Investigation on the effect of lamellar thickness on three-dimensional lamellar eutectic growth by multi-phase field model

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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PHASE-FIELD MODELING OF ELASTIC EFFECTS IN EUTECTIC GROWTH WITH MISFIT STRESSES

International Journal of Modeling Simulation and Scientific Computing ◽

10.1142/s1793962312500249 ◽

2012 ◽

Vol 04 (01) ◽

pp. 1250024

Author(s):

ZOHREH EBRAHIMI ◽

JOAO REZENDEH

Keyword(s):

Phase Field ◽

Elastic Energy ◽

Field Model ◽

Phase Field Model ◽

Solidification Process ◽

Eutectic Growth ◽

Point Of View ◽

Eutectic Solidification ◽

Elastic Model ◽

Sharp Interface Model

Elastic interactions, arising from a difference of lattice spacing between two coherent phases in eutectic alloys with misfit stresses, can have an influence on microstructural pattern formation of eutectic colonies during solidification process. From a thermodynamic point of view the elastic energy contributes to the free energy of the phases and modifies their mutual stability. Therefore, the elastic stresses will have an effect on stability of lamellae, lamellae spacing and growth modes. In this paper, a phase-field model is employed to investigate the influence of elastic misfits in eutectic growth. The model reduces to the traditional sharp-interface model in a thin-interface limit, where the microscopic interface width is small but finite. An elastic model is designed, based on linear microelasticity theory, to incorporate the elastic energy in the phase-field model. Theoretical and numerical approaches, required to model elastic effects, are formulated and the stress distributions in eutectic solidification structures are evaluated. The two-dimensional simulations are performed for directed eutectic growth and the simulation results for different values of the misfit stresses are illustrated.

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Phase-Field Simulation of Three-Dimensional Dendritic Growth

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.97-101.3769 ◽

2010 ◽

Vol 97-101 ◽

pp. 3769-3772 ◽

Cited By ~ 1

Author(s):

Chang Sheng Zhu ◽

Jun Wei Wang

Keyword(s):

Computational Methods ◽

Phase Field ◽

Interfacial Energy ◽

Dendritic Growth ◽

Field Model ◽

Three Dimensional ◽

Phase Field Model ◽

Computational Time ◽

Field Simulation ◽

Undercooled Melt

Based on a thin interface limit 3D phase-field model by coupled the anisotropy of interfacial energy and self-designed AADCR to improve on the computational methods for solving phase-field, 3D dendritic growth in pure undercooled melt is implemented successfully. The simulation authentically recreated the 3D dendritic morphological fromation, and receives the dendritic growth rule being consistent with crystallization mechanism. An example indicates that AADCR can decreased 70% computational time compared with not using algorithms for a 3D domain of size 300×300×300 grids, at the same time, the accelerated algorithms’ computed precision is higher and the redundancy is small, therefore, the accelerated method is really an effective method.

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