Improvement of Yield Asymmetry and Enhancement of Mechanical Properties of Extruded AZ110 Alloy with La-Rich Misch Metal Addition

In this paper, effects of the La-rich MM (Misch Metal) on the microstructure, texture and mechanical properties of extruded AZ110 alloy during tension and compression deformation were investigated. High strength and low tension–compression yield asymmetry of AZ110MM alloy (AZ110 alloy with La-rich MM addition) are developed by hot extrusion. The addition of La-rich MM brings Al-RE phases (Al2(La, Ce) and Al11(La, Ce)3) to the as-cast AZ110 alloy, which play an important role in the grain refinement and texture weakening during extrusion deformation. Such grain refinement and texture weakening obviously inhibit the nucleation and growth of twins and make the deformation mechanism change from twinning to multiple slip during cold compression deformation. Furthermore, the Al-RE phases also improve the tension–compression yield asymmetry performance of the extruded AZ110 alloy via the combining effects of grain refinement, texture weakening and the transformation from twinning to multiple slip. Moreover, the extruded AZ110MM alloy shows much higher strength over AZ110 alloy, owning to texture effect, grain boundary strengthening and precipitation strengthening.