A posteriori optimisation of the forming pressure in superplastic forming processes by the finite element method

In order to optimise the superplastic forming processes, it is necessary to control the strain-rate induced in the material by the pressure gas. This control ensures high material deformability. In this paper, to determine the optimum pressure-time profile in superplastic forming processes, the authors will show an original technique based on finite element method. The proposed technique was tested with reference to the superplastic forming of a thin circular plate clamped in a rigid die and formed by a pressure differential. The experimental activity was carried out using a Pb/Sn-based metallic alloy. Final results of the finite element modelling agree with the experimental ones. (C) 2002 Elsevier B.V. All rights reserved.