Phase-Field Simulation Studies of Dendrite Growth Coupling with Force Flow Field

Abstract

Coupling the force flow field with the phase field model for the isothermal growth of dendrite, Sola algorithm is used to calculate the flow speed and pressure of liquid metal, Using double grid numerical method to reduce the calculation amount of computer simulation, The space factor and time factor are introduced to improve the accuracy of double grid numerical calculation, Taking Al-2%-Cu alloy as an example, the dendrite growth process of the binary alloy under forced convection environment is simulated; The simulation results can capture the real dendrite growth and interactions of the liquid metal flow in the process of dendrite growth under forced convection environment: In the incident flow regions, the dendrite morphology is complex, the secondary dendrite is lush and the growth speed is fast due to the influence of liquid metal flow. In the back flow regions, the growth of dendrite changes the flowing pressure among the liquid metals, it causes the regional complex flow patterns and there are two opposite eddy current; the grow speed of the main branch which grows perpendicular to the initial flow direction is the fastest and presents tilt growth phenomenon. When the space coefficient value is appropriate, the dual mesh method can save calculation time effectively.

Phase field simulation of multiple phase transformation of Fe-C alloy during solidification process

“…The phase field method has unique advantages in the simulation method of material microstructure [1] .Since there is no need to chase the interface, and it can also eliminate the restriction of long-range diffusion and long-range interaction which cannot be settled by MC method and CA method, the phase field method is rapidly becoming a very important and popular research method. It has been widely used in the field of materials, such as solidification [2] ,grain growth [3] , micro-segregation [4] , solid phase transformation [5][6] , dislocation motion and fracture [7] , Besides, its application range is still expanding. However, the process of phase field simulation is mostly concentrated on the liquid-solid phase transformation or solid-solid phase transformation alone, and the process of the real material solidification process often contains liquid-solid-solid multiple phase transformation, such as Fe-C alloy.…”