Texture and Tensile Properties of Three-Layered Titanium Clad-AZ31 Magnesium Alloy Sheet by Single-Pass Hot Rolling

In the present study, a three-layered Ti/AZ31/Ti clad sheet was produced by single-pass hot rolling. Metallurgical bonding between Ti and AZ31 was successfully achieved with a reduction of thickness 38% (sheet I) and 50% (sheet II). The micro-structure and mechanical behavior were analyzed using optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), electron backscatter diffraction (EBSD), nanoindentation, and tensile tests. The AZ31 layer in sheets I and II exhibited microstructures of shear bands and tensile twins {10 (1) over bar2} < 10 (1) over bar1 >. The shear bands acted as local strain concentration areas which led to the failure of the clad sheets with limited elongation. Heat treatment caused changes in the microstructure and mechanical properties of clad sheets due to static recrystallization (SRX) on twins and shear bands in the AZ31 layer. Recrystallized grains usually randomize the texture which led to weaken the strong deformed (0001) basal texture. Twins served as nucleation sites for grain growth during SRX. Tensile tests at room temperature showed significantly improved ductility of the clad sheets after heat treatment at 400 degrees C for 12 h. The results showed that the mechanical properties of clad sheet II are better than clad sheet I: Clad sheet II shows elongation 13% and 35% along the rolling direction (RD) for as-rolled and annealed clad sheet, respectively, whereas clad sheet I shows elongation 10% and 22% along RD for as-rolled and annealed clad sheet, respectively.