二元合金非等温凝固相场法模拟

利用耦合温度场与溶质场的相场模型对Al-Cu二元合金非等温凝固时枝晶生长过程进行了模拟。研究了人为变化的不同热扩散系数对枝晶生长行为的影响。计算结果表明：随着热扩散系数的减小，潜热释放对熔体内原有温度场的影响也减小，熔体内过冷度能够更好地保持；而枝晶尖端生长速度将增大．枝晶呈现出更发达的侧向分支；同时，溶质偏析程度也越小。将计算模拟结果和实验结果进行了比较，两者吻合良好。

Phase-Field Simulation of Non-Isothermal Dendritic Growth of Binary Alloy

A phase-field approach which incorporates both heat and solute equations for simulation of Al-Cu binary alloy solidification is studied. The dependence of dendritic growth behavior on intentionally varied thermal diffusivity Dris investigated. The calculated results indicate that with the decrease of the thermal diffusivity DT, the influence of the release of latent heat on the original temperature field decreases, the undercoolins in The melt can maintain relatively steady; while the dendritic lip velocity increases, the dendritic morphology presents more developed side-branches, and the solute segregation is small accordingly. The simulation results are compared with those obtained experimentally; they agree well with each other.