3. Experimental results
3.1 Texture characterization
The microstructure of the material was characterized by the EBSD technique before fatigue tests. Figure 2 displays the EBSD information of the cross-section of the material, including the grain orientation map, the pole figure, and the inverse pole figure. The striped phase in the grain orientation map in different colors is the α-Mg phase. It should be noted that the β-Li phase can not be resolved due to its high metal activity and high oxidation, thus it acts as a black matrix in the grain orientation map. The EBSD results, especially in the pole figure, show that the α-Mg phase exhibits a strong texture along the axial direction of the material, the grain orientation of most grains is around {10-10} and {11-20} (the cylindrical directions of the hexagonal close-packed structure). In other words, the basal plane of most grains is parallel or nearly parallel to the axial direction of the material. It is typical for the magnesium and its alloys to exhibit a texture after extrusion, which mainly results from recrystallization and a unidirectional deformation during extrusion [24-26].