Magnetic pulse welding - welding of metal parts through collision. The acceleration and throwing of the parts to be welded is ensured by a pulsed electromagnetic field.
Magnetic-pulse welding is used in mechanical engineering for welding tubular parts between themselves, as well as with other parts, for flat parts along their outer and inner contours. The thickness range of parts to be welded by magnetic pulse welding is 0.5-2.5 mm.
Content
Entity
Magnetic-pulsed metal processing is based on the electromechanical interaction between the eddy currents induced in the walls of the workpiece when they are crossed by the magnetic lines of the pulsed magnetic field and the magnetic flux itself. In this case, the Lorentz force acts on the conductor with the induced current (the welded part) and the part flies out and hits the other welded part with great speed.
Welded parts can be installed both at an angle and parallel to each other. Angular placement allows for consistent movement of the contact zone when welding parts. The connection is formed as a result of an oblique impact of two metal metal parts with the formation of metal bonds between them. When parallel arranged, the pressure distribution along the generatrix of the missile part is uneven. It is smaller at the ends and larger in the middle.
The kinetic energy transmitted to the welded element being thrown depends on the number of turns of the inductor, the discharge voltage, and the capacitance of the capacitor. Upon receipt of strong magnetic fields (about 15 T.), the inductor heats up strongly, so liquid (liquid nitrogen, helium) cooling is used to cool it.
Weaknesses
- Magnetic pulse welding cannot be used to produce large area joints.
Benefits
- using a magnetic pulse method, you can weld almost any materials in microseconds;
- in comparison with explosion welding in magnetic-pulse welding, welded joints of minimum length are obtained, which are equally strong with the base metal;
- welding of parts in an environment with specified properties (vacuum, protective atmosphere and others) is allowed using a remote inductor separated by a non-metallic shell.
Equipment
Installation for magnetic-pulse welding include pulsed current generators of capacitive type with inductive load. In magnetic-pulse welding, discharge currents reach hundreds of thousands of amperes.
The switching devices of the installations are vacuum arresters, pressure arresters, atmospheric pressure arresters and ignitrons.
Inductors consist of a metal ( steel , tungsten ) spiral from one or more turns. The shape of the working surface of the spiral with repeats the shape of the workpiece.
Literature
Nikolaev G. A. Welding in mechanical engineering: a Handbook in 4 volumes. - M.: Mechanical Engineering, 1978 (1-4 tons).
Babkov, V.V. Special welding methods / V.V. Babkov // Building materials. - 2001. - No. 8. - S. 16-17.
Badianov, B.N. Handbook of Magnetic Pulse Processing of Metals. / B. N. Badyanov. - Ulyanovsk: publishing house Ulyanovsk State Technical University, 2000 - 405s.
Bely, I. I. Metal welding: a textbook for the training of workers in production / I. I. Bely; M .: "Higher School", 2001. - 309 p.
Blaschuk, V. E. Metal and welding: a training manual / V. E. Blaschuk; 3rd ed., Revised. and add. - Moscow: Stroyizdat, 2006. - 144p.
Bryukhanov, A.N. Welding processes in electronic engineering / A.N. Bryukhanov // Kommersant. - No. 217 (2820) dated 11/27/2003.
Kvasnitsky, V.V. Special welding methods: study guide / V.V. Kvasnitsky; Publishing House: Nikolaev, UDMTU, 2003 .-- 437 p.