Microscopic Mechanisms of Solute Migration and Redistribution at the Solid-Liquid Interface During Directional Solidification of a Cu–Ag Eutectic Alloy Under High Magnetic Fields

High magnetic field-assisted solidification holds immense promise in manipulating the microstructures and properties of metallic materials. However, solute migration and redistribution at the solid-liquid interface during such solidification are not thoroughly understood at a microscopic level. To elucidate the mechanisms involved, directional solidification and quench experiments were performed with Cu–Ag eutectic alloys under various magnetic fields and solidification rates. The results showed that a high magnetic field intensified the solute enrichment of the liquid phase in front of the two eutectic phases simultaneously but to different extents. By calculating the solute partition coefficients, increased solute segregation can be confirmed under a high magnetic field. The changes in solute migration and redistribution behavior were attributed to the magnetic force and the Lorentz force, which can participate in a “cooperative” or “contrary” relationship depending on the magnetic susceptibility of the solute. This research helps clarify the solute redistribution behavior during eutectic alloy solidification under a high magnetic field, providing further theoretical basis for the modulation of alloy microstructures and properties by implementing high magnetic field-assisted solidification.