The
microstructure as well as
solute distribution both in microscopic and macroscopic view for 7075 alloy by
semi-continuous casting under the
electromagnetic vibration were investigated. The results show that there is an optimum frequency range of 10～30 Hz, in which, with the increasing of electromagnetic intensity, the quantity of spheroid-shaped grains increases; the quantity of rosette-shaped grains decreases, the microstructure of the ingot becomes more fine and uniform. At the mean time,
alloying elements'solubility increases and the
macro-segregation is diminished in a great degree. The electromagnetic vibration makes the grain nuclei in
sump increase, temperature and solute distribution of sump become uniform, primary solidified shell and sump height decrease, solute equilibrium partition coefficient increase and solidification temperature interval decrease, the effect of restraining crystal particles growing into dendrite strengthen, which promote alloying elements'solution inside crystal and suppress macro-segregation.