The solidified structure of ZK60 magnesium alloys in the presence and absence of electromagnetic
stirring during the solidification process was compared, and the precipitates of ZK60 magnesium alloys
were analyzed after a solution heat treatment using optical microscopy, micro-hardness analysis, X-ray
diffraction and scanning electron microscopy. The results showed that the microstructure of cast alloys
under a low-frequency alternating magnetic field (LFAMF) was mainly composed of a primary
crystalline Mg matrix and a non-equilibrium eutectic structure (MgþMgZnþMgZn2). In comparison
with the microstructure observed in the absence of the electromagnetic field, the eutectic network
structure on the grain boundary under low-frequency alternating magnetic field was finer and
exhibited a more uniform grain distribution. The grains under the LFAMF were refined in comparison
with those under no electromagnetic field before the solution heat treatment, and the former grain
distribution was more uniform than the latter after the solution heat treatment. The more uniform
grain distribution is because the solution heat treatment is conducive to the dissolution of the second
phase particles. The hardness exhibited a downward trend with increasing solution heat treatment
time. Under the same solution heat treatment, the hardness value of the samples prepared under the
LFAMF was lower than those prepared in the absence of the electromagnetic field. In contrast, the
mechanical properties of alloys prepared under the LFAMF were better than those prepared in the
absence of the electromagnetic field.