中文摘要：

纯 Mg 的团结的微观结构上的一个搏动的磁场的效果被调查。纯 Mg 的微观结构更加在搏动的磁场和平均谷物尺寸下面经由 columnar-to-equiaxed 生长被精制的结果表演在最佳的处理条件下面被精制到 260 m。一个数学模型被造用 ANSYS 软件在团结期间描述电磁流动的地的相互作用。搏动的电的电路首先被解决然后它被代替进磁场模型。液体流动模型与获得的电磁的力量被解决。当前的波浪上并且在分发上的脉搏电压频率的效果磁性并且流动领域数字地被学习。搏动的磁场增加融化传送对流，它搅动并且断裂树枝状的手臂进片。这些破片被液体流动和行为作为原子核搬运进体积液体提高谷物精炼。电流生产的焦耳热效果也参予微结构精炼。

英文摘要：

The effects of a pulsed magnetic field on the solidified microstructure of pure Mg were investigated.The results show that microstructure of pure Mg is considerably refined via columnar-to-equiaxed growth under the pulsed magnetic field and the average grain size is refined to 260？？ under the optimal processing conditions.A mathematical model was built to describe the interaction of the electromagnetic-flow fields during solidification with ANSYS software.The pulsed electric circuit was first solved and then it is substituted into the magnetic field model.The fluid flow model was solved with the acquired electromagnetic force.The effects of pulse voltage frequency on the current wave and on the distribution of magnetic and flow fields were numerically studied.The pulsed magnetic field increases melt convection,which stirs and fractures the dendritic arms into pieces.These broken pieces are transported into the bulk liquid by the liquid flow and act as nuclei to enhance grain refinement.The Joule heat effect produced by the electric current also participates in the microstructural refinement.