Thermo-mechanical forming procedure of high strength Aluminum sheet with improved mechanical properties and process efficiency

Abstract

Abstract The rapidly rising demand of light-weight materials, especially high-strength Aluminum alloys, for structural components in the automotive and aerospace industries generates new challenges for the current metal producers and fabricators during the complex production and manufacturing process. However, a novel forming process for heat treatable Aluminum alloys - combining solution heat treatment and hot forming - promises a considerable improvement of formability with limited springback compared to the conventional forming techniques and, at the same time, the potential to improve mechanical properties and reduce processing times. In this study especially the effect of the solution heat treatment parameters on the improvement of mechanical properties of two different Aluminum sheet materials AA6082-T6 and AA7075-T6 is investigated. The impact and significance of the individual steps on the resulting properties and on the strengthening and formability behavior is characterized with the help of common material testing methods. A definite influence on the mechanical properties in the pre-aged as well as in the final aged condition is revealed with increasing heating rate, solution annealing temperature and duration as well as increasing cooling rate. On top of that a process time reducing interdependence of the parameters is observed, for instance increasing heating rates influence the dissolution kinetics and reduce significantly the necessary soaking time.