P. A. Friedman, S. G. Luckey, Y. Luo, Ford Motor Company, Dearborn, MI
Superplastic forming (SPF) is a manufacturing process that has the potential to facilitate increased use of aluminum and magnesium in automobile body structures. Despite considerable advantages with regards to formability and tooling costs, the process has been mostly limited to low volume production due to relatively long cycle times and higher costs associated with fine-grain sheet materials. This paper focuses on the development of a novel process that integrates hot drawing with SPF to expand the forming limits of difficult to form materials as well as improve production efficiency by enabling significantly faster forming times. A commercially-available explicit finite element analysis (FEA) code was adopted to establish feasibility of the new forming process and to develop a prototype die with a deep-draw geometry. The predictive accuracy of the FEA tools was established in terms of thickness distribution and material draw-in by correlating simulation results with experiment. Forming trials verified that this novel technology can deliver a superior thickness profile and significantly decrease forming time as compared to conventional SPF. Furthermore, it has been demonstrated that this technology enables the forming of conventionally-processed aluminum and magnesium sheet into deep-draw panels that cannot otherwise be formed by conventional stamping or SPF processes.
Summary: Summary to come.
