The effect of rotary swaging on the structure and mechanical properties of Mg-Y-Gd-Zr alloys additionally alloyed with samarium

The results of a study on the structure and mechanical properties of magnesium alloys containing 3-5 wt% yttrium, 4-7 wt% gadolinium, and 0-2.5 wt% samarium, processed by rotary swaging, are presented. It is shown that rotary swaging significantly enhances the strength of the studied alloys by grain refinement and twinning. The kinetics of the strengthening of deformed alloys during isothermal aging at 200 degrees C was examined. The aging process after rotary swaging leads to additional strengthening of the alloys due to the decomposition of the supersaturated magnesium solid solution, resulting in the formation of the beta' (cbco) phase. The features of dynamic recrystallization during deformation and strengthening during aging depends on the content of samarium. The mechanical properties were assessed both after rotary swaging and after the combination of rotary swaging and aging processes, with the latter yielding the highest strength. The effect of intermediate annealing at 515 degrees C following rotary swaging on the microstructure, aging response, and mechanical properties of the deformed alloys was analyzed. The findings indicate that annealing leads to an increase in grain size due to coalescent recrystallization that subsequently reduces the overall strength of the alloys.