1103 Simulation for Solidification Microstructure of Pb-free Solder by Phase-Field Method

Laser cladding process inherently includes multi-scale, highly non-linear, and non-equilibrium transport phenomena due to non-uniform and rapid heat flow caused by the laser and the material interaction. Therefore, there is a growing demand to develop systematic modeling and simulation approaches for the multi-scale problem. To address this issue, a process model of solidification microstructure evolution has been studied by utilizing a phase-field method. The phase-field method has become a widely used computational tool for the modeling of solidification microstructure evolution with the advantage of avoiding tracking the interface explicitly and satisfying interfacial boundary conditions. In present work, the numerical solutions of a phase-field model have been analyzed. The linking of macro-scale process and solidification microstructure evolution was examined by considering the relationship of macro- and micro-parameters. The effects of laser power on clad height and surface roughness have also been studied. The predicted results for pure metal dendrite growth were compared with the microsolvability theory and a good agreement was found. Different solidification morphologies of different locations in the melt pool are also investigated. It was found that it is not the mass transfer but the heat transfer in the melt pool that dominates the solidification process.

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Solidification Microstructure Evolution Model for Laser Cladding Process

Journal of Heat Transfer ◽

10.1115/1.2712856 ◽

2006 ◽

Vol 129 (7) ◽

pp. 852-863 ◽

Cited By ~ 8

Author(s):

Y. Cao ◽

J. Choi

Keyword(s):

Heat Flux ◽

Laser Cladding ◽

Microstructure Evolution ◽

Phase Field ◽

Field Method ◽

Solidification Microstructure ◽

Phase Field Method ◽

Structure Evolution ◽

Micro Structure ◽

Laser Cladding Process

The laser cladding process inherently includes multiscale, highly nonlinear, and non-equilibrium transport phenomena due to nonuniform and rapid heat flow caused by the laser and the material interaction. In this work, a process model of solidification micro-structure evolution for the laser cladding process has been studied by utilizing a phase-field method. The phase-field method has become a widely used computational tool for the modeling of solidification micro-structure evolution with the advantage of avoiding tracking the interface explicitly and satisfying interfacial boundary conditions. In the present work, the numerical solutions of a phase-field model have been analyzed. The linking of the macroscale process and solidification microstructure evolution was examined by considering the relationship of macro- and micro-parameters. The effects of melt undercooling and anisotropy on the solidification micro-structure have also been studied. The predicted results with different undercoolings were compared with the microsolvability theory and a good agreement was found. Different solidification morphologies of different locations in the melt-pool are also investigated. To quantitatively study the effect of heat flux on the dendritic growth, the dendrite tip analysis was carried out. It was observed that the dendrite tip that grows in the same direction with the heat flux shows a much higher velocity than a tip that grows in the opposite direction of the heat flux.

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Simulation of Bridgman Directional Solidification Microstructure Using Phase Field Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.652-654.2437 ◽

2013 ◽

Vol 652-654 ◽

pp. 2437-2440

Author(s):

Chunhua Tang ◽

Jin Jun Tang ◽

Cui Liang

Keyword(s):

Grain Boundary ◽

Directional Solidification ◽

Phase Field ◽

Field Method ◽

Planar Interface ◽

Solidification Microstructure ◽

Phase Field Method ◽

Initial Stage ◽

Last Stage ◽

Pulling Velocity

In this paper, the directional solidification microstructure of Bridgman system was simulated using phase-field method, and different calculated results were obtained with four pulling velocities. When the pulling velocity is 0.06 cm/s, the columnar crystals competitively grow in the initial stage, and have a necking phenomenon in the last stage. When the pulling velocity is 0.04 cm/s, the columnar crystals become thinner and competitively grow all the time, and the microsegregation is bigger. When the pulling velocity is 1.00 cm/s, planar interface comes back, and solute trapping takes place. The columnar crystals become much thinner, and microsegregation decreases. When the pulling velocity is 3.00 cm/s, the grain boundary of columnar crystals becomes unconspicuous, and the degree of microsegregation approaches 1.

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