Numerical simulation of solute segregation patterns for a binary alloy using phase-field approach

The dependence of denderitic patterns and solute segregation on solid diffusivit y D s is studied using a phase-field model which incorporates concentr ation field for Ni-Cu binary alloy dendritic growth. The computed results indica te that with the decrease of solid diffusivity D s , the smaller become s the thickness of the solute diffusion layer ahead of the interface, which is a dvantageous to the growth of the sidebranching, and the more developed the side- branches. The smaller the solid diffusivity D s , the more acutely the solute concentration in solid phase fluctuates. With the increment of solid diff usivity D s , the fluctuations of solute concentration in solid phase a re reduced accordingly. An increased level of solid diffusivity D s re duces the severity of microsegregation.