ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
A new welding method, magnetic pressure seam welding, was used to lap join dissimilarmetals (Al-Fe, Al-Ni and Al-Cu). The circuit for magnetic pressure seam welding consists of acapacitor, an electric discharge gap switch, and a plate-type coil. The overlapped metal plates areplaced over the coil. When an impulse current from an energy-storage capacitor bank passes throughthe coil, a high-density magnetic flux is suddenly generated around the coil. The generatedhigh-density magnetic flux lines cross the end of the overlapped plates. Eddy currents are inducedmainly inside the Al plate because it has a high electrical conductivity. Both the Joule heat generatedin the plates and the magnetic pressure applied from the Al side promote the joining of the lappedplates. The welding is normally achieved within 10 μs. This results in very little microstructuralchange in the parent plates aside from the area around the weld interface. Strong lap joints wereobtained for every metal combination and no tensile fracture took place in the weld region. Acharacteristic wavy morphology was observed at the weld interface. An intermediate phase layer wasalso observed at the weld interface. TEM observation revealed that the intermediate layer consisted offine Al grains and intermetallic compound particles dispersed among the Al grains. The growthdirection of the wave, the welding condition dependency of the wavelength and the amplitude of theinterfacial wave were intensively investigated in order to clarify the welding mechanism of thismethod
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.519-521.1145.pdf
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