Numerical simulation of dendritic grain growing during Al-Cu alloy solidification

A dendrite grain growth model that is based on cellular automaton method was developed and applied to simulate the columnar dendrite grain growth during the directional solidification process of Al-Cu binary alloys.And the velocity model was based upon the solute conservation at the solid/liquid interface.The influences of different cooling speeds and different nucleation conditions on the dendrite morphologies and solute segregation were considered.The results indicate that the solute of high concentration liquids is easy to concentrate in the closed or semi-enclosed zones among secondary or tertiary dendrite arms.The grain boundary segregation becomes more severe when the cooling speed is increased.At the same time,the nucleation density affects the dendrite morphologies,especially the growth of secondary and tertiary dendrite arms.