Distribution of solute elements in AZ61 magnesium alloys under electromagnetic fields

The solidified microstructures of AZ61 magnesium alloy under different electromagnetic and electric fields were studied. Optical microstructure revealed that when the alloy solidified under single magnetostatic field, the constituent phase consisted of magnesium matrix and continuous cellular Mg–Al–Zn intermetallic compounds; when the alloy solidified under magnetostatic field and alternating current, the constituent phase consisted of magnesium matrix and spotted and cellular Mg–Al–Zn intermetallic compounds; when the alloy solidified under magnetostatic field and direct current, the continuous cellular structure disappeared and a few discontinuous flaky Mg–Al–Zn intermetallic compounds distributed in the magnesium matrix. As compared with the solute content under single magnetostatic field, the solute content in grain interior increased and that in grain boundaries decreased under magnetostatic field and current. Hence, the AZ61 magnesium alloy was strengthened under magnetostatic field and current.