Effects of Spiral Magnetic Field Intensity on the Solidification Structure of Pb-80Sn Hypereutectic Alloy

Effects of magnetic field and intensity of electromagnetic stirring on solidification structure and macro-composition segregation of Pb-80 Sn cast ingots were investigated.The results show that spiral magnetic field has a better effect in improving the solidification structure and macro composition segregation through promoting a large zone stirring for alloy melt to make the solute and temperature field distribution more uniform.At a fixed frequency,the solidification structure exhibits desirable when the current is 125 Afor rotating magnetic field and 100 Afor spiral magnetic field,where the grain sizes are reduced to 152.6μm and 143.2μm from 247.5μm without magnetic field,respectively.The composition segregation is relieved greatly when the current is 125 Afor both rotating and spiral magnetic field,reduced to 1.37%and 0.28%from 9.71%in the absence of magnetic field,respectively.