| Semi-continuous casting is one of the popular ways to manufacture aluminum alloys.It could homogenize the alloy compositions in macro-size and improve ingot as-cast organization which would improve properties of Al alloys in large size,which is of great significance.In this research,the influence of electromagnetic field and melt intense shearing process on the macro-segregation in Al alloys was researched,which is the important part of the project of National Science Foundation,the mechanism research and regulation with external fields of macro-segregation in semi-continuous casting Al alloys.In this research,two parts were discussed.(1)The effect of low-frequency electromagnetic field and intense melt shearing on the 7050 Al alloy DC ingot macrostructure,microstructure and macrosegregation.(2)The influence of low-frequency electromagnetic field and intense melt shearing on the 2524 Al alloy DC ingot macro structure,microstructure and macro segregation.The results could be listed as follows.(1)The distribution trend of elements(such as Zn?Mg?Cu)in 7050 ingot radial direction were more uniform under the effect of low frequency electromagnetic casting(LFEC)?intense melt shearing and intense melt shearing with electromagnetic field.(2)During 7050 alloy DC casting process,the individual applying low frequency magnetic field can make ingot happening transformation of bulky columnar crystal with grain feathers to small isometric the columnar crystal.The individual applying intense melt shearing can also make ingot happening transformation of bulky columnar crystal with grain feathers to small isometric the columnar crystal.However,the refinement effect of intense melt shear on 7050 microstructure is better than that of low frequency electromagnetic.With combination of electromagnetic field and intense melt shear,refining effect of alloy is better than that of single applying low frequency strong electromagnetic and intense melt shearing.(3)The distribution trend of elements(such as Cu?Mg)in 2524 ingot radial direction were more uniform under the effect of low frequency electromagnetic casting(LFEC)?intense melt shearing and intense melt shearing with electromagnetic field.(4)During 2524 alloy DC casting process,the individual applying low frequency magnetic field can make ingot happening transformation of bulky columnar crystal with grain feathers to small isometric the columnar crystal.The individual applying intense melt shearing can also make ingot happening transformation of bulky columnar crystal with grain feathers to small isometric the columnar crystal.However,the refinement effect of intense melt shear on 7050 microstructure is better than that of low frequency electromagnetic.With combination of electromagnetic field and intense melt shear,refining effect of alloy is better than that of single applying low frequency strong electromagnetic and intense melt shearing. |
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