Effects of Forced Electromagnetic Vibrations during the Solidification of Aluminum Alloys: Part II. Solidification in the Presence of Colinear Variable and Stationary Magnetic Fields

摘要

The influence on grain refinement of electromagnetic vibrations imposed during solidification of various aluminum alloys has been examined. The vibrations were produced, without any material contact with the solidifying alloys, by the simultaneous application of a stationary magnetic field B_0 and a periodic magnetic field b(t) of 50 Hz frequency. Extensive grain refinement has been observed in both continuous casting and batch-type mold casting. This investigation shows that the mean grain size obtained by this electromagnetic vibrational method is smaller than that produced by the variable magnetic field acting alone (electromagnetic stirring), particularly when the alloys are characterized by a narrow freezing range.