Structure and kinetics of three-dimensional defects on the {101¯2} twin boundary in magnesium: Atomistic and phase-field simulations

AbstractThe coarsening kinetics of γ’ precipitates in binary and ternary Al3Sc1-xZrx alloys is studied by using the two- and three-dimensional phase-field simulations. Our focus is on the influence of diffusion coefficients of Sc and Zr atoms on the transformation path kinetics from disordered f.c.c. matrix to two phases equilibrium state with γ’ precipitates and f.c.c. disordered matrix. Our simulation results demonstrate that in the case of binary alloys taking into account the concentration dependence of the mobility of atoms decreases the coarsening rate. In the case of ternary alloys we show that the Al3Sc particles precipitate first following by appearance of a Zr-rich shell. Our simulations results are in good agreement with experimental observations.

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On the kinetics of dendritic sidebranching: A three dimensional phase field study

Journal of Applied Physics ◽

10.1063/1.4947450 ◽

2016 ◽

Vol 119 (16) ◽

pp. 164305 ◽

Cited By ~ 7

Author(s):

Shan Shang ◽

Zhipeng Guo ◽

Zhiqiang Han

Keyword(s):

Field Study ◽

Phase Field ◽

Three Dimensional ◽

Kinetics Of

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Three-dimensional phase field simulation of the morphology and growth kinetics of Ni4Ti3precipitates in a NiTi alloy

Modelling and Simulation in Materials Science and Engineering ◽

10.1088/0965-0393/22/5/055018 ◽

2014 ◽

Vol 22 (5) ◽

pp. 055018 ◽

Cited By ~ 6

Author(s):

C B Ke ◽

S Cao ◽

X P Zhang

Keyword(s):

Growth Kinetics ◽

Phase Field ◽

Niti Alloy ◽

Three Dimensional ◽

Phase Field Simulation ◽

Field Simulation ◽

Kinetics Of

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Dendrite fragmentation: an experiment-driven simulation

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2017.0213 ◽

2018 ◽

Vol 376 (2113) ◽

pp. 20170213 ◽

Cited By ~ 8

Author(s):

T. Cool ◽

P. W. Voorhees

Keyword(s):

Phase Field ◽

Contact Region ◽

Three Dimensional ◽

Dendritic Structure ◽

Phase Field Model ◽

Alloy System ◽

Growth Conditions ◽

Dendrite Fragmentation ◽

Kinetics Of ◽

Small Spacing

The processes leading to the fragmentation of secondary dendrite arms are studied using a three-dimensional Sn dendritic structure that was measured experimentally as an initial condition in a phase-field simulation. The phase-field model replicates the kinetics of the coarsening process seen experimentally. Consistent with the experiment, the simulations of the Sn-rich dendrite show that secondary dendrite arm coalescence is prevalent and that fragmentation is not. The lack of fragmentation is due to the non-axisymmetric morphology and comparatively small spacing of the dendrite arms. A model for the coalescence process is proposed, and, consistent with the model, the radius of the contact region following coalescence increases as t 1/3 . We find that small changes in the width and spacing of the dendrite arms can lead to a very different fragmentation-dominated coarsening process. Thus, the alloy system and growth conditions of the dendrite can have a major impact on the fragmentation process. This article is part of the theme issue ‘From atomistic interfaces to dendritic patterns’.

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Three-dimensional phase-field simulations of coarsening kinetics of γ′ particles in binary Ni–Al alloys

Acta Materialia ◽

10.1016/j.actamat.2004.02.032 ◽

2004 ◽

Vol 52 (9) ◽

pp. 2837-2845 ◽

Cited By ~ 144

Author(s):

J.Z. Zhu ◽

T. Wang ◽

A.J. Ardell ◽

S.H. Zhou ◽

Z.K. Liu ◽

...

