may be used as a basis for understanding the impact of the working length, as well as determining conditions under which parent will weld in MPW. Conclusions The presented research has shown three basic regimes for flyer deformation based on its absolute axial position within a MPW coil. If the flyer is placed entirely through the coil, a twofront process ensues, in which the flyer contacts the parent first at the coil center, then propagates outwardly. In the current experiments, coils with widths of 10 and 15 mm displayed similar properties with regard to the impact on front characteristics. At working distances smaller than 7 mm, impact between the flyer and parent occurs first at the flyer edge, and propagates along a single front. At working distances between 8 mm and the coil width, a transition regime was seen in which the front propagated in a flat manner, hindering jet creation or escape, and thus obstructing welding processes. The transition regime is thought to provide suboptimal conditions for MPW processes. Additionally, information pertaining to coil optimization could be gathered. Coils with shorter maximum working zone lcoil and configurations where lw was positioned relative to the 90-deg coil edge produced higher impact velocities. Coils with smaller lcoil also increased the impact angle for a given energy. Additionally, the orientation of the workpiece and coil width in the utilized experiments influenced the magnetic field experienced by the flyer and, accordingly, the impact velocity and tendency toward producing a sound weld. This work is based on the results of subproject A1 of the priority program 1640 (“joining by plastic deformation”); the authors would like to thank the German Research Foundation (DFG) for its financial support. The authors would also like to thank Bmax for allowing us to perform experiments at its facilities in Toulouse, France. 1. 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