Influence of Equal-Channel Angular Pressing on the Microstructure and Texture of Mg-Zn-Y-Zr-RE Alloy Sheets

Due to their high specific strength, rolled Magnesium sheets have excellent prerequisites for lightweight construction applications. However, the hexagonal crystal structure of Mg offers only few slip systems that can be activated at low temperature, thus limiting the ductility. Additionally, the pronounced texture of rolled Mg sheets further limits its cold formability. Equal-Channel Angular Pressing (ECAP) is a suitable way to tailor the crystallographic texture, refine the grains, and thus improve the formability of the sheets. Since it is a discontinuous process, deformation can be applied in different shear planes by rotating the sheets. The influence of these so-called process routes on the resulting microstructure of the sheets is investigated in this work using a Mg-Zn-Y-Zr-RE alloy. Already after the second ECAP pass, a noticeable grain size refinement could be achieved. Furthermore, experimental studies showed that the elongation at fracture at elevated temperatures of the Mg alloy can be increased by ECAP.