Phase-field simulation of forced flow effect on random preferred
growth direction of multiple grains
growth direction of multiple grains
(1. State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials,
Lanzhou University of Technology, Lanzhou 730050, China;
2. Computer Aided Designed Center, Lanzhou University of Technology, Lanzhou 730050, China;
3. Research Center of Gansu Non-ferrous Metal Materials and
Composite Materials Engineering, Lanzhou 730050, China)
Lanzhou University of Technology, Lanzhou 730050, China;
2. Computer Aided Designed Center, Lanzhou University of Technology, Lanzhou 730050, China;
3. Research Center of Gansu Non-ferrous Metal Materials and
Composite Materials Engineering, Lanzhou 730050, China)
Abstract: The random distribution problem of dendrite preferred growth direction was settled by random grid method. This method was used to study the influence of forced laminar flow effect on multiple grains during solidification. Taking high pure succinonitrile (SCN) undercooled melt as an example, the forced laminar flow effect on multiple grains was studied by phase-field model of single grain which coupled with flow equations at non-isothermal condition. The simulation results show that the random grid method can reasonably settle the problem of random distribution and is more effective. When the solid fraction is relatively low, melt particles flow around the downstream side of dendrite, and the flow velocity between two dendrite arms becomes high. At the stage of solidification time less than 1800Δt, every dendrite grows freely; the upstream dendrites are stronger than the downstream ones. The higher the melt flow rate, the higher the solid fraction. However, when the solid fraction is relatively high, the dendrite arm intertwins and only a little residual melt which is not encapsulated can flow; the solid fraction will gradually tend to equal to solid fraction of melt without flow.
Key words: phase-field method; multiple grains; laminar flow; preferred growth direction; computer simulation; solidification; flow velocity