Two-dimensional phase-field simulations of dendrite competitive growth during the directional solidification of a binary alloy bicrystal

2014 ◽  
Vol 81 ◽  
pp. 272-283 ◽  
Author(s):  
Tomohiro Takaki ◽  
Munekazu Ohno ◽  
Takashi Shimokawabe ◽  
Takayuki Aoki
China Foundry ◽  
2018 ◽  
Vol 15 (5) ◽  
pp. 333-342 ◽  
Author(s):  
Li Feng ◽  
Ya-long Gao ◽  
Ni-ni Lu ◽  
Chang-sheng Zhu ◽  
Guo-sheng An ◽  
...  

2016 ◽  
Vol 442 ◽  
pp. 14-24 ◽  
Author(s):  
Tomohiro Takaki ◽  
Munekazu Ohno ◽  
Yasushi Shibuta ◽  
Shinji Sakane ◽  
Takashi Shimokawabe ◽  
...  

2013 ◽  
Vol 842 ◽  
pp. 57-60 ◽  
Author(s):  
Yan Bo Dong ◽  
Ming Chen ◽  
Xi Wang

The competitive growth of multiple dendrites and crystal growth of directional solidification in a Mg-Al binary alloy were simulated using phase-field model, and the effect of undercooling value on the microstructural dendritic growth pattern in directional solidification process was studied in the paper. The simulation results showed the impingement of the adjacent grains, which made the dendrite growth inhibited in the competitive growth of multiple dendrites, and in directional solidification process, quantitative comparison of different undercooling values that predicted the columnar dendrite evolution were carried out. With the increasing of the undercooling value, the dendrite tip radius and second dendrite arms became smaller, and the crystal structure is more uniform and dense.


2013 ◽  
Vol 774-776 ◽  
pp. 703-706
Author(s):  
Ming Chen ◽  
Yu Jiang ◽  
Wen Long Sun ◽  
Xiao Dong Hu ◽  
Chun Li Liu

Phase field method (PFM) offers the prospect of carrying out realistic numerical calculation on dendrite growth in metallic systems. The dendritic growth process of multiple dendrites and direcitonal solidification during isothermal solidifications in a Fe-0.5mole%C binary alloy were simulated using phase field model. Competitive growth of multiple equiaxed dendrites were simulated, and the effect of anisotropy on the solute segregation and microstructural dedritic growth pattern in directional solidification process was studied in the paper. The simulation results showed the impingement of arbitrarily oriented grains, and the grains began to impinge and coalesce the adjacent grains with time going on, which made the dendrite growth inhibited obviously. In the directional solidification, the maximum concentration gradient showed in the dendrite tip, and highest solute concentration existed at the bottom of the dendrites. With the increasing of the anisotropy, dendrite tip radius became smaller, and the crystal structure is more uniform and dense.


1999 ◽  
Vol 395 ◽  
pp. 253-270 ◽  
Author(s):  
Y.-J. CHEN ◽  
S. H. DAVIS

A steady, two-dimensional cellular convection modifies the morphological instability of a binary alloy that undergoes directional solidification. When the convection wavelength is far longer than that of the morphological cells, the behaviour of the moving front is described by a slow, spatial–temporal dynamics obtained through a multiple-scale analysis. The resulting system has a parametric-excitation structure in space, with complex parameters characterizing the interactions between flow, solute diffusion, and rejection. The convection in general stabilizes two-dimensional disturbances, but destabilizes three-dimensional disturbances. When the flow is weak, the morphological instability is incommensurate with the flow wavelength, but as the flow gets stronger, the instability becomes quantized and forced to fit into the flow box. At large flow strength the instability is localized, confined in narrow envelopes. In this case the solutions are discrete eigenstates in an unbounded space. Their stability boundaries and asymptotics are obtained by a WKB analysis. The weakly nonlinear interaction is delivered through the Lyapunov–Schmidt method.


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