Magnetic pulse welding

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Magnetic pulse welding (MPW) is a welding process that uses magnetic forces to drive, and weld two workpieces together. The welding mechanism is most similar to that in explosion welding.[1]

Process[edit]

A very high AC current (the "primary current") is passed through a conductive coil (the "inductor") near an electrically conductive material (the "flyer"). An intense magnetic field is locally produced that generates a secondary eddy current in the flyer according to Lenz's Law. The net effect of the secondary current moving in the primary magnetic field is the generation of a Lorentz force, which accelerates the flyer at a very high velocity. A stationary material (base material) is positioned in the trajectory of the flyer thus producing an impact which causes a solid state weld. Magnetic pulse welding may be used to join dissimilar metals.

Primary currents as high as 1 million amperes are used and flyer velocities in the vicinity of 800 meters per second can be achieved over a distance of a few millimeters. The magnetic pulse welding system is a high frequency capacitor discharge circuit (RLC circuit) often with extreme energy and power characteristics. System energies as high as 100 kJ, power of up to 1 GW and magnetic field intensities of 50 teslas and higher can be seen, which can propel certain materials at extreme velocities of 600 to 1000 m/s.

References[edit]

  1. ^ Weman, Klas (2003), Welding processes handbook, CRC Press, pp. 91–92, ISBN 978-0-8493-1773-6. 

2. S.D. Kore, J. Imbert, M. Worswick, Y. Zhou, Book chapter on Magnetic Pulse Welding, in ASM Handbook on “Solid-State Welding Processes”, Oct 2011

External links[edit]