Electromagnetic flanging: from elementary geometries to aeronautical components

Aeronautical companies are manufacturing many components of small (less than 200 mm) and medium (between 200 mm and 1000 mm) sizes by flexforming. In order to diversify the production facilities of these components, these companies are interested in evaluating the ability of electromagnetic forming processes to produce small parts. This paper describes the design of a set of experiments of electromagnetic flanging with some elementary geometries, whose purpose is to enlighten several geometrical defect issues encountered, and to propose some solutions. A particular attention is first paid to the straight flange, which allows to analyse, understand and then correct the main defect issues that can occur during the forming. The proposed solutions consist of some particular design of the inductors and the dies, in order to adjust the profile of the loading and the kinematics of bending of the flange to obtain the desired final geometry. Next, curved flanges are addressed, and finally the forming of a model aeronautical part combining several elementary geometries of flange is described. Promising results are obtained. In these experiments, sheets of 1, 2 and 1.6 mm thickness made of aluminium alloy 2024-T4 and sheets of 0.5 mm thickness made of aluminium alloy 1050 are used. The geometric dispersions and the material soundness of the parts have been controlled. Besides, a numerical model of the model aeronautical part has been developed in the LS-DYNA computing environment, whose final purpose is to facilitate the design of the coil. The results of the numerical simulations are shown to be qualitatively in accordance with experimental results.