An implant for electric resistance welding of thermoplastic composites and a method of welding by means of the implant

An implant for electric resistance welding of elements made of composites, with a frame made of thermoplastic materials, in particular reinforced with conductive fibres, in the form of a flat multilayered structure which has an upper and a lower surface, and comprising the following layers:

• a) An electrically resistant layer, which has the form of a flat sheet with openings, made of a conductive material;
• b) At least two additional layers made of the frame material, one of which covers the electrically resistant layer from the top, and the other one from the bottom;
• c) At least two porous insulating layers made of an electrically nonconductive material, one of which covers the implant from the top, contacting the upper layer of the frame material, and the other one covers the implant from the bottom, contacting the lower layer of the frame material;
• wherein said layers are merged with each other in the form of a flat, multilayered inset for placing between the welded elements, and in that the electrically resistant layer has at least two electrical connections for connecting a source of electrical current.