摘要
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=1.27×10^(5)A/m^(2),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 10^(2)–10^(3)μm.Finally,the upward continuous casting was conducted to validate the relative displacement range,and the experimental results matched well.
基金
financially supported by the National Natural Science Foundation of China(Nos.51904184,52204392,52274385,and 52204347)
the National Key Research and Development Program of China(No.2022YFC2904900)
the Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001).
