Grant: Alliance Grants

Superplastic forming (SPF) of aluminium is a process that allows very large deformations (~400%) with specific aluminium alloys when heated above ~500°C, making it possible to produce lightweight and complex parts. Although this process would be interesting for production of automotive body parts, the long heating times and slow deformation rates make it too slow to be economically viable for the automotive industry. Verbom, a word leader in sheet metal forming, has developed an improved and faster version of SPF, High-Speed Blow Forming (HSBF). Although HSBF can achieve production rates of about 10 to 30 parts per hour (PPH) required for luxury cars, it is still far from the long-term goal of 120 PPH required to make it viable for mass-market models. Previous work between UdS and Verbom has allowed identifying and validating the two core technologies required to achieve such production rates, direct resistance heating (DRH) and compliant sealing (CS): DRH allows very fast and uniform heating by generating heat within the sheets by the Joule effect, and CS allows faster forming rates by letting material "flow" within the mold during the gas pressurisation phase. Even if both these technologies have been demonstrated at the lab-scale, many uncertainties regarding scaling-up must still be addressed for them to be adopted by Verbom, notably the use of multiple power supplies in parallel for DRH and the use of 3D sealing interfaces for CS. The goal of this project is to pursue the development these technologies by validating them at relevant sizes and shape complexities, effectively taking them closer to implementation on Verbom's production lines and enabling Ultra High-Speed Blow Forming (UHSBF).