Climate targets set by the EU, including the reduction of CO₂, are leading to the increased use of lightweight materials for mass production such as press hardening steels. Besides sheet metal forming for high-strength components, tubular or profile forming (Hot Metal Gas Forming—HMGF) allows for designs that are more complex in combination with a lower weight. This paper particularly examines the application of conductive heating of the component for the combined press hardening process. The previous Finite-Element-Method (FEM)-supported design of an industry-oriented, curved component geometry allows the development of forming tools and process peripherals with a high degree of reliability. This work comprises a description regarding the functionality of the tools and the heating strategy for the curved component as well as the measurement technology used to investigate the heat distribution in the component during the conduction process. Subsequently, forming tests are carried out, material characterization is performed by hardness measurements in relevant areas of the component, and the FEM simulation is validated by comparing the resulting sheet thickness distribution to the experimental one.

Press hardening of steels for the production of car body components is very common. The reason for this is that the process allows the use of blanks with low wall thickness and the production of ultra-high strength components with complex geometries. The Hot Metal Gas Forming (HMGF) process for closed profiles combines the advantages of hydroforming, such as increased rigidity, functional integration or elimination of joining operations, with those of press hardening. In this paper results of continuous tests with actively cooled tools are presented in combination with temperature and displacement measurement. Furthermore, test results for HMGF with tool integrated conductive heating are demonstrated. Tests were done with tube material PHS1800 by SSAB, part temperatures over the Point of austenitisation and maximum internal pressure of 70 MPa. Thermocouples recorded the heat distribution in the tools. Other measured and recorded variables were the displacement of the component wall while forming under increasing internal pressure by a tactile displacement sensor and simultaneous temperature of its surface with a thermal sensor head. For the first time, information on pressure, the corresponding deformation stage and temperature profile could be documented during an entire forming step. A close to series production geometry DP4 was used to investigate the tool-integrated conductive heating of components.

With the increasing electrification of mobility and the associated growing demand for electric machines, issues of efficient and resource-saving production and operation are becoming ever more central. Therefore, it is important to optimize the design of components, materials and the assembly of electric machines. An example, described in the paper, shows how to increase the slot fill factor of a stator. By optimising the wire content in the slots, electric machines can be made smaller or, at the same size, operate more powerfully resp. efficiently. Various applicable production methods have different drawbacks such as low productivity, high energy and resource consumption, and restrictions for geometric design. Here, forming technology offers remedy in the utilization of material with simple tools and its suitability for mass production. This paper shows the analysed process chain developed at Fraunhofer IWU for the forming-based production of coils with trapezoidal cross-sectional geometry. The investigation results provide a more sustainable structure and an efficient process chain.

Due to new requirements regarding the efficiency of electrical machines it is necessary to steadily improve machine concepts or create new ones. Therefore, manufacturing technology has to be continuously improved, adapted or developed new. Forming technology offers an excellent opportunity to implement components for highly efficient electrical machines through its advantages regarding high productivity and high degree of material usage. This paper presents a new method for bending complete stacks of grain oriented electric sheets for use as radially laminated modules in an innovative machine concept with flux barriers. First, the principle of electric drives with flux barriers and the arrangement of the new radial lamination are explained. Then, practical preliminary studies concerning the bending of single sheets are performed. Based on this, the process and tooling for bending of pre-stacked sheets is developed and analysed. Accordingly, an increase in material utilisation of about 30% can be expected compared to classically designed stators. Furthermore, the use of the radially laminated stator principle increases the slot area by about 20% which makes it possible to insert more copper into the slot and thus increase the efficiency of the machine during operation. After validation of the process chain with a demonstrator motor and description of several manufacturing and quality improvements, finally, an outlook is given, and possible further research approaches are discussed.