EFFECT OF PARAMETERS ON DENDRITIC PATTERNS AND MICROSEGREGATION OF Ni-Cu BINARY ALLOY
会议名称：《第五届国际材料与热加工物理模拟及数值模拟学术会议》
会议日期：2007年
学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）]
基 金：This work was supported by the Natural Science Foundation of Gansu Province Open Foundation of State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials
关 键 词：Phase-field model Dendritic patterns Microsegregation Numerical simulation
摘 要：The effects of various material parameters such as solid diffusivity Ds, anisotropy parameterε , interface kinetic coefficient β and surface energy σ on dendritic patterns and microsegregation is investigated by using a phase-field model which couples concentration gradient for two-dimensional simulation of binary alloy solidification. The computed results indicate that, different material parameters lead to different dendritic patterns and severity of microsegregation. The smaller Ds is, as well as the larger ε, β, σ are, the greater the dendritic tip velocity is, the more developed the side-branches are. The larger Ds is, the less drastically the solid’s solute composition undulates, and the extent of microsegregation minishes;ε affects the dendritic tip’s steady state, the larger εis, the more drastically the solid solute composition’s undulation is, and the severity of microsegregation ahead of solid/liquid interface aggravates;the larger β is, the more acutely the solid solute composition’s fluctuates, but the severity of microsegregation ahead of solid/liquid interface reduces;On increasing σ , the fluctuant extent of the solid’s solute composition reduces correspondingly, and an increased level of σ alleviates the severity of microsegregation ahead of solid/liquid interface.