稳态磁场下合金凝固过程微观偏析行为研究进展

Research Progress of Microsegregation Behavior During Alloy Solidification under Steady Magnetic Field

磁场通过改变合金凝固过程中的过冷度、固态扩散、枝晶粗化、熔体对流及枝晶生长形态等因素影响铸件微观偏析的形成,改变铸件的力学性能。本文评述了磁场下微观偏析研究进展,分析了在磁场作用下影响微观偏析形成的主要因素的变化规律,总结了磁场下合金凝固过程形核与枝晶生长、溶质分配行为变化规律,讨论了磁场下合金凝固过程中微观偏析的形成机理。在经典微观偏析模型的基础上,构建了磁场下微观偏析模型,预测磁场下微观偏析变化趋势,为磁控偏析技术的应用奠定理论基础。

The magnetic field affects the formation of microsegregation by changing factors such as undercooling,solid-state diffusion, dendrite coarsening, melt convection and dendrite growth during alloy solidification, which leads to changing the mechanical properties of castings. In this paper, the research progress of microsegregation under magnetic field is reviewed, and the modifications of the main factors affecting the formation of microsegregation under the action of magnetic field is analyzed. The changes in nucleation, dendritic growth and solute distribution under the magnetic field are summarized. Formation mechanism of microsegregation during solidification under the magnetic field is discussed. On the basis of the classical microsegregation model, a microsegregation model under magnetic field is constructed to predict the variation trend of microsegregation under magnetic field, which lays a theoretical foundation for the application of magnetic field to control solute segregation.