Influence of the flyer kinetics on magnetic pulse welding of tubes

In this paper, the influence of different pulse generators with their characteristic discharge frequencies on the process parameters of magnetic pulse welding (MPW) of aluminum EN AW-6060 tubes on steel C45 cylinders is analyzed. Experimental, numerical, and analytical investigations focus on the radial impact velocity vi,r, the time-dependent collision angle βt, and the impact pressure pi. The influence of the temporal course of the magnetic pressure pmt is discussed. It is shown that the minimum radial impact velocity required for welding with the same geometrical setup can be reduced significantly at low discharge frequencies compared to high ones. This is attributed to a different deformation behavior of the tubular flyer part and, consequently, more favorable collision angles. Geometric changes to the joining setup enable a targeted modification of βt and allow for a reduction of vi,r even at high-frequency systems. During the design of an MPW process it is essential to consider the pulse characteristics. The advanced analysis methods presented in this paper contribute to the targeted establishment of favorable collision conditions for MPW, taking the distinctive features of the applied equipment into account.