Patent ID: 7348523

Claim:
A welding method for joining metal parts, said method comprising the steps of: (a) providing first and second metal work pieces, each work piece having a contact surface adapted for substantially mating engagement with the contact surface of the other work piece; (b) heating the work pieces so as to raise the temperature in a hot layer of metal adjacent to each contact surface to within the hot working range of the base metal of the work pieces; (c) bringing the contact surfaces into substantially mating contact while still in the hot working temperature range; (d) applying axial compressive load across the contact surfaces, said compressive load being sufficient to substantially prevent relative sliding between the contact surfaces in response to the imposition of transverse shear strain sufficient to induce plastic flow in the hot layers adjacent to the contact surfaces of the first and second work pieces; and (e) imposing transverse shear displacement between the work pieces, said shear displacement being sufficient to induce plastic shear strain within the hot layers to induce bonding of the work pieces in the interfacial region; such that the contact surfaces remain in substantially mating contact throughout the imposition of transverse shear displacement between the work pieces, without substantial relative transverse displacement between the contact surfaces.