Study on the microstructure and mechanical properties of annealed TC4/6061/AZ31B/6061/TC4 symmetrical clad sheets

In this study, five-layer symmetric clad sheets of TC4/6061/AZ31B/6061/TC4 were successfully prepared by hot rolling, and then the clad sheets were subjected to annealing treatments with different annealing conditions. The effects of annealing treatments on the mechanical properties and microstructure were explored. The results showed that the recovery and recrystallization process of magnesium alloy were fully strengthened, and the thickness of the elemental diffusion layer at the Ti/Al and Al/Mg combined interface increased with the increase in annealing temperature and holding time. When the annealing temperature exceeded 300 degrees C, the Al/Mg combined interface generated two intermediate compounds, Al3Mg2 and Mg17Al12. Due to the existence of intermediate compounds, the mechanical properties of the clad sheets were greatly reduced, but the hardness value of the Al/Mg interface was higher than that of the center of the aluminum and magnesium layers. When the annealing temperature is 200 degrees C for 2 h, the tensile strength and the elongation of the clad sheets reach the maximum, and the magnesium layer has the most uniform grain organization at the same time.