A welded structure includes a first workpiece (11), a second workpiece (12), a bonded part (28) formed between the first workpiece and the second workpiece by plastically displaced materials of the first workpiece and the second workpiece, and a hooking portion (29) having a base end embedded in the second workpiece, and a tip end extending into the first workpiece, the hooking portion extending radially outwardly and upward along an outer periphery of the bonded part. A device for forming such a structure includes a clamp ring (18) which is provided with a central recess (25) in a part of a contact surface (24) thereof located around a through hole (19).

A quick connect refill friction stir spot welding tool includes a clamp having a first radially-projecting mounting tab configured for engaging a first mounting slot in a refill friction stir spot welding weld head. A friction sleeve is located coaxially within the clamp and has a second radially-projecting mounting tab configured for engaging a second mounting slot in the refill friction stir spot welding weld head. The second radially-projecting mounting tab is located higher along an axis of the tool than the first radially-projecting mounting tab, and radially inward thereof. A friction pin is located coaxially within the clamp and friction sleeve. The clamp and friction sleeve are attachable to and detachable from the refill friction stir spot welding weld head by rotations through less than 360 degrees.

A friction spot joining device configured to carry out friction spot joining of a pair of plates includes an advance-retreat drive configured to advance and retreat a tool to/from the plates a rotation drive configured to rotate the tool, and a controller configured to control the advance-retreat drive and the rotation drive. The controller executes a joining control in which the tool is caused to give pressure to the plates while the tool is rotated so that the tool is pushed into the plates, and a separating control in which the tool is separated from the plates when an integrated value (P=I.sub.D×ΔT) calculated using a current value (I.sub.D) of the rotation drive during the joining control and a driving period of time (ΔT) during the joining control is determined to be reached a target value.

A dissimilar metal welding method includes a preparing step and a working step. In the preparing step, a pin member is moved to a second metal material while being rotated, and a tool body is driven such that the tool body is moved in a direction away from the second metal material while being rotated. In the working step, a through-hole is formed in the second metal material by the pin member, and then a distal end of the pin member is dug into the first metal material to a predetermined depth position in the first metal material.

A friction stir welding apparatus and method maintains a depth of a welded part constant without varying a depth-direction position of a welding tool leading end part relative to welded members. A control device controls an operation of the friction stir welding apparatus, and a holder unit is connected to a swing mechanism unit via a revolving mechanism section, and a welding tool is held to the holder unit. The control device has a first welding mode in which friction stir welding is performed on the basis of a welding condition signal for deciding a welding condition of the welding tool, a swing control signal for controlling the swing mechanism unit, a first hold position decision signal, and a second welding mode in which friction stir welding is performed on the basis of the welding condition signal, the swing control signal, and a second hold position decision signal.

Solid-state additive and subtractive manufacturing processes, completely or partially performed by a solid-state manufacturing system, are disclosed. Solid-state deposition processes of different materials for printing 3D parts, coating, joining or repair are included as examples. Subtractive processing steps, such as machining, drilling, surface grooving, surface activation and others are discussed as well. In addition, other processes performed by other means are mentioned in making the final parts.

An object of the present invention is to provide a joining method by which metal members can be suitably joined to each other. The present invention is characterized by including a friction stirring process in which the first metal member, the second metal member, and the auxiliary member are joined to one another by moving the rotary tool along the inner corner portion in a state where the tip side pin which is being rotated is inserted into the inner corner portion, is in contact with the first metal member, the second metal member, and the auxiliary member, and an outer circumferential face of the base side pin is pressed against the auxiliary member.

A friction stir spot welding method performs friction stir spot welding of a pair of workpieces having a coating film formed on at least one welding surface by using a refill friction stir spot welding device including rotary tools. The method includes removing the coating film by plunging a distal end of the shoulder member into one workpiece up to a position closer to the surface than the welding surface, while rotating the shoulder member as a rotary tool around the axis, and rotating the shoulder member in a state in which the surface of one of the pair of workpieces, with the welding surfaces being overlaid on each other, is pressed by the end face of the clamp member and performing friction stir spot welding of the pair of workpieces after the coating film removal by using the pin member and the shoulder member as rotary tools.

A friction stir spot welder includes a controller configured to: drive a rotary actuator and an advancement/withdrawal actuator to cause a pin to press workpieces while rotating; after the pressing, drive the rotary actuator and the advancement/withdrawal actuator to cause the pin and a shoulder to press the workpieces while rotating; and after the pressing, drive the rotary actuator and the advancement/withdrawal actuator to cause the pin and/or the shoulder to plunge into a weld region of the workpieces while rotating and stir the weld region to weld the workpieces together.

A friction stir spot welder includes a pin, a shoulder, a rotary driver, an advance-retract driver, and circuitry. When a preset and predetermined first period of time has elapsed in a state where a speed of the rotating shoulder in an axial direction or a speed of the pin in the axial direction is a preset and predetermined first speed, the circuitry determines that the tip of the shoulder or the tip of the pin has reached a contact surface of a second workpiece which is in contact with a first workpiece.