The microstructure and tensile property of extruded Mg–6Zn–1.5Ca (wt%) alloy were examined by means of electron backscattered diffraction, scanning and transmission electron microscopy. A bimodal microstructure featuring fine dynamically recrystallized (DRXed) grains with weaker texture and coarse-deformed region with strong basal texture and fine precipitates was achieved in the as-extruded Mg–Zn–Ca alloy, which resulted in a yield strength as high as 305 MPa and a moderate elongation to fracture of 8.6%. Dynamic precipitation was detected in the deformed region, which inhibited the dynamic recrystallization process. The texture intensity in the DRXed region was weakened compared with that in the deformed region, which was associated with the preferred nucleation during dynamic recrystallization. Such texture weakening effects gave rise to an obvious ductility improvement for the as-annealed alloy.

Deformation mechanisms of a ZrTiAlV alloy with two ductile phases including a hexagonal close-packed (hcp) structure phase were investigated. A ZrTiAlV alloy was prepared via smelting, breakdown, forging, and suitable heat treatments. X-ray diffraction results show that the proposed ZrTiAlV alloy has two ductile phase structures, namely, hcp structure α-phase and bcc (body-centered cubic) structure β-phase. Scanning electron microscopy (SEM) results show that the plastic deformation of the examined ZrTiAlV alloy starts from the α-phase. Transmission electron microscopy (TEM) analysis shows that only dislocation slips can be found near fractured areas, and the main slip plane in the α-phase is the (0001) lattice plane. Both of the SEM and TEM results show the inexistence of deformation twin in the examined ZrTiAlV alloy including a hcp structure α-phase. Reasons for the abnormal deformation behavior of the hcp structure α-phase are also discussed.