Abstract
This paper describes a lap welding technique for aluminum sheets with a gap (before welding) and its experimental results. When a high-density magnetic flux is suddenly generated inside a flat one-turn coil, eddy currents are induced in the overlapped ends of two aluminum sheets (thickness 1.0 mm each) placed inside the coil. As a result, an electromagnetic force acts on the two sheets and presses them together so that they collide with each other. If the moving velocity of the two sheets is high, the collided surfaces can be cleared by an effect of the collision that is known as explosive welding, and then can be joined both by the electromagnetic force on them and by the joule heat generated in them. A bank energy required for this lap seam welding of an area 5x50 mm^2 is less than 1 kJ.
