Comparison of the microstructure and the mechanical properties of AX41 magnesium alloy processed by EX-ECAP via three different routes A, Bc and C

This work is devoted to the creep-resistant AX41 magnesium alloy (Mg-4 wt.% Al-1 wt.% Ca), processed by extrusion and consecutive Equal Channel Angular Pressing (EX- ECAP) up to total of eight passes, via route A, Bc and C at 220 °C. Beyond the deformation behavior the change of the microstructures was studied by electron back-scattering and X-ray diffraction methods. Significant grain refinement was found for all processing routes (grain sizes decreased below 1 pm after 8 passes). The X-ray line profile analysis performed by Convolutional Multiple Whole Profile (CMWP) fitting method has not revealed differences between the particular dislocation structures. Route A was found to be the most effective processing route from the point of view of grain size refinement and the room temperature strength. The influence of the texture and the dislocation structure on the plastic deformation processes is discussed in detail.