GB803736A - Improvements in or relating to resistance welding - Google Patents

Abstract

803,736. Making composite metal sheets; welding by pressure; brazing. FAIRCHILD ENGINE & AIRPLANE CORPORATION. May 10, 1956, No. 14602/56. Classes 83 (2) and 83 (4). In resistance welding the edges of a honeycomb core formed of thin metal strip to the face of a thicker metal sheet, a bonding material is disposed between the core and the face of the sheet and at least part of the material is caused to adhere to the core and the sheet by the heat of the weld or upon subsequent cooling, to reinforce the weld and form a connection between the core and sheet where the weld is discontinuous. In one embodiment, a fusible ceramic frit melting at a temperature below the' welding temperature or a thermo-setting initially liquid synthetic resin, e.g. polysiloxane, is applied at 16 by coating or dipping to the edges of a core 10 formed of stainless steel, e.g. 18-8 strips 11 welded at their contact points 12. Two stainless steel, e.g. 18-8 skins 14, 15 are then welded on the sides of the core by roller electrodes 17, 18 to form a honeycomb sandwich, the welding heat melting, at least locally, the ceramic material or partially polymerizing the synthetic resin. In a modification, a woven wire cloth 22 formed of brazing alloy, e.g. a nickel or silver alloy, is placed between each skin 14, 15 and the core 10 to be melted and connect the core edges and skins. The brazing alloy may be applied as a foil or as a suspension of particles in a vehicle. The work may be further heated in an oven after welding to complete the melting of the ceramic frit or the brazing alloy or to complete the polymerization of the resin. The method may be used when a metal wire web or cloth is disposed between the skins and core. The strips forming the core may be coated with a highly conductive metal, e.g. copper, silver, gold or aluminium, as described in Specification 792,165, and closely spaced points of contact between the core and skins as described in Specification 803,735 may be employed.