Microstructure and Properties of Experimental Mg-9Al-5RE-1Zn-Mn Magnesium Alloy

In this paper, an experimental Mg-Al-RE-type magnesium alloy, named AEZ951, is presented.The chemical composition of the investigated alloy was ca. 9 wt% Al, 5 wt% RE (rare earth elements), 0.7 wt% Zn and 3 wt% Mn.The experimental material was gravity cast into a cold steel mould.Microstructure analyses were carried out by light microscopy, along with X-ray phase analysis and scanning electron microscopy with an energy-dispersive X-ray spectrometer (SEM + EDX).Detailed investigations disclosed the presence of primary dendrites of an (Mg) solid solution and Al11RE3,  and Al10RE2Mn7 intermetallic compounds in the alloy microstructure.The volume fraction of the Al11RE3 phase and + eutectic was also presented.The hardness, impact strength, tensile strength as well as the yield strength of the alloy were examined in tests at room temperature.The examined experimental Mg-Al-RE-type magnesium alloy exhibited higher mechanical properties than the commercial AZ91 alloy (cast in the same conditions).