Nucleation kinetics in supercooled Ni50Ti50: Computer simulation data corroborate the validity of the Classical Nucleation Theory

2019 ◽  
Vol 735 ◽  
pp. 136749 ◽  
Author(s):  
Azat O. Tipeev ◽  
Edgar D. Zanotto
Keyword(s):  
Computer Simulation ◽  
Nucleation Theory ◽  
Classical Nucleation Theory ◽  
Nucleation Kinetics ◽  
Simulation Data ◽  
Computer Simulation Data

scholarly journals Nucleation Behavior of a Single Al-20Si Particle Rapidly Solidified in a Fast Scanning Calorimeter

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2920
Author(s):  
Qin Peng ◽  
Bin Yang ◽  
Benjamin Milkereit ◽  
Dongmei Liu ◽  
Armin Springer ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Rapid Solidification ◽  
Heterogeneous Nucleation ◽  
Nucleation Theory ◽  
Classical Nucleation Theory ◽  
Solidification Behavior ◽  
Nucleation Kinetics ◽  
Nucleation Behavior ◽  
Nucleation Undercooling ◽  
Primary Si

Understanding the rapid solidification behavior characteristics, nucleation undercooling, and nucleation mechanism is important for modifying the microstructures and properties of metal alloys. In order to investigate the rapid solidification behavior in-situ, accurate measurements of nucleation undercooling and cooling rate are required in most rapid solidification processes, e.g., in additive manufacturing (AM). In this study, differential fast scanning calorimetry (DFSC) was applied to investigate the nucleation kinetics in a single micro-sized Al-20Si (mass%) particle under a controlled cooling rate of 5000 K/s. The nucleation rates of primary Si and secondary α-Al phases were calculated by a statistical analysis of 300 identical melting/solidification experiments. Applying a model based on the classical nucleation theory (CNT) together with available thermodynamic data, two different heterogeneous nucleation mechanisms of primary Si and secondary α-Al were proposed, i.e., surface heterogeneous nucleation for primary Si and interface heterogenous nucleation for secondary α-Al. The present study introduces a practical method for a detailed investigation of rapid solidification behavior of metal particles to distinguish surface and interface nucleation.

Ion modes in strongly coupled two-component plasmas

1993 ◽  
Vol 50 (3) ◽  
pp. 359-367 ◽  
Author(s):  
M. A. Berkovsky
Keyword(s):  
Computer Simulation ◽  
Hydrodynamic Model ◽  
Simulation Data ◽  
Frequency Spectra ◽  
Strongly Coupled ◽  
Transverse Modes ◽  
Two Component ◽  
Computer Simulation Data

A generalized hydrodynamic model is used to evaluate the frequency spectra of longitudinal and transverse modes in dense strongly coupled two-component plasmas. The results are compared with available computer simulation data.

Nucleation and Glass Formation

1985 ◽  
Vol 57 ◽  
Author(s):  
D. R. Uhlmann ◽  
M. C. Weinberg
Keyword(s):  
Glass Formation ◽  
Nucleation Theory ◽  
Crystal Nucleation ◽  
Oxide Glass ◽  
Classical Nucleation Theory ◽  
Nucleation Kinetics ◽  
Formation Behavior ◽  
Homogeneous Crystal ◽  
Exponential Factors

AbstractThe role of nucleation kinetics in affecting glass formation behavior is discussed. Also considered are measurements of homogeneous crystal nucleation in a variety of liquids. For a number of oxide glass-forming liquids, available data indicate pre-exponential factors which are larger than those predicted from classical nucleation theory by factors of 1017 to 1049. Possible sources of this discrepancy are discussed.

The Effects of Si on the Nucleation Kinetics of Ferrite in Dual Phase Steels

2007 ◽  
Vol 26-28 ◽  
pp. 1307-1310 ◽  
Author(s):  
Sang Hwan Lee ◽  
Kyung Jong Lee
Keyword(s):  
Free Energy ◽  
Interfacial Energy ◽  
Free Energy Change ◽  
Nucleation Theory ◽  
Energy Change ◽  
Classical Nucleation Theory ◽  
Nucleation Kinetics ◽  
Kinetics Of ◽  
Volume Free Energy Change ◽  
Thermodynamic Factors

It is generally accepted that Si promotes kinetics of polygonal ferrite due to thermodynamic factors such as Ae3 and maximum amount of ferrite formed. However, in this study, it was found that the difference between the measured rates of ferrite formation in C-Mn steel and Si added steel was much larger than that expected considering only thermodynamic factors. The classical nucleation theory with pillbox model was adopted to figure out what is the most controlling factor in formation of ferrite. The volume free energy change was calculated by use of the dilute solution model. The diffusivity of carbon (DC) was formulated as functions of C, Mn and Si by using experimental data. It was found that the volume free energy change was still predominant but the kinetic factors such as interfacial energy and the diffusivity of carbon by addition of Si were not negligible at lower undercooling. However, with increasing undercooling, the diffusivity of C was the most effective on the ferrite kinetics, though the ambiguity of treating interfacial energy was not yet clear.

scholarly journals Microscopic origin of the scattering pre-peak in aqueous propylamine mixtures: X-ray and neutron experiments versus simulations

2019 ◽  
Vol 21 (18) ◽  
pp. 9317-9325 ◽  
Author(s):  
László Almásy ◽  
Alexander I. Kuklin ◽  
Martina Požar ◽  
Anthony Baptista ◽  
Aurélien Perera
Keyword(s):  
Computer Simulation ◽  
Neutron Scattering ◽  
Simulation Data ◽  
X Ray ◽  
Computer Simulation Data ◽  
Microscopic Origin

The structure of aqueous propylamine mixtures is investigated through X-ray and neutron scattering experiments, and the scattered intensities compared with computer simulation data.

The bridge function of hard spheres by direct inversion of computer simulation data

2002 ◽  
Vol 100 (16) ◽  
pp. 2629-2640 ◽  
Author(s):  
JIŘÍ KOLAFA ◽  
STANISLAV LABÍK ◽  
ANATOL MALIJEVSKÝ
Keyword(s):  
Computer Simulation ◽  
Hard Spheres ◽  
Simulation Data ◽  
Bridge Function ◽  
Direct Inversion ◽  
Computer Simulation Data

A study to investigate phase transitions and nucleation kinetics of nickel and copper

2016 ◽  
Vol 30 (11) ◽  
pp. 1650129 ◽  
Author(s):  
F. A. Celik ◽  
A. K. Yildiz
Keyword(s):  
Molecular Dynamics ◽  
Orientational Order ◽  
Nucleation Theory ◽  
Dynamics Simulation ◽  
Classical Nucleation Theory ◽  
Structural Development ◽  
Nucleation Kinetics ◽  
Embedded Atom ◽  
Bond Orientational Order ◽  
Kinetics Of

In this study, we investigate the homogeneous nucleation kinetics of copper and nickel system during cooling process using molecular dynamics simulation (MDS). The calculation is carried out for a different number of atoms consisting of 500, 2048, 8788 and 13,500 based on embedded atom method (EAM). It is observed that the melting points for the both model increases with increasing the size of systems (i.e. the number of atoms) as expected from Parrinello and Rahman MD method. The interfacial free energies and critical nucleus radius of nickel and copper are also determined by molecular dynamics, and the results are consistent with the classical nucleation theory. The structural development and phase transformation are also determined from the radial distribution function (RDF) and local bond orientational order parameters (LBOO).

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