu
Keyword(s):  
Directional Solidification ◽  
Concentration Distribution ◽  
Planar Interface ◽  
Interface Instability ◽  
Liquid Concentration ◽  
Pulling Velocity

Simulation of Bridgman Directional Solidification Microstructure Using Phase Field Method

2013 ◽  
Vol 652-654 ◽  
pp. 2437-2440
Author(s):  
Chunhua Tang ◽  
Jin Jun Tang ◽  
Cui Liang
Keyword(s):  
Grain Boundary ◽  
Directional Solidification ◽  
Phase Field ◽  
Field Method ◽  
Planar Interface ◽  
Solidification Microstructure ◽  
Phase Field Method ◽  
Initial Stage ◽  
Last Stage ◽  
Pulling Velocity

In this paper, the directional solidification microstructure of Bridgman system was simulated using phase-field method, and different calculated results were obtained with four pulling velocities. When the pulling velocity is 0.06 cm/s, the columnar crystals competitively grow in the initial stage, and have a necking phenomenon in the last stage. When the pulling velocity is 0.04 cm/s, the columnar crystals become thinner and competitively grow all the time, and the microsegregation is bigger. When the pulling velocity is 1.00 cm/s, planar interface comes back, and solute trapping takes place. The columnar crystals become much thinner, and microsegregation decreases. When the pulling velocity is 3.00 cm/s, the grain boundary of columnar crystals becomes unconspicuous, and the degree of microsegregation approaches 1.

scholarly journals Effect of crystallographic orientation on instability behavior of planar interface in directional solidification

2012 ◽  
Vol 61 (14) ◽  
pp. 148104
Author(s):  
Wang Li-Lin ◽  
Wang Xian-Bin ◽  
Wang Hong-Yan ◽  
Lin Xin ◽  
Huang Wei-Dong
Keyword(s):  
Directional Solidification ◽  
Crystallographic Orientation ◽  
Planar Interface

The effect of anisotropic surface tension on the morphological stability of planar interface during directional solidification

2009 ◽  
Vol 18 (4) ◽  
pp. 1691-1699 ◽  
Author(s):  
Chen Ming-Wen ◽  
Lan Man ◽  
Yuan Lin ◽  
Wang Yu-Yan ◽  
Wang Zi-Dong ◽  
...  
Keyword(s):  
Surface Tension ◽  
Directional Solidification ◽  
Planar Interface ◽  
Morphological Stability ◽  
Anisotropic Surface

Phase-Field Simulation of Directional Solidification Microstructure Evolution in a Binary Alloy

2011 ◽  
Vol 399-401 ◽  
pp. 1862-1865
Author(s):  
Jin Jun Tang ◽  
Jian Zhong Jiang ◽  
Chun Hua Tang ◽  
Da Hui Chen ◽  
Xiu Rong Zhu ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Directional Solidification ◽  
Microstructure Evolution ◽  
Phase Field ◽  
Initial Temperature ◽  
Planar Interface ◽  
Space Length ◽  
Velocity Increase ◽  
Field Simulation ◽  
Solute Boundary Layer

In order to obtain the directional microstructure of different supersaturation and growing velocity, three simulations is calculated with different initial temperature. When the initial temperature is 1576K, and the supersaturation and growing velocity are smaller. The average space length of columnar crystals is bigger, and the directional microstructure grows by the wide columnar crystals. Microsegregation is smaller; when the initial temperature is 1574K, the supersaturation and growing velocity increase. when the initial temperature falls to 1566K, the planar interface comes back, and microsegregation decreases rapidly. The directional microstructure grows by the thinnest columnar crystals. At the same time, the transverse solute profiles and solute boundary layer are also talked in this paper.

scholarly journals Numerical Analysis of Phosphorus Concentration Distribution in a Silicon Crystal during Directional Solidification Process

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 27
Author(s):  
Satoshi Nakano ◽  
Xin Liu ◽  
Xue-Feng Han ◽  
Koichi Kakimoto
Keyword(s):  
Numerical Analysis ◽  
Directional Solidification ◽  
Concentration Distribution ◽  
Silicon Crystal ◽  
Vertical Direction ◽  
Solidification Process ◽  
Phosphorus Concentration ◽  
Directional Solidification Process ◽  
P Type ◽  
Evaporation Flux

For bulk doping, boron and phosphorus are usually used as p-type and n-type dopants, respectively. The distribution of these dopant concentrations in a silicon crystal along the vertical direction is governed by the segregation phenomena. As the segregation coefficient of phosphorus is small, phosphorus concentration distribution in a silicon crystal becomes inhomogeneous; inhomogeneous phosphorus concentration distribution affects the distribution of resistivity in the crystal. Therefore, it is important to control the phosphorus concentration distribution in a silicon crystal and make it uniform. In this study, by numerical analysis, we investigated the effect of the evaporation flux at the melt surface on phosphorus concentration distribution during the directional solidification process. To obtain a homogeneous phosphorus concentration distribution in the silicon crystal, we had to control the phosphorous evaporation flux at the melt surface and maintain approximately the same phosphorus concentration in the melt during the entire solidification process even though the growth rate was always changing.

Tilted Dendritic Growth Dynamics and Dendrite to Degenerate Seaweed Transition in Directional Solidification: Insights from Phase-Field Simulations

2018 ◽  
Vol 15 ◽  
pp. 128-153
Author(s):  
Hui Xing ◽  
Xiang Lei Dong ◽  
Jian Yuan Wang ◽  
Ke Xin Jin
Keyword(s):  
Directional Solidification ◽  
Misorientation Angle ◽  
Phase Field ◽  
Dendritic Growth ◽  
Growth Dynamics ◽  
Growth Direction ◽  
Primary Spacing ◽  
Stability Range ◽  
Spacing Selection ◽  
Pulling Velocity

In this paper, we review our results from phase field simulations of tilted dendritic growth dynamics and dendrite to seaweed transition in directional solidification of a dilute alloy. We focus on growth direction selection, stability range and primary spacing selection, and degenerate seaweed-to-tilted dendrite transition in directional solidification of non-axially orientated crystals. For growth direction selection, the DGP law (Phys. Rev. E, 78 (2008) 011605) was modified through take the anisotropic strength and pulling velocity into account. We confirm that the DGP law is only validated in lower pulling velocity. For the stability range and primary spacing selection, we found that the lower limit of primary spacing is irrelative to the misorientation angle but the upper limit is nonlinear with respect to the misorientation angle. Moreover, predicted results confirm that the power law relationship with the orientation correction by Gandin et al. (Metall. Mater. Trans. A. 27A (1996) 2727-2739) should be a universal scaling law for primary spacing selection. For the seaweed-to-dendrite transition, we found that the tip-splitting instability in degenerate seaweed growth dynamics is related to the M-S instability dynamics, and this transition originates from the compromise in competition between two dominant mechanisms, i.e., the macroscopic thermal field and the microscopic interfacial energy anisotropy.

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