Revealing the influential mechanism of electromagnetic vibration on the bulk solidification and the upward continuous casting of Cu-15Ni-8Sn Alloy.

• The effects of EMV parameters (frequency, current density and magnetic flux density) were investigated. • Experiments and simulations are used to investigate the mechanism of EMV. • Effective grain refinement can be achieved only when the relative displacement falls within the range of 10²–10³ μm. • The proposed approach can be used to the continuous casting of other alloys. The effect of electromagnetic vibration (EMV) on the solidification structure of Cu-15Ni-8Sn alloy during bulk solidification and the upward continuous casting was investigated experimentally and numerically. The bulk solidification results indicated that in the case of B = 0.5 T and J = 1.27 × 10⁵ A/m², the most effective grain refinement frequency was at f = 10 Hz, where fine non-dendrites were obtained. The solidification structure became coarser at f = 0.1 Hz and f = 1 Hz compared to the case of f = 10 Hz, while no grain refinement was observed at f = 100 Hz. The numerical simulations showed that at f = 10 Hz, the strong melt convection surrounding the primary solid phase promotes the diffusion of the rejected solute, consequently, resulting in a reduction of the solute boundary layer, which leads to the decrease in the nucleation-free zone (NFZ) and the grain refinement. Additionally, the most effective grain refinement frequency transformed to 1 Hz when the electromagnetic force was reduced by five times. Moreover, we proposed that the most effective grain refinement frequency range aligns with the EMV-induced relative displacement in the range of 10²–10³ μm. Finally, the upward continuous casting was conducted to validate the relative displacement range, and the experimental results matched well. [Display omitted] [ABSTRACT FROM AUTHOR]