Solute Trapping at a Rapidly Moving Solid/Liquid Interface for a Lennard-Jones Alloy

1989 ◽  
Vol 157 ◽  
Author(s):  
Stephen J. Cook ◽  
Paulette Clancy
Keyword(s):  
Dynamics Simulation ◽  
Segregation Coefficient ◽  
Equilibrium Conditions ◽  
Impurity Atoms ◽  
Lennard Jones ◽  
Interfacial Segregation ◽  
Non Equilibrium Molecular Dynamics ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Substrate Temperatures

ABSTRACTNon-equilibrium Molecular Dynamics simulation methods have been used to study the trapping of “impurities” in an Ag5B15 Lennard-Jones alloy where the B atoms are 10% bigger in diameter than A. The observation of surface melting in this system is used to calculate an equilibrium interfacial segregation coefficient. Simulations of rapid melting and resolidification were performed for the (100) and (111) orientations at two different substrate temperatures (0.65 Tm and 0.95 Tm) for each orientation. Solute impurity atoms are shown to have been trapped at greater concentrations in the solid than under equilibrium conditions. Partitionless solidification is observed when the regrowth velocity greatly exceeds the diffusive velocity.

Non-Equilibrium Molecular Dynamics Simulation of the Rapid Solidification of Metals

1989 ◽  
Vol 159 ◽  
Author(s):  
Cliff F. Richardson ◽  
Paulette Clancy
Keyword(s):  
Molecular Dynamics ◽  
Picosecond Laser ◽  
Simulation Method ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Non Equilibrium Molecular Dynamics ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Non Equilibrium

ABSTRACTThe ultra-rapid melting and subsequent resolidification of Embedded Atom Method models of the fcc metals copper and gold are followed using a Non-Equilibrium Molecular Dynamics computer simulation method. Results for the resolidification of an exposed (100) face of copper at room temperature are in good agreement with recent experiments using a picosecond laser. At T = 0.5 Tm, the morphology of the solid/liquid interface is shown to be similar to a Lennard-Jones model. The morphology of the crystal-vapor interface at 92% of Tm shows a significant disordering of the topmost layers. Difficulties with the EAM model for gold are observed. Comparison of the Baskes et al. and Oh and Johnson embedding functions are discussed.

Velocity and Orientation Dependence of Solute Trapping

1985 ◽  
Vol 57 ◽  
Author(s):  
M. J. Aziz ◽  
J. Y. Tsao ◽  
M. O. Thompson ◽  
P. S. Peercy ◽  
C. W. White
Keyword(s):  
Pulsed Laser ◽  
Orientation Dependence ◽  
Sufficient Accuracy ◽  
Segregation Coefficient ◽  
Solute Trapping ◽  
Impurity Atoms ◽  
Segregation Behavior ◽  
Functional Forms ◽  
Solid Liquid Interface ◽  
Solid Liquid

AbstractThe fraction of impurity atoms in the liquid at the solid-liquid interface that join the crystal, known as the segregation coefficient k, during rapid crystal growth is known to deviate away from the equilibrium value towards unity as the interface speed v increases. Several plausible models have been proposed that account qualitatively for this behavior with different functional forms of k(v). We report measurements of the segregation behavior during rapid solidification following pulsed laser melting of Bi-implanted Si. The velocity dependence and the orientation dependence of the segregation coefficient of Bi in Si has been determined to sufficient accuracy to allow us to distinguish between models. Implications for the mechanism of solute trapping are discussed.

scholarly journals Molecular dynamics simulation of the solid-liquid interface migration in terbium

2018 ◽  
Vol 148 (21) ◽  
pp. 214705 ◽  
Author(s):  
M. I. Mendelev ◽  
F. Zhang ◽  
H. Song ◽  
Y. Sun ◽  
C. Z. Wang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Liquid Interface ◽  
Dynamics Simulation ◽  
Interface Migration ◽  
Solid Liquid Interface ◽  
Solid Liquid

scholarly journals The In-Plane Structure and Dynamic Property of the Homogeneous Al-Al Solid-Liquid Interface

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 602 ◽  
Author(s):  
Rui Yan ◽  
Sida Ma ◽  
Tao Jing ◽  
Hongbiao Dong
Keyword(s):  
Strong Dependence ◽  
Diffusion Constant ◽  
Dynamics Simulation ◽  
Bulk Liquid ◽  
Density Maps ◽  
Structure Factors ◽  
Out Of Plane ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
And Diffusion

Using molecular dynamics simulation and a newly developed COMB3 potential, the in-plane ordering and diffusion constant profiles at the homogeneous (100), (110), and (111) interfaces between solid and liquid Al have been examined. We found that the in-plane ordering characterized by 2-D density maps and 2-D structure factors existed in the first 6, 10, and 3 out-of-plane layers at the (100), (110), and (111) interfaces, respectively, showing a strong dependence on substrate orientation. In layers with in-plane ordering, the diffusion constant is greatly reduced relative to its value in the bulk liquid, while the influence of layers without in-plane ordering is negligible. The three diffusivity components turn out to be isotropic at the homogeneous interfaces. The Al-Al interfaces studied here will serve as an important reference in comparisons of the structure and properties of different solid-liquid interfaces, which will greatly support the design of grain refiners.

Solidification and Epitaxial Re-Growth in Surface Nanostructuring With Laser-Assisted Scanning Tunneling Microscope

2005 ◽  
Author(s):  
Xinwei Wang ◽  
Yongfeng Lu
Keyword(s):  
Thermal Strain ◽  
Interface Velocity ◽  
Liquid Interface ◽  
Dynamics Simulation ◽  
Scanning Tunneling ◽  
Shear Stresses ◽  
Surface Nanostructuring ◽  
Long Time ◽  
Solid Liquid Interface ◽  
Solid Liquid

In this work, parallel molecular dynamics simulation is conducted to study the long-time (up to 2 ns) behavior of argon crystal in surface-nanostructuring with laser-assisted STM. A large system consisting of more than one hundred million atoms is explored. The study is focused on the solidification procedure after laser irradiation, which is driven by heat conduction in the material. Epitaxial re-growth is observed in the solidification. Atomic dislocation due to thermal strain-induced structural damages is observed as well in the epitaxial re-growth. During solidification, the liquid is featured with decaying normal compressive stresses and negligible shear stresses. Two functions are designed to capture the structure and distinguish the solid and liquid regions. These functions work well in terms of reflecting the crystallinity of the material and identifying the atomic dislocations. The study of the movement of the solid-liquid interface reveals an accelerating velocity in the order of 3~5 m/s. The spatial distribution of the solid-liquid interface velocity indicates a non-uniform epitaxial re-growth in space. The bottom of the liquid solidifies slower than that at the edge.

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