Phase field modeling of dendritic coarsening during isothermal

Dendritic coarsening in Al-2mol%Si alloy during isothermal solidification at 880K was investigated by phase field modeling.Three coarsening Hair Accessories mechanisms operate in the alloy: (a) melting of small dendrite arms; (b) coalescence of dendrites near the tips leading to the entrapment of liquid droplets; (c) smoothing of dendrites.Dendrite melting is found to be dominant in the stage of dendritic growth, whereas coalescence of dendrites and smoothing of Arm Slings dendrites are dominant during isothermal holding.The simulated results provide a better understanding of dendrite coarsening during isothermal solidification.