Phase-field simulation of dendritic growth in a forced liquid metal flow coupling with boundary heat flux

A phase-field model with forced liquid metal flow was employed to study the effect of boundary heat flux on the dendritic structure forming of a Ni-40.8%Cu alloy with liquid flow during solidification. The effect of the flow field coupling with boundary heat extractions on the morphology change and distributions of concentration and temperature fields was analyzed and discussed. The forced liquid flow could significantly affect the dendrite morphology, concentration and temperature distributions in the solidifying microstructure. And coupling with boundary heat extraction, the solute segregation and concentration diffusion were changed with different heat flux. The morphology, concentration and temperature distributions were significantly influenced by increasing the heat extraction, which could relatively make the effect of liquid flow constrained. With increasing the initial velocity of liquid flow, the lopsided rate of the primary dendrite arm was enlarged and the transition of developing manner of the secondary arms moved to the large heat extraction direction. It was the competition between heat flux and forced liquid flow that finally determined microstructure forming during solidification.