Disclosed is a method of resistance welding between composite articles. A conductive element is provided between faying surfaces, having a plurality of lower resistivity electrode portions spaced apart along the length of the contact area between the composite articles. The electrode portions can be used to spot weld across the electrode portions, and along a longitudinal portion of the conductive element between the electrode portions by application of an electrical current. Also disclosed are apparatus for use in the resistance welding methods and composite articles and structures and elements incorporating the conductive element.

A method of securing a first component part and a second component part together, the method comprising providing an electrically conductive member between a first surface of the first component part and a facing first surface of the second component part and securing the first and second components together by passing a current through the electrically conductive member. The electrically conductive member is distributed across at least 50% of the surface area of the first surface of the first component part.

Disclosed is a method of resistance welding between composite articles. A conductive element is provided between faying surfaces, having a plurality of lower resistivity electrode portions spaced apart along the length of the contact area between the composite articles. The electrode portions can be used to spot weld across the electrode portions, and along a longitudinal portion of the conductive element between the electrode portions by application of an electrical current. Also disclosed are apparatus for use in the resistance welding methods and composite articles and structures and elements incorporating the conductive element.

A resistance spot welding system can join two polymeric workpieces and includes a power supply. The power supply has a positive terminal and a negative terminal. The resistance spot welding system further includes a welding electrode assembly electrically connected to the power supply. The welding electrode assembly includes a housing, a first electrically conductive pin and a second electrically conductive pin. The first and second electrically conductive pins both protrude from the housing. The first electrically conductive pin is electrically connected to the positive terminal of the power supply, and the second electrically conductive pin is electrically connected to the negative terminal of the power supply. The second electrically conductive material is electrically insulated from the first electrically conductive pin. The first and second electrically conductive pins are at least partly made of a material having a hardness ranging between 50 HRC and 70 HRC.

Disclosed is a method of resistance welding between composite articles. A conductive element is provided between faying surfaces, having a plurality of lower resistivity electrode portions spaced apart along the length of the contact area between the composite articles. The electrode portions can be used to spot weld across the electrode portions, and along a longitudinal portion of the conductive element between the electrode portions by application of an electrical current. Also disclosed are apparatus for use in the resistance welding methods and composite articles and structures and elements incorporating the conductive element.

A system for coupling pipes includes a first pipe having a tapered, spigot end; a second pipe having a tapered, spigot end; and a coupler having two tapered socket ends adapted to internally receive the respective tapered, spigot ends of the first pipe and the second pipe. The first pipe and the second pipe are made from a reinforced thermosetting resin (RTR). The coupler comprising a resistive element implanted therein and connected to electrodes extending to an exterior of the coupler. A thermoplastic material is disposed between an exterior of the first pipe and an interior of the coupler. A thermoplastic material is disposed between an exterior of the second pipe and the interior of the coupler. Upon application of electricity to the electrodes, the resistive elements are heated sufficiently to melt the thermoplastic material such that, when the heat is removed, the hardened thermoplastic material seals the first pipe and the second pipe to the coupler. A method of coupling pipes includes disposing a thermoplastic material between an exterior of a first pipe and an interior of a coupler; disposing a thermoplastic material between an exterior of a second pipe and the interior of the coupler; inserting the first pipe and the second pipe into the coupler; and applying of electricity to electrodes of the coupler such that resistive elements of the coupler heat sufficiently to melt the thermoplastic material such that, when the heat is removed, the hardened thermoplastic material seals the first pipe and the second pipe to the coupler.

A system for coupling pipes includes a first pipe having a tapered, spigot end; a second pipe having a tapered, spigot end; and a coupler having two tapered socket ends adapted to internally receive the respective tapered, spigot ends of the first pipe and the second pipe. The first pipe and the second pipe are made from a reinforced thermosetting resin (RTR). The coupler comprising a resistive element implanted therein and connected to electrodes extending to an exterior of the coupler. A thermoplastic material is disposed between an exterior of the first pipe and an interior of the coupler. A thermoplastic material is disposed between an exterior of the second pipe and the interior of the coupler. Upon application of electricity to the electrodes, the resistive elements are heated sufficiently to melt the thermoplastic material such that, when the heat is removed, the hardened thermoplastic material seals the first pipe and the second pipe to the coupler. A method of coupling pipes includes disposing a thermoplastic material between an exterior of a first pipe and an interior of a coupler; disposing a thermoplastic material between an exterior of a second pipe and the interior of the coupler; inserting the first pipe and the second pipe into the coupler; and applying of electricity to electrodes of the coupler such that resistive elements of the coupler heat sufficiently to melt the thermoplastic material such that, when the heat is removed, the hardened thermoplastic material seals the first pipe and the second pipe to the coupler.

A method of securing a first component part and a second component part together, the method comprising providing an electrically conductive member between a first surface of the first component part and a facing first surface of the second component part and securing the first and second components together by passing a current through the electrically conductive member. The electrically conductive member is distributed across at least 50% of the surface area of the first surface of the first component part.

A resistance spot welding method can be used to join polymeric and metallic workpieces together and includes the following steps: (a) placing an electrically conductive coating between a polymeric workpiece and a metallic workpiece, wherein the metallic workpiece has a textured surface facing the polymeric workpiece; (b) piercing the polymeric workpiece with first and second electrically conductive pins of a welding electrode assembly; (c) applying electrical energy to the first and second electrically conductive pins so that an electrical current flows through the first electrically conductive pin, the electrically conductive coating, and the second electrically conductive pin in order to at least partially melt the polymeric workpiece and the electrically conductive coating, thereby forming a weld pool; and (d) cooling the weld pool to form a solid weld nugget in order to establish a mechanical interface lock between the solid weld nugget and the textured surface.

Composite joints and methods of forming composite joints are presented. A composite joint comprising: a first composite component formed of one of a thermoset material or a first thermoplastic material; a second composite component formed of a thermoset material or a third thermoplastic material; a thermoplastic joining film formed of a second thermoplastic material between the first composite component and the second composite component, the second thermoplastic material different from the thermoset material, first thermoplastic material, and third thermoplastic material; and a carbon conductive layer in the thermoplastic joining film.