Magnetic pulse joining of large-diameter tubes via novel field shaper

Magnetic pulse joining (MPJ) is widely used in high-tech industries due to its ultrafast processing, high efficiency and room-temperature metallurgical joining. However, its low energy transfer efficiency limits its application in large-diameter tube joining. This study investigated the structural factors governing current distribution in the field shaper (FS) and achieved regulation of the current path through optimization of the cross-sectional geometry and incorporation of sidewall grooves, effectively suppressing the sidewall current and enhancing the energy transfer efficiency. Relative to a conventional FS, the novel FS boosted the peak Lorentz force by 49% and tube radial deformation by 96%.It reduced the discharge energy for joining Φ80 mm 5754 Al/10# Fe tubes by 36%. Under identical energy input, the joint strength increased by 285%. The novel FS therefore generates a pronounced magnetic field amplification effect, offering a viable route to extending the dimensional envelope of tubular MPJ applications.