Improvement of anisotropic tensile properties of Al-7.9Zn-2.7Mg-2.0Cu alloy sheets by particle stimulated nucleation

The annealing treatment and homogenization were applied in Al-7.9Zn-2.7Mg-2.0Cu alloy before the hot rolling process to control the second-phase particles. The second-phase particles remained after annealing treatment and most of the second phases dissolved into the matrix after the homogenization. Particle stimulated nucleation (PSN) occurred in the annealed specimen during the hot rolling process. Large number of equiaxed dynamically recrystallized grains with random orientations formed around the coarse particles, and the PSN accelerated the recrystallization, which resulted in grain refinement. The PSN enhanced the strength and elongation along transverse direction in the studied alloy sheet, which improved the tensile properties anisotropy. (c) 2020 Elsevier B.V. All rights reserved.