Influence of deformation on microstructure, texture and mechanical properties of indirectly extruded Mg–Zn based alloys.Tuesday (05.11.2019) 16:55 - 17:15 Part of:
Extrusion processing is a widely used method for producing magnesium profiles. Mg-Zn based alloys modified with Ca and Nd were indirectly extruded at 300°C with different deformation rates, and the microstructure, texture and mechanical properties were investigated and discussed with respect to the processing based microstructure formation and its effect on the resulting mechanical properties. Alloy Z1 exhibits a coarse grained microstructure with no distinct variations due to changes in the extrusion speed. In ternary alloys with Nd or Ca the recrystallized fraction of the microstructure increased with the extrusion speed as well as the grain size. Our results indicate that the Nd addition delays the recrystallization process more than Ca. While the binary Mg-Zn alloy exhibits a distinct texture with aligned basal planes parallel to extrusion direction, Ca or Nd leads to the formation of a more random texture. Continuous and Discontinuous Dynamic Recrystallization mechanisms are involved in the texture formation of the alloys and the grain growth also affects the development of the final texture. The increment of the mechanical asymmetry is correlated to a large difference in the twinning activity between tension and compression in Z1 alloy. Although the activation of twinning is decreased, the mechanical asymmetry still exists in the Ca and Nd containing alloys. With increasing extrusion speed a reversed yield asymmetry is observed.