A welded assembly includes a first object or substrate, an interlayer, and a subsequent layer deposited on the interlayer. The interlayer is an ESD coating deposited on the first object, and the subsequent layer is deposited by ESD on the interlayer. The subsequent layer is made of a different materials from the substrate. Both the interlayer and the subsequent layer are subject to peening. In one case the interlayer has a lower either a lower thermal conductivity or a lower electrical conductivity than the substrate and the subsequent layer. In another example, the subsequent layer has a cermet content of greater than 40% by wt.

A welded assembly includes a first object or substrate, an interlayer, and a subsequent layer deposited on the interlayer. The interlayer is an ESD coating deposited on the first object, and the subsequent layer is deposited by ESD on the interlayer. The subsequent layer is made of a different materials from the substrate. Both the interlayer and the subsequent layer are subject to peening. In one case the interlayer has a lower either a lower thermal conductivity or a lower electrical conductivity than the substrate and the subsequent layer. In another example, the subsequent layer has a cermet content of greater than 40% by wt.

A workpiece of Ti or a Ti alloy includes a surface with a coating layer of titanium nitride. A region of the surface includes a connection zone of a Ti—N solid solution alloy. A second Ti or Ti alloy workpiece is contacted with the connection zone, and a weld joint is formed across the connection zone with a resistance welding process. The weld joint extends into the first Ti workpiece and the second Ti workpiece.

A workpiece of Ti or a Ti alloy includes a surface with a coating layer of titanium nitride. A region of the surface includes a connection zone of a Ti—N solid solution alloy. A second Ti or Ti alloy workpiece is contacted with the connection zone, and a weld joint is formed across the connection zone with a resistance welding process. The weld joint extends into the first Ti workpiece and the second Ti workpiece.

A system may include a current source; a first metal or alloy component with a first major surface electrically coupled to the current source; a second metal or alloy component with a second major surface electrically coupled in series to the first component and the current source via an external electrical conductor, where the first and second major surfaces are positioned adjacent to each other to define a joint region; a metal or alloy powder disposed in at least a portion of the joint region; and a controller. The controller may be configured to cause the current source to output an alternating current that conducts through the first component and the second component to induce magnetic eddy currents, magnetic hysteresis, or both within at least a portion of the metal or alloy powder disposed in at least the first portion of the joint region.

A method of joining a first piece of an automotive component that is made from a first material to a second piece of the automotive component that is made from a second material includes machining a fay surface onto each of the first and second pieces of the automotive component, cleaning the fay surfaces of each of the first and second pieces of the automotive component, placing a metal filler between the fay surfaces of the first and second pieces of the automotive component, holding the first and second pieces together with the metal filler positioned between the fay surfaces of the first and second pieces, and passing an electric current through the first piece, the metal filler and the second piece to melt the metal filler and weld the first piece to the second piece.

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 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 welded assembly includes a first component including an aluminum material, a second component including a stainless steel, and a third component including a steel material. An ultrasonic weld is formed between the first and second components to join them and form a stack. A sealant and/or adhesive may be applied to the stack. A resistance spot weld is used to join the third component to the stack to form the welded assembly. The resistance spot weld encompasses a portion of the first, second, and third components, and a portion of the ultrasonic weld. The resistance spot weld is completely encompassed in the welded assembly, and thus is sealed from electrolyte in a surrounding environment.

A welded assembly includes a first component including an aluminum material, a second component including a stainless steel, and a third component including a steel material. An ultrasonic weld is formed between the first and second components to join them and form a stack. A sealant and/or adhesive may be applied to the stack. A resistance spot weld is used to join the third component to the stack to form the welded assembly. The resistance spot weld encompasses a portion of the first, second, and third components, and a portion of the ultrasonic weld. The resistance spot weld is completely encompassed in the welded assembly, and thus is sealed from electrolyte in a surrounding environment.