Effects Of Misch Metal And Y On The Microstructure And Mechanical Properties Of AZ80Mgnesium Alloy

In the present work, the effects of Misch metal and Y on AZ80Magnesium alloy were been investigated. By using optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and universal tensile testing machine, the microstructures and mechanical properties of AZ80Magnesium alloy with addition of Misch metal and Y were investigated systematically and the mechanism of grain refinement and aging treatment process were studied in details. Experiment results are obtained as follows:With the addition of Misch metal, the cast AZ80Magnesium alloy mainly consisted of α-Mg matrix+network-like β-Mg17Al12phase+block-shaped Al4Mn particles+slab-shaped Al11RE3(RE standing for Ce and La) particles. With the increases of the Misch metal content, the continuous network-like eutectic phase becomes fine and discontinuous, the grain size has been continuously reduce. After homogenization and extrusion, the mechanical properties are greatly improved, the extruded alloy with0.2wt.%Misch metal obtain the best mechanical properties, the UTS, YS and EL are329MPa,224MPa and16%, respectively.With the addition of0.4wt.%Y, the cast AZ80Magnesium alloy mainly consisted of α-Mg matrix+network-like β-Mg17Al12phase+ block-shaped Al4Mn particles and Al2Y particles, the average grain size is about100μm. After homogenization and multi-directional forging, the mechanical properties of wrought alloy are greatly improved, the UTS, YS and EL are345MPa,226MPa and9.2%, respectively.After extrusion and175℃×16h aging treatment, the AZ80+0.2wt.%RE Magnesium alloy is peak-aged and obtain the best mechanical properties, the UTS, YS and EL are354MPa,226MPa and9.4%, respectively. After multi-directional forging and175℃×30h aging treatment, the AZ80+0.4wt.%Y Magnesium alloy is peak-aged and obtain the best mechanical properties, the UTS, YS and EL are387MPa,277MPa and6%, respectively.