scholarly journals Effect of anisotropic surface tension on morphological stability of lamellar eutectic growth in directional solidification

2018 ◽  
Vol 67 (11) ◽  
pp. 118103
Author(s):  
Xu Xiao-Hua ◽  
Chen Ming-Wen ◽  
Wang Zi-Dong
Keyword(s):  
Surface Tension ◽  
Directional Solidification ◽  
Eutectic Growth ◽  
Morphological Stability ◽  
Lamellar Eutectic ◽  
Anisotropic Surface

THE EFFECT OF ANISOTROPIC SURFACE TENSION ON THE LAMELLAR EUTECTIC GROWTH IN DIRECTIONAL SOLIDIFICATION

2019 ◽  
Vol 26 (07) ◽  
pp. 1850216
Author(s):  
XIAOHUA XU ◽  
MINGWEN CHEN
Keyword(s):  
Surface Tension ◽  
Directional Solidification ◽  
Triple Point ◽  
Eutectic Growth ◽  
Solute Diffusion ◽  
Interface Temperature ◽  
Lamellar Eutectic ◽  
Anisotropic Effect ◽  
Anisotropic Surface ◽  
Effect Of Surface

For the case of small interlamellar spacing relative to the solute diffusion length, the steady spatially periodic lamellar eutectic growth with the anisotropic effect of surface tension in directional solidification is studied by the approach of the interfacial wave (IFW) theory. The anisotropic surface tension is expressed as the fourfold symmetric function. We obtained a family of the uniformly valid asymptotic solutions for the steady lamellar eutectic growth and determined the corresponding interfacial patterns affected by anisotropic surface tension. The analytical solution reveals the anisotropic effect of surface tension on the interface shape of lamellar eutectic growth near the triple point. The temperature distribution at the interface shows a noticeable nonuniformity and there is a thin boundary layer for temperature and concentration near the triple point. As the anisotropic surface tension increases, the interface temperature away from the triple-point increases, whereas near the triple point the interface temperature decreases. Compared with the lamellar eutectic growth with isotropic surface tension, the anisotropic surface tension changes the position of the triple point and accelerates the growth of the lamellar eutectic. The theoretical prediction shows quantitatively consistent with recent experimental data without making any artificial adjustments to parameters.

Stability and selection of lamellar eutectic growth with anisotropic surface tension

2018 ◽  
Vol 32 (21) ◽  
pp. 1850245
Author(s):  
Xiaohua Xu ◽  
Mingwen Chen
Keyword(s):  
Surface Tension ◽  
Eutectic Growth ◽  
Critical Number ◽  
Instability Mechanism ◽  
Wave Instability ◽  
Lamellar Eutectic ◽  
Anisotropic Surface ◽  
Number Formula ◽  
The Stability ◽  
Exchange Of Stability

The morphological stability of lamellar eutectic growth with the anisotropic effect of surface tension is studied by means of the interfacial wave (IFW) theory developed by Xu in the 1990s. We solve the related linear eigenvalue problem for the case that the Peclet number is small and the segregation coefficient parameter is close to the unit. The stability criterion of lamellar eutectic growth with the anisotropic surface tension is obtained. The linear stability analysis reveals that the stability of lamellar eutectic growth depends on a stability critical number [Formula: see text]. Similar to the case of isotropic surface tension, the system involves two types of global instability mechanisms: the “exchange of stability” invoked by the non-oscillatory, unstable modes and the “global wave instabilities” invoked by four types of oscillatory unstable modes, namely antisymmetric–antisymmetric (AA-), symmetric–symmetric (SS-), antisymmetric–symmetric (AS-) and symmetric–antisymmetric (SA-) modes. The anisotropic surface tension, by decreasing the corresponding stability critical number [Formula: see text], stabilizes the “exchange of stability” mechanism and “global wave instability” mechanism invoked by AA-, SA- and SS-modes. However, by increasing the corresponding stability critical number [Formula: see text], the anisotropic surface tension destabilizes the “global wave instability” mechanism invoked by AS-mode.

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

EFFECT OF ANISOTROPIC SURFACE TENSION ON THE MORPHOLOGICAL STABILITY OF DEEP CELLULAR CRYSTAL GROWTH IN DIRECTIONAL SOLIDIFICATION

2019 ◽  
Vol 26 (06) ◽  
pp. 1850210
Author(s):  
HAN JIANG ◽  
MING-WEN CHEN ◽  
ZI-DONG WANG
Keyword(s):  
Surface Tension ◽  
Crystal Growth ◽  
Directional Solidification ◽  
Low Frequency ◽  
Expansion Method ◽  
Frequency Instability ◽  
Morphological Stability ◽  
Global Instability ◽  
Anisotropic Surface ◽  
Low Frequency Instability

This paper studies the effect of anisotropic surface tension on the morphological stability of deep cellular crystal in directional solidification by using the matched asymptotic expansion method and multiple variable expansion method. We find that the morphological stability of deep cellular crystal growth with anisotropic surface tension shows the same mechanism as that with isotropic surface tension. The deep cellular crystal growth contains two types of global instability mechanisms: the global oscillatory instability, whose neutral modes yield strong oscillatory dendritic structures, and the low-frequency instability, whose neutral modes yield weakly oscillatory cellular structures. Anisotropic surface tension has the significant effect on the two global instability mechanisms. As the anisotropic surface tension increases, the unstable domain of global oscillatory instability decreases, whereas the unstable domain of the global low-frequency instability increases.

scholarly journals Effect of anisotropic surface tension on deep cellular crystal growth in directional solidification

2014 ◽  
Vol 63 (3) ◽  
pp. 038101
Author(s):  
Chen Ming-Wen ◽  
Chen Yi-Chen ◽  
Zhang Wen-Long ◽  
Liu Xiu-Min ◽  
Wang Zi-Dong
Keyword(s):  
Surface Tension ◽  
Crystal Growth ◽  
Directional Solidification ◽  
Anisotropic Surface

scholarly journals Locked-lamellar eutectic growth in thin Al-Al2Cu samples: in situ directional solidification and crystal orientation analysis

2021 ◽  
pp. 126203
Author(s):  
Sabine Bottin-Rousseau ◽  
Mehdi Medjkoune ◽  
Oriane Senninger ◽  
Laurent Carroz ◽  
Richard Soucek ◽  
...  
Keyword(s):  
Directional Solidification ◽  
Crystal Orientation ◽  
Eutectic Growth ◽  
Orientation Analysis ◽  
Lamellar Eutectic

The Effect of Anisotropic Surface Tension on Directional Solidification in the Extremely Short Wave Region

2011 ◽  
Vol 365 ◽  
pp. 130-134
Author(s):  
Ming Wen Chen ◽  
Xin Feng Wang ◽  
Yan Lin Wang ◽  
Zi Dong Wang
Keyword(s):  
Surface Tension ◽  
Expansion Method ◽  
Short Wave ◽  
Planar Interface ◽  
Morphological Stability ◽  
Tension Parameter ◽  
Anisotropic Surface ◽  
Wave Region ◽  
Short Wave Region ◽  
Perturbation Growth

The morphologicalstability of a planar interface with the inclusion of the anisotropic surface tension is studied. The dispersion relation is obtained by means of the multi-variable expansion method. The result shows that the morphological stability of the solidification system in the extremely short wave region depends on the undercooling. As the anisotropic surface tension parameter increases the perturbation growth rate of the interface increases and the solidification system in the extremely short-wave region tends to destabilize.

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