Thermal loads of working coils in electromagnetic sheet metal forming

Analysis and reduction of coil temperature rise in electromagnetic forming

“…The relatively high local temperature rise, which is often neglected in the coil design, is indeed a potential danger for the lifetime of the tool coil in long-term discharge sequences. Since the mechanical and electrical properties of the conductor materials are affected in an unfavorable manner with increasing temperatures (Gies et al, 2014), the conductors in the place where the maximum temperature occurs will easily exceed the allowable temperature and then it will cause considerable impact on the performance of the whole coil.…”

“…Detailed system parameters used in the simulation are given in Table 1. The thermal characteristics of AA5083 and Zylon are mainly obtained or derived from Gies et al (2014) and Peng et al (2005), respectively. In the following section, the basic equations and descriptions of the circuit, electromagnetic, thermal and mechanical models will be given and analyzed.…”

“…(2) The thermal loading of the tool coil. It is illustrated in many researches that a significant part of the initial charging energy will be generated in the tool coil because of Joule heating losses, which has been well discussed by Gies et al (2014). The considerable energy dissipation in the coil can cause a significant temperature rise in the EMF process and will have bad effects on the physical properties of both insulating and conductive materials, which in turn can damage interlayer insulation and decrease the coil life, especially in the case of high volume production with short cycle times.…”

“…Unfortunately, the cooling system will introduce significant new levels of design complexity. Recently, Gies et al (2014) made a detailed analysis of the coil temperature distribution and its influencing parameters (such as the workpiece material and cover layer thickness) in the EMF process by experimental and numerical studies. The obtained results are of practical value in optimizing the thermal characteristics of the coil to some extent.…”

Targeted Weld Seam Formation and Energy Reduction at Magnetic Pulse Welding (MPW)

“…The necessary high current densities cause high thermal loads on the tool coil. This Joule heating is influenced by the amount of discharge energy and the cycle time in sequential processes [5]. The higher the energy and the shorter the cycle time, the higher the heat input and the resulting tool coil temperature.…”