Keyword(s):

Phase Field ◽

Three Dimensional ◽

Al Alloys ◽

Coarsening Kinetics ◽

Kinetics Of

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THREE DIMENSIONAL MULTI--PHASE FIELD SIMULATION OF GROWTH OF EUTECTIC CBr4--C2Cl6 ALLOY I. Modeling and Testing

ACTA METALLURGICA SINICA ◽

10.3724/sp.j.1037.2010.00781 ◽

2010 ◽

Vol 46 (7) ◽

pp. 781-786 ◽

Cited By ~ 3

Author(s):

Yujuan YANG ◽

Biao YAN

Keyword(s):

Phase Field ◽

Three Dimensional ◽

Phase Field Simulation ◽

Field Simulation ◽

Multi Phase

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A Novel Pseudomonas geniculata AGE Family Epimerase/Isomerase and Its Application in d-Mannose Synthesis

Foods ◽

10.3390/foods9121809 ◽

2020 ◽

Vol 9 (12) ◽

pp. 1809

Author(s):

Zhanzhi Liu ◽

Ying Li ◽

Jing Wu ◽

Sheng Chen

Keyword(s):

3D Structure ◽

Three Dimensional ◽

Optimal Temperature ◽

Reaction Conditions ◽

Enzymatic Production ◽

Physiological Properties ◽

Potential Applications ◽

Kinetics Of ◽

Optimal Reaction ◽

Gene Age

d-mannose has exhibited excellent physiological properties in the food, pharmaceutical, and feed industries. Therefore, emerging attention has been applied to enzymatic production of d-mannose due to its advantage over chemical synthesis. The gene age of N-acetyl-d-glucosamine 2-epimerase family epimerase/isomerase (AGEase) derived from Pseudomonas geniculata was amplified, and the recombinant P. geniculata AGEase was characterized. The optimal temperature and pH of P. geniculata AGEase were 60 °C and 7.5, respectively. The Km, kcat, and kcat/Km of P. geniculata AGEase for d-mannose were 49.2 ± 8.5 mM, 476.3 ± 4.0 s−1, and 9.7 ± 0.5 s−1·mM−1, respectively. The recombinant P. geniculata AGEase was classified into the YihS enzyme subfamily in the AGE enzyme family by analyzing its substrate specificity and active center of the three-dimensional (3D) structure. Further studies on the kinetics of different substrates showed that the P. geniculata AGEase belongs to the d-mannose isomerase of the YihS enzyme. The P. geniculata AGEase catalyzed the synthesis of d-mannose with d-fructose as a substrate, and the conversion rate was as high as 39.3% with the d-mannose yield of 78.6 g·L−1 under optimal reaction conditions of 200 g·L−1d-fructose and 2.5 U·mL−1P. geniculata AGEase. This novel P. geniculata AGEase has potential applications in the industrial production of d-mannose.

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Phase-field modeling of grain evolutions in additive manufacturing from nucleation, growth, to coarsening

npj Computational Materials ◽

10.1038/s41524-021-00524-6 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Min Yang ◽

Lu Wang ◽

Wentao Yan

Keyword(s):

Additive Manufacturing ◽

Phase Field ◽

Field Model ◽

Three Dimensional ◽

Phase Field Model ◽

Nucleation Theory ◽

Experimental Result ◽

Classical Nucleation Theory ◽

Validation Experiment ◽

Powder Particles

AbstractA three-dimensional phase-field model is developed to simulate grain evolutions during powder-bed-fusion (PBF) additive manufacturing, while the physically-informed temperature profile is implemented from a thermal-fluid flow model. The phase-field model incorporates a nucleation model based on classical nucleation theory, as well as the initial grain structures of powder particles and substrate. The grain evolutions during the three-layer three-track PBF process are comprehensively reproduced, including grain nucleation and growth in molten pools, epitaxial growth from powder particles, substrate and previous tracks, grain re-melting and re-growth in overlapping zones, and grain coarsening in heat-affected zones. A validation experiment has been carried out, showing that the simulation results are consistent with the experimental results in the molten pool and grain morphologies. Furthermore, the grain refinement by adding nanoparticles is preliminarily reproduced and compared against the experimental result in literature.

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