Experimental Study on Texture Evolution of Mg-Y Magnesium Alloy in Extrusion

Abstract

The low lattice symmetry and limit deformation modes of wrought magnesium (Mg) alloys restrain it from wide use in aerospace and automobile industries. Addition of rare earth (RE) elements has been used as the texture modifier to improve the formability of Mg alloys. Mg-1Al and Mg-4Y extruded alloys were investigated to probe the effects of the Y addition on the texture and microstructure of Mg alloys. It is demonstrated that the non-RE alloys exhibit a $\left\{ {10\bar{1}0} \right\}$ or $\left\{ {10\bar{1}0} \right\} - \left\{ {11\bar{2}0} \right\}$ texture depending on the recrystallized fraction, whereas the yttrium (Y) Mg alloys develop a $\left\{ {11\bar{2}1} \right\}$ “RE texture” component. The mechanism of “RE texture” component’s formation was studied by using the electronic backscattered diffraction (EBSD) technique. The results indicate that the formation of both $\left\{ {11\bar{2}0} \right\}$ and $\left\{ {11\bar{2}1} \right\}$ texture components is closely related to the continuous dynamic recrystallization (CDRX) of the grains which nucleate in the mantle regions of the original grains.