The Effects of Electromagnetic Stirring on Solidification Structure and Macrosegregation of Pb-Sn Alloy

Abstract

The effects of different electromagnetic field and technological parameters on the microstructure and composition segregation of Pb-80%Sn alloy were studied. The results show that, both rotating and spiral magnetic field can improve the composition segregation ,refine grains of alloy. Moreover,the spiral magnetic field is more effective on improving composition homogenization and grain refining. The electromagnetic force distribution of spiral magnetic field is more helpful to form a well stirring in a larger zone and promote the formation of equiaxed grains, and the direction of the grain arrangement is much smaller. The technical parameters of spiral magnetic field have been optimized. It is found that, under the spiral magnetic field condition, when stirring time and exciting current exceeded a critical value, the size of the primary phase became larger. Therefore, there existed an optimum value of magnetic stirring parameters for the homogenization of component and refinement of grains.