Microstructural evolution and mechanical properties of 2219 aluminum alloy from different aging treatments to subsequent electromagnetic forming

Abstract

The manufacturing process of 2219 aluminum alloy (AA2219) thin-walled parts nowadays exhibits challenging to meet the service requirements of the high performance and lightweight new-generation launch vehicle. This work employs different aging treatments and subsequent electromagnetic forming to investigate the microstructure evolution and mechanical properties of AA2219. The results show that the optimal single aging treatment is 180 °C for 6 h, and the optimal double aging treatment through L 16 (4 4 ) orthogonal experimental is 140 °C for 2 h + 180 °C for 6 h. Meanwhile, the precipitated phase of single aging is mainly θ″ phase with a three-layer Cu atomic structure while double aging is mainly θ″ phase with a two-layer Cu atomic structure and GP zones. The average thickness and size of θ″ phase and GP zones in the double aged sample are smaller than that of θ″ phase in the single aged sample. However, it has a higher number density and more concentrated size distribution. The plasticity of aged AA2219 improved obviously under the electromagnetic forming. Besides, the forming performance of double aged sample is better with the tensile strength after electromagnetic forming is 424.0 MPa, and the total strain is 25.75%. Electromagnetic forming has negligible effects on the morphology, size, and distribution of precipitated phase. Nevertheless, some dislocations sheared θ″ phase along the {111}<110> slip system under tensile loading. The interaction mechanism of dislocation with different precipitated phases during electromagnetic forming was depicted. This work provides guidance for the strengthening treatment and forming process of AA2219 high-performance parts. • The morphology, size, and distribution of the precipitated phase were investigated. • The plasticity of aged 2219 aluminum alloy improved obviously under the electromagnetic forming. • The interaction mechanisms of dislocation with precipitated phase were depicted.