scholarly journals A Phase-Field Study of Microstructure Evolution in Tungsten Polycrystalline under He/D Irradiation

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7433
Author(s):  
You-Sung Han
Keyword(s):  
Fractal Dimension ◽  
Phase Field ◽  
Field Model ◽  
Empirical Relation ◽  
Phase Field Model ◽  
Current Phase ◽  
Dimension Analysis ◽  
Irradiation Energy ◽  
Fractal Dimension Analysis ◽  
Growth Of Voids

Analyses in the present study focus on understanding the evolution of the tungsten microstructure under He/D irradiation. A fractal dimension analysis was utilized to characterize the structural pattern of the microstructure irradiated by both low (10–80 eV) and high (8–30 keV) irradiation energy. All examined W microstructures show a direct correlation between the fractal dimension and irradiation energy. Analyses establish an empirical relation expressing a change in the microstructure as a function of the irradiation energy based on the changes in the fractal dimension of the microstructures. The proposed relation was implemented in the phase-field model formulation with an account of the interfacial energy induced by the crystallographic mismatch between grains under irradiation. The current phase-field model captures the evolution of the void under irradiation, including nucleation and the growth of voids, and sink efficiency for vacancy annihilation in the vicinity of grain boundaries.

A Phase-Field Model for Rapid Solidification with Non-Equilibrium Solute Diffusion

2015 ◽  
Vol 817 ◽  
pp. 14-20
Author(s):  
Hai Feng Wang ◽  
Cun Lai ◽  
Xiao Zhang ◽  
Kuang Wang ◽  
Feng Liu
Keyword(s):  
Rapid Solidification ◽  
Phase Field ◽  
Growth Velocity ◽  
Field Model ◽  
Phase Field Model ◽  
Solute Diffusion ◽  
Current Phase ◽  
Diffusion Velocity ◽  
Good Agreement ◽  
Non Equilibrium

Since the growth velocity can be comparable with or even larger than the solute diffusion velocity in the bulk phases, modeling of rapid solidification with non-equilibrium solute diffusion becomes quite an important topic. In this paper, an effective mobility approach was proposed to derive the current phase field model (PFM). In contrast with the previous PFMs that were derived by the so-called kinetic energy approach, diffusionless solidification happens not only in the bulk phases but also inside the interface when the growth velocity is equal to the solute diffusion velocity in liquid. A good agreement between the model predictions and experimental results is obtained for rapid solidification of Si-9at.%As alloy.

MARMOT Phase-Field Model for the U-Si System

2016 ◽  
Author(s):  
Larry Kenneth Aagesen ◽  
Daniel Schwen
Keyword(s):  
Phase Field ◽  
Field Model ◽  
Phase Field Model

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

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.

A two-scale iterative scheme for a phase-field model for precipitation and dissolution in porous media

2021 ◽  
Vol 396 ◽  
pp. 125933
Author(s):  
Manuela Bastidas Olivares ◽  
Carina Bringedal ◽  
Iuliu Sorin Pop
Keyword(s):  
Porous Media ◽  
Phase Field ◽  
Field Model ◽  
Iterative Scheme ◽  
Phase Field Model
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