https://popups.uliege.be/esaform21/index.php?id=854 Publications of Auteurs Björn Beckschwarte fr 0 https://popups.uliege.be/esaform21/index.php?id=4337 Electromagnetic embossing enables the transfer of surface structures from forming dies to metal sheets at high forming speeds. For this purpose, the contactless forming force is provided by means of a magnetic field of a tool coil which interacts with an eddy current in the workpiece. In thin sheets which are completely penetrated by the magnetic field, the resulting Lorentz forces act as body forces that accelerate the workpiece onto the forming die. In addition to the body forces, also high strain rates can support the embossing of thin sheets. This investigation deals with the embossing of pyramidal structures in the submillimeter range and an aspect ratio of about 1 into thin aluminum sheets (3.0255 / Al99,5). In order to quantify the reproduced microstructures, their extent is determined by means of a lateral analysis. From this, the replicated height is derived. Up to now it has been possible to partially reproduce microstructures with a large aspect ratio in thin sheets. In addition, the changing surface roughness of the sheets is taken into account. Before embossing, the sheets exhibit a relatively rough surface with a rolled texture, which is smoothed by the impulse forming with an optical forming die. This study reveals basic approaches for the electromagnetic embossing of optical microstructures. Thu, 01 Apr 2021 18:11:22 +0200 Thu, 01 Apr 2021 18:11:22 +0200 https://popups.uliege.be/esaform21/index.php?id=4337 https://popups.uliege.be/esaform21/index.php?id=850 Electromagnetic forming is a contactless high-speed forming technique. In this process force transmission is initiated by an electromagnetic field provided by a tool coil. While forming thin sheet metal, the magnetic field is present in the whole depth of the sheet metal by definition. Thus, the magnetic field generates eddy currents in the complete sheet volume. The resulting Lorenz` forces act as body forces and are used for forming. Thereby high strain rates, high temperatures and multiaxial stress fields influence the plastic material properties of the workpiece. In this study, the plastic properties were investigated under real electromagnetic forming conditions. By varying process conditions like charge energy, sheet thickness and die material, the magnetic field and thus the plastic material properties were changed. To visualize the influence of the electromagnetic field, forming experiments were carried out. The strain of the formed sheets was measured. Furthermore, the forming forces were determined by measurements during the electromagnetic forming as well as by finite element simulations. With the measured strain and the determined forming force, a model for the plastic material behavior during electromagnetic forming was evolved. Sun, 21 Mar 2021 22:12:14 +0100 Fri, 02 Apr 2021 16:57:44 +0200 https://popups.uliege.be/esaform21/index.php?id=850