Effects of an ultra-high magnetic field up to 25 T on the phase transformations of undercooled Co-B eutectic alloy

While there have been multiple recent reports in the literature focusing on the effects of magnetic field on the phase transformation behaviors, the research conducted with an ultra-high magnetic field greater than 20 T is still preliminary. In the current study, the structure evolution of Co-B alloys are experimentally studied with undercooling. The effects of a 25 T magnetic field on the solidification behavior and the subsequent solid-state phase transformation behavior have been investigated. The 25 T magnetic field is confirmed to have little effect on the homogeneous nucleation, but have some influence on the heterogeneous nucleation of Co₃B and Co₂₃B₆ phases by modifying the wetting angle θ. The decomposition of Co₂₃B₆ phase in the subsequent cooling process can be effectively suppressed by applying the 25 T magnetic field. The present work might be helpful for not only theoretically understanding the influence of ultra-high magnetic field on the phase transformation behaviors but a potential technology of field-manipulation of magnetic materials.