Compared to conventional joining techniques, electromagnetic pulse welding offers important advantages especially when it comes to dissimilar material connections as e.g. copper aluminum welds. However, due to missing guidelines and tools for process design, the process has not been widely implemented in industrial production, yet. In order to contribute to overcoming this obstacle, a combined numerical and experimental process analysis for electromagnetic pulse welding of Cu-DHP and EN AW-1050 was carried out and the results were consolidated in a quantitative collision parameter based process window.

High-speed forming processes such as electromagnetic forming (EMF) and electrohydraulic forming (EHF) have a high potential for producing lightweight components with complex geometries, but the forming zone is usually limited to a small size for equipment-related reasons. Incremental strategies overcome this limit by using a sequence of local deformations to form larger component areas gradually. Hence, the technological potential of high-speed forming can be exploited for large-area components too. The target-oriented process design of such incremental forming operations requires a deep understanding of the underlying electromagnetic and electrohydraulic forming processes. This article therefore analyzes and compares the influence of fundamental process parameters on the acting loads, the resulting course of deformation, and the forming result for both technologies via experimental and numerical investigations. Specifically, it is shown that for the EHF process considered, the electrode distance and the discharge energy have a significant influence on the resulting forming depth. In the EHF process, the largest forming depth is achieved directly below the electrodes, while the pressure distribution in the EMF depends on the fieldshaper used. The energy requirement for the EHF process is comparatively low, while significantly higher forming speeds are achieved with the EMF process.

High speed velocity effects in production technology provide a broad range of technological and economic advantages [1, 2]. However, exploiting them necessitates the knowledge of strain rate dependent material behavior in process modelling. In general, high speed material data characterization features several difficulties and requires sophisticated approaches in order to provide reliable material data. This paper proposes two innovative concepts with electromagnetic and pneumatic drive and an approach for material characterization in terms of strain rate dependent flow curves and parameters of failure or damage models. The test setups have been designed for investigations of strain rates up to 10⁵ s^-1. In principle, knowledge about the temporary courses and local distributions of stress and strain in the specimen is essential for identifying material characteristics, but short process times, fast changes of the measurement values, small specimen size and frequently limited accessibility of the specimen during the test hinder directly measuring these parameters at high-velocity testing. Therefore, auxiliary test parameters, which are easier to measure, are recorded and used as input data for an inverse numerical simulation that provides the desired material characteristics, e.g. the Johnson-Cook parameters, as a result. These parameters are a force equivalent strain signal on a measurement body and the displacement of the upper specimen edge.

The use of high-speed forming technologies can contribute to satisfying current social and political demands on production technology such as sustainability and climate protection in manufacturing. These technologies have a very high potential for shaping complex, sharp-edged parts and constitute a key means of reducing a component’s weight. One exemplary high-speed forming technology is electromagnetic forming. It uses the energy density of pulsed magnetic fields to impose forces on electrically conductive materials, which leads to plastic deformation when reaching the yield stress of the material. However, for very thin sheet materials this effect can result in an uncontrolled deformation of the work piece. In order to overcome this effect, electromagnetically driven tools the use of can be appropriate. An additional benefit is that this process is no longer restricted to electrically highly conductive work piece materials. This paper describes a media-based process using electromagnetically driven tools to form micro-flow channels, which are often used in bipolar plates, into thin sheet metals. The principles are explained and first results are shown.

Magnetic pulse welding is a solid state welding process using pulsed magnetic fields resulting from a sudden discharge of a capacitor battery through a tool coil in order to cause a high-speed collision of two metallic components, thus producing an impact-welded joint. The joint is formed at room temperature. Consequently, temperature-induced problems are avoided and this technology enables the use of material combinations, which are usually considered to be non-weldable. The extension of the typically linear weld seam can easily reach several hundred millimetres in length, but only a few millimetres in width. If a larger connected area is required, incremental or sequential magnetic pulse welding is a promising alternative. Here, the inductor is moved relative to the joining partners after the first weld sequence and then another welding process is initiated. Thus, the welded area is extended gradually by arranging multiple adjacent weld seams. This paper demonstrates the feasibility of incremental magnetic pulse welding. Furthermore, the influence of important process parameters on the component quality is investigated and evaluated in terms of geometry and micrographic analysis. Moreover, the suitability of different mechanical testing methods is discussed for determining the strength of the individual weld seams.

Research activities considering lightweight design are dedicated to substituting classic mild steels by light metal alloys. Magnesium is especially promising due to its beneficial strength–density ratio, but its industrial use is still limited due to, e.g., unfavorable corrosion properties. Thus, a methodology for applying thin aluminum layers to magnesium base material by hot roll cladding has been developed. This paper characterizes the compound via peel tests, lap shear tests, Nakajima tests and deep drawing tests, thus identifying beneficial process parameters. It proves high interlaminar adhesion strength and significantly better formability then the bare magnesium core material.