Unveiling the interplay of deformation mechanism in wrought Mg–Sc alloy with different content of manganese

Abstract

Within the scope of this study, the evolution of microstructures and mechanical properties in as-extruded Mg–Sc alloys were systematically explored with Mn content from 0.3 to 0.9 wt.%. The results showed that a completely recrystallized crystal structure was obtained in Mg-xMn-Sc alloys, and the average grain size decreased from 12.75 to 3.35 μm with the increase of Mn content. In addition, the increment of Mn content reduced the texture intensity from 14.95 to 7.65. Thus, Mg–Sc alloys’ tensile yield and ultimate strength significantly improved. Meanwhile, Mn addition led to the activation of non-basal slip, especially prismatic slip, which significantly enhanced the ductility of alloys. Moreover, the activation of non-basal slip by alloying Mn can be attributed to the reduction of the critical shear stress (CRSS) gap between basal slip and non-basal slip.

Keywords

• Magnesium alloy
• Deformation mechanisms
• Ductility
• <c+a> dislocation
• Critical shear stress