Reduction of plastic anisotropy and improved form-ability of novel magnesium alloy sheets through utilization of Equal-Channel Angular Pressing (ECAP)

In this project, the effect of different processing routes on the microstructure-texture and re-lated deformation and forming behavior of an Mg-Zn-Nd-Y-Zr alloy was investigated. Special emphasis was placed on the thermomechanical processing, related characterization (micro-structural and mechanical of processed samples) and understanding of involved deformation mechanisms (via crystal plasticity (CP) modelling approaches). To reach this goal, the use of Equal-Channel Angular Pressing (ECAP) to deform Mg sheets was the starting point. This technique was selected as the introduction of severe shear deformation allows to tailor the crystallographic texture for a specific deformation behavior. Samples processed via ECAP have shown an improvement in the uniaxial deformation behavior with well-balanced work hardening, good ductility, reduce planar yield asymmetry. Despite these improvements, it was found that the forming behavior under deep drawing state can be worse in comparison to oth-er thermomechanical processing approaches. In the frame of this project, the effect of cold rolling on the texture design of this type of alloy was systematically investigated. It was found that a basal texture can in principle reduce the earing behavior during deep drawing of this alloy type. Accordingly, an understanding of the meaning of the normal and planar anisotropy (related with different conditions of this alloy) is provided. Furthermore, through CP simula-tion, it was possible to provide a deep understanding of the influence of the activation of dif-ferent deformation mechanisms. In the last stages of the project, also the effect of recovery has been implemented to this type of analysis.