METHOD OF RESISTANCE WELDING

摘要

1482467 Welding by pressure TOYOTA JIDOSHA KOGYO KK 10 July 1974 [14 July 1973] 30659/74 Heading B3R At least one integral, tapered, flat topped projection of trapeziform cross-section is formed on a first metal member and is pressed against a second member of a different metal, welding current is passed across the members, the projection being heated so that only its top portion melts, the base of the projection remaining below the temperature at which it will plastically flow, and molten metal is squeezed out from between the projection and the second member. In an embodiment, a steel disc with a projection, Fig. 1, of trapeziform cross-section, around its periphery is resistance welded to a face of an aluminium cube and a similar steel disc is similarly welded to a cast iron cube, the end only of the projection melting and the molten metal being squeezed out by the remaining part of the projection (Fig. 6, not shown). In further embodiments a copper alloy disc having a projection of trapeziform cross-section around its periphery is resistance welded to an aluminium disc and a similar steel disc with a projection is similarly welded to a titanium disc. In another embodiment a steel disc having a peripheral projection is resistance welded to the end of a copper alloy tube. The projection may have a height of 2 mm., a width at the top of 0À5 mm. and the angle that its sides subtend with a perpendicular to its flat top may range from 7-35 degrees. The welding current density may be 0À75-3À4 KA/mm.2 of the flat top surface and the welding pressure may be 15-100 kg./mm.2 of the flat top surface. The welding current may flow for 0À5-10 cycles at 60 Hz.