Toward an efficient industrial implementation of W-temper forming for 7xxx series Al alloys

Manufacturing technologies for parts made from ultra-high-strength 7xxx series aluminum sheet material have been the focus of research in recent years. A promising approach is W-temper forming, where sheet material is cold formed after heat treatment. Conventional heat treatment routes are very time-consuming and inefficient. In this study, a new more efficient and industry-orientated transfer tool concept has been developed. Heating and cooling of the sheets take place in separate contact tempering stages, which allow superior heating and cooling rates in comparison to conventional methods. To analyze the influences of temperature rates and deformation on microstructure and mechanical behavior, thermo-mechanical experiments in a Gleeble simulator were carried out. The results prove the great potential of the transfer tool concept with inline heat treatment for series production. The process-dependent mechanical properties determine a suitable process window for the industrial application of the W-temper forming of the analyzed alloys.