Distribution of alloying elements and the corresponding structural evolution of Mn–Sb alloys in high magnetic field gradients

Abstract

The distribution of alloying elements and the corresponding structural evolution of Mn–Sb alloys in magnetic field gradients were investigated in detail. It was found that a high magnetic field gradient could control the distribution of solute element in the alloys during the solidification process and therefore resulted in the coexistence of both primary MnSb and Sb phases or the aggregation of the primary MnSb with a continuous change in morphology. The positions where these primary phases located depended on the direction of field gradient. The control of the solute element distribution by a high magnetic field gradient was realized through the magnetic buoyancy force that could drive the migration of Mn element in the melt, originating from the difference in the magnetic susceptibility between Mn and Sb. The effectiveness of this control depends on the alloy composition, specimen dimension, cooling rate, and |BdB/dz| value.