A method welds together two components of an internal combustion engine exhaust system, by resistance welding, to provide greater positioning freedom of two components welded together. A first component is provided with a welding area including an insertion opening edge surrounding an insertion opening. A second component is provided with a welding area including an insertion area to be inserted into the insertion opening. The insertion area is inserted into the insertion opening such that the insertion area is in contact with the first the entire insertion opening edge. An electrical voltage is applied to resistance weld the first component to the second component. The surface (28) of the insertion area is curved about two axes that are not parallel or is curved about an axis that is parallel to the surface of the insertion area, or/and an insertion surface of the insertion opening edge is located in one plane.

A joining outer diameter portion located at an axial-direction intermediate portion and fitting tapered outer diameter portions located on both axial-direction sides across the joining outer diameter portion are formed on an outer peripheral face portion of an inner metal member. A joining inner diameter portion corresponding to the joining outer diameter portion and having a smaller diameter than the joining outer diameter portion so as to overlap with the joining outer diameter portion, and fitting tapered inner diameter portions corresponding to the fitting tapered outer diameter portions are formed on an inner peripheral face portion of an outer metal member. The joining portions are joined by means of resistance heating generated by conducting electricity while they are pressurized in the axial direction. The fitting tapered portions are brought into a fitted state in association with the joining.

A joining outer diameter portion located at an axial-direction intermediate portion and fitting tapered outer diameter portions located on both axial-direction sides across the joining outer diameter portion are formed on an outer peripheral face portion of an inner metal member. A joining inner diameter portion corresponding to the joining outer diameter portion and having a smaller diameter than the joining outer diameter portion so as to overlap with the joining outer diameter portion, and fitting tapered inner diameter portions corresponding to the fitting tapered outer diameter portions are formed on an inner peripheral face portion of an outer metal member. The joining portions are joined by means of resistance heating generated by conducting electricity while they are pressurized in the axial direction. The fitting tapered portions are brought into a fitted state in association with the joining.

A method and apparatus for joining using friction and current, wherein the friction/current joining apparatus includes a friction device, a forging device, an electrical current source, and a programmable controller, as well as workpiece holders for the workpieces to be joined. The friction/current joining apparatus is controlled such that, in a contacting phase, the workpieces are initially moved along a process axis, and their mutually facing joining surfaces oriented transverse to a common process axis are brought into contact. In a grinding phase, while subjected to contact pressure by mutual relative movement, the joining surfaces, are ground together and made smooth. At the end of the grinding phase, the relative frictional movement is permanently stopped and, in a forging phase following the grinding phase, the workpieces are pressed together, plasticized, and joined while subjected to contact pressure on their contacting joining surfaces along the process axis, and subjected to conductive heating with electrical current.

A method of joining a high entropy alloy is provided. The method of joining a high entropy alloy includes the steps of: arranging specimens made of a high entropy alloy to be in contact with each other; and diffusion joining the specimens made of the high entropy alloy by simultaneously applying a compressive stress and a current to a joint of the specimens within a range in which the high entropy alloy does not melt.

A method of producing an endless metal ring by butting and welding ends of a steel plate includes a welding process in which, while the ends of the steel plate are heated at a temperature lower than a melting temperature, the ends are pressed against each other and welded by butt welding; and a heat treatment process in which heating is performed at an austenite transformation temperature or lower after the welding process.

A method of producing an endless metal ring by butting and welding ends of a steel plate includes a welding process in which, while the ends of the steel plate are heated at a temperature lower than a melting temperature, the ends are pressed against each other and welded by butt welding; and a heat treatment process in which heating is performed at an austenite transformation temperature or lower after the welding process.

In a method for manufacturing a shunt resistor, a resistor plate with a first side surface and a second side surface opposite to each other is provided. A first electrode plate and a second electrode plate are respectively pressed onto the first side surface and the second side surface, thereby forming a first connection surface between the first electrode plate and the resistor plate, and a second connection surface between the second electrode plate and the resistor plate. A first conductive module is placed on opposite ends of the first connection surface, and a second conductive module is placed on opposite ends of the second connection surface. Current is applied to the first and second connection surfaces via the first and second conductive modules respectively to weld the first electrode plate and the resistor plate, and to weld the second electrode plate and the resistor plate.

A method of resistance welding first and second parts formed of dissimilar materials includes disposing a first electrode on a side of the first part and a second electrode on a side of the second part. Grooves separated by raised portions are formed in a faying surface of the second part. Pressure is applied to the first and second parts via the set of electrodes, and the parts are heated via the electrodes to form a joint between the parts. A welded assembly includes metallic first and second parts welded together. The second part may have a faying surface defining a number of grooves separated by raised portions. The faying surfaces of the parts may be disposed at 10-80 degree angles with respect to a first part axis (and/or a welding pressure axis).

A method of resistance welding first and second parts formed of dissimilar materials includes disposing a first electrode on a side of the first part and a second electrode on a side of the second part. Grooves separated by raised portions are formed in a faying surface of the second part. Pressure is applied to the first and second parts via the set of electrodes, and the parts are heated via the electrodes to form a joint between the parts. A welded assembly includes metallic first and second parts welded together. The second part may have a faying surface defining a number of grooves separated by raised portions. The faying surfaces of the parts may be disposed at 10-80 degree angles with respect to a first part axis (and/or a welding pressure axis).