电磁复合场制备匀质Zn-Bi偏晶合金的物理模拟

摘要

Through physical simulation, we study the influence mechanism of electromagnetic field on the solidification structure of homogeneous Zn-Bi monotectic alloy, the transformation rule of the diameter of molten secondary phase under the compound field, and the process of the shattering of the layered structure into matrix by the Lorentz force. The results show that the diameter of the secondary drop decreases with AC current density and magnetic field increasing. The influence of AC frequency has an optimal value from which the deviation can weaken the suppression of diameter, which accords with the experimental result. The layered metal liquid can be uniformly mixed under the action of electromagnetio field. The above effects can effectively release segregation of the second phase of monoteetic alloy. The simulation results show the main factors of preparing the homogeneous monotectic alloy in an electromagnetic field intuitively.%本文通过物理模拟的方法研究了强磁场复合交变电流作用对过偏晶合金凝固组织的影响机理，考察了电磁复合场下第二相初生液滴直径的演变规律，以及洛伦兹力作用下已分层少数相被“打碎”进入基体相的过程．结果表明：电磁体积力的增加，有利于液滴初始直径的减小；而交变电流频率的影响存在最佳值，偏离该值对初生液滴直径的抑制效果下降，这与实际试验规律一致；在电磁复合场作用下，已经分层的两液相可以重新实现均匀混合．这些效应有效缓解了偏晶合金凝固前第二相由于各种因素导致的偏聚，模拟结果直观地揭示了电磁复合场制备匀质偏晶合金的主要机理