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 discontinuously 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.