**Figure 22.**

*Grain size measurements on the cross sections of the extruded profiles: Square, Isosceles triangle, circle, and profiles 1, 2, and 3 of complex shape of cross sections and the billet (Ø100 mm) [28].*


### *Magnesium Alloys Structure and Properties*

#### **Table 1.**

*Grain size and hardness HV0.1 of magnesium alloys profiles after extrusion.*

deformation effect and let to choose adequate alloy for requirements of given possible application.

Research work using magnesium alloys AZ31, AZ61, AZ80, WE 43, and Mg alloy with Li for production of thin-walled profiles showed the potential of the backward extrusion process of magnesium alloys and KOBO extrusion process to apply them for aeronautical applications. It gives the possibility for indicating the best materials and parameters of the process to use, e.g., bridge dies to produce different types of complex shape of cross sections, which are the interest of aviation industry in light extruded products in order to save energy, costs, etc., by reducing aircraft weight.

