Microstructure and Mechanical Properties of Characteristic Regions Inside Mold During Mg–Al–Zn Alloy Extrusion Processing

The microstructure and mechanical properties of AZ33 magnesium alloy during forward extrusion processing have been investigated in this paper. The results showed that three characteristic regions exist in the extrusion die, namely dead metal zone (dead zone), shear deformation zone (shear zone), and normal flow zone (normal zone) according to apparently uneven flow behavior. The microstructure of three characteristic zones exhibits a recrystallized, heterogeneous deformation feature. An obvious mechanical anisotropy is obtained in the AZ33 alloy inside the extrusion die. The sample of the normal zone exhibits extraordinary ultimate compression strength of 282.86 MPa but the lowest compression yield strength of 163.99 MPa due to typical (0002)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ (0002) $$\end{document}//ED fiber texture. However, the highest compression yield strength of 210.56 MPa achieved in the dead zone is attributed to dislocations hardening and the refinement hardening effect via twin lamellae.