Study on superplastic blow-forming in a rectangular closed-die

摘要

The objective of this paper is to explore the plastic deformation behavior of the sheet during blow-forming a superplastic sheet into a rectangular closed-die by the finite element method. A finite element commercial code "DEFORM" is used to carry out the simulations and calculate the pressurization profile and the sheet thickness distribution during the blow-forming process. A pressure control algorithm is proposed to keep the maximum strain rate in the deformation zone of the sheet equal to the target value, which corresponds to the highest m-value of the material being SPFed. The thickness distributions of the formed product using constant pressure control and keeping target strain rate control are compared. Experiments using 8090 Al-Li sheets on superplastic blow-forming in a rectangular closed-die are also carried out. The theoretical predictions of thickness distribution of the product are compared with experimental results.