Effects of solution and aging on microstructure of AZ80 magnesium alloy

The microstructure and element distribution of AZ80 magnesium alloy as-cast and after solution and aging treatment were observed and analyzed by field emission scanning electron microscope (FESEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The results show that the coarse and net β-Mg17Al12 phase distributed along the grain boundaries and dendrite is almost dissolved after solution treatment, only a little β-Mg17Al12 phase discon-tinuously distributed along the grain boundary, a little fine grain β-Mg17Al12 phase appears in the α-Mg matrix and the content of Al in the α-Mg matrix has increased remarkably. While after aging treatment, both discontinuous and continuous precipitations of β-Mg17Al12 phase occur in the structure of AZ80 alloy. The discontinuous precipitation that is fine lamellar structure distribute in the grain boundary. However, the continuous precipitation of β-Mg17Al12 phase with granular-like and lozenge-like distribute in the grains. The distributions of Mg and Al in the microstructure of aging treated AZ80 magnesium alloy are homogeneous.