Opportunities, Challenges, and Influencing Factors in the Forming of Preconditioned Semi‐Finished Products Made of EN AW‐6082 and ‐7075

Abstract

The aluminum alloys EN AW‐6082 and ‐7075 possess a high specific strength and are therefore predestined lightweight materials. In the high‐strength T6 state, however, they exhibit low cold formability and a pronounced springback. For this reason, temperature‐supported process routes such as warm or hot forming are currently used to form these alloys. Cold forming of preconditioned semi‐finished products in the W‐Temper (W) or soft‐annealed (O) condition offers an alternative. The upstream heat treatments lead to a significant expansion of formability, making conventional cold forming possible. This comes along with more robust process conditions. After the forming operations, a heat treatment is required to obtain the high‐strength T6 properties. Herein, the opportunities, but also the challenges, of preconditioning are highlighted on the basis of material characterization and single‐stage as well as multistage forming experiments. Special attention is paid to the relevant process variables and their influences regarding process robustness. This also includes subsequent heat treatment to exploit the lightweight potential.