Abstract
The important factors which affect the result of electromagnetic welding will be i) inductance of coil, ii) clearance between outer tube and core bar, iii) tapered angle of core bar, iv) thickness of core; if a tube is used as a core, v) hardness of outer tube. Each of those factors was examined on some joints made of industrial pure aluminum. The main part of the welding equipment was the capacitor of capacitance of 1, 000μF and proof voltage of 5 kV. The result of welding was expressed by the ratio of welded length to interfacial length along the circumferencial direction. The results could be summerized as follows:
(1) The optimum result of welding was obtained by the coil inudctance of about 3μH.
(2) The most suitable clearance was 3mm.
(3) For the joint of straight core, two welds were obtained near the ends of the coil. They moved to inner sites of coil as the tapered angle increased up to 8 degree.
(4) The successful welding result was obtained for tube to tube joint, when the thickness of core tube exceeded about 6mm.
(5) The softer the outer tube, the more easily the welding was performed, if the energy input was constant.
