Magnetic pulse welding

From Wikipedia, the free encyclopedia

Magnetic pulse welding is a welding process in which a very high AC current (the "primary current") is passed through a conductive coil (the "inductor") in the vicinity of 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 path of the flyer thus producing an impact which in turn procues a solid state weld. Magnetic pulse welding may be used to join dissimilar metals.

Primary currents as high as 1 million amps 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 Tesla and higher can be seen, which can propel certain materials at extreme velocities of 600 to 1000 m/s.