Anisotropy of microstructure and properties of Al-10.22 Zn-2.87 Mg-1.2 Cu-0.213 Zr alloy

An aluminum alloy (Al-10.22Zn-2.87mg-1.2Cu-0.213Zr) with self-designed composition was used as the experimental object. Melting and casting, homogenization annealing and extrusion were carried out in sequence. The microstructure and properties of high strength aluminum alloy in different directions under the state of extrusion-hot pressing-solution-aging were preliminarily studied through XRD, hardness, conductivity, tensile strength, elongation and intergranular corrosion of the alloy in different directions. The results show that after subjecting the aluminum alloy to deformation and solid solution processes, the grains in the alloy undergo recrystallization, and the recrystallization degree in the S direction and the T direction is obviously greater than that in the L direction. Recrystallization does not occur substantially in the L direction. Part of dislocations remained in the alloy after the solution process which is a necessary condition to ensure high strength of the alloy. The alloy has the best comprehensive properties in the L direction, with 749 MPa tensile strength, 6.4% elongation, and 151.71 m maximum intergranular corrosion depth.