Evolution of texture, microstructure, tensile strength and corrosion properties of annealed Al–Mg–Sc–Zr alloys

The microstructure, texture, tensile strength, and corrosion behavior of Al–Mg–Sc–Zr alloy at different annealing temperatures were investigated using SEM, TEM, XRD, and dual potentiostat techniques. Results show that in the process of alloy homogenization annealing, the Al–Mg–Sc–Zr alloy is able to precipitate spherical particles of Al3(Sc, Zr) with a diameter of about 10 nm and a lattice constant of 0.41 nm, which can pin dislocation, hinder grain boundary movement, and suppress recrystallization. Moreover, the dislocations move to the grain boundaries during the annealing process, leading to the formation of dislocation walls. Remarkably, the sub-crystals are also formed as the grain boundaries parallel to {101}, and move to become parallel to {111}. The texture mainly consists of copper, brass, S, and R, and only a small amount of recrystallization cube texture. Furthermore, under the influence of the microstructure and texture, the strength of the alloy decreases, the plasticity increases, and the corrosion resistance first increases and then decreases. The optimal mechanical properties and corrosion resistance were obtained when the annealing was done at 300 °C for 1 h.