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.

The friction stir welding head presented herein includes a head housing and an axle. The head housing extends from a top end to an open bottom end and defines a bore extending between the top end and the open bottom end. The axle that is coaxial with and rotatable within the bore. The axle is also laterally secured within the head housing and axially movable with respect to the head housing. Still further, the axle includes an engagement end that extends beyond the open bottom end of the head housing. The engagement end supports a friction stir welding tool that is configured to rotate with the axle to effectuate friction stir welding operations. The friction stir welding head may also include a load cell configured to generate load signals in response to axial movement of the axle.

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 welding apparatus including a controller that (A) operates a rotary driver and a tool driver such that a pin and a shoulder are brought into contact with a welded workpiece; (B) operates, after the (A), the rotary driver and the tool driver such that the pin separates from the welded workpiece; and (C) operates, after the (B), the rotary driver and the tool driver such that the pin advances toward the welded workpiece. The controller controls the tool driver such that pressing force applied to the welded workpiece from the pin and the shoulder in the (C) is smaller than that in the (B) and/or controls the rotary driver such that rotational frequencies of the pin and the shoulder in the (C) are lower than those in the (B).

A double-action friction stir joining system, which includes a double-action friction stir joining device, a cleaning mechanism having a dressing member, a robot, and a control device. The double-action friction stir joining device includes a first rotary driver configured to rotate a pin member and a shoulder member, and a tool driver configured to reciprocate the pin member and the shoulder member. The control device is adapted to (A) operate the tool driver so that the pin member is thrusted into the shoulder member, (B) operate the first rotary driver so that the shoulder member rotates, and (C) operate the robot so that the robot holds the double-action friction stir joining device and the dressing member contacts an inner circumferential surface of the shoulder member.

Provided are a friction stir welding apparatus and a friction stir welding method capable of highly accurate position control in a Z-axis direction (vertical direction) of a joining tool when a joint target member is subjected to friction stir welding by the friction stir welding apparatus. The friction stir welding apparatus includes a joining tool which consists of a shoulder portion and a probe portion and is inserted into a joint target member to rotate, a joining head which holds the joining tool, an apparatus body which holds the joining head, rotates the joining tool, and moves the joining tool, and a control device which controls an operation of the joining tool, in which the control device has a reference setting mode where a correction reference used for correction of misalignment in the Z-axis direction of the joining tool which occurs when the joint target member is joined by the joining tool is set in a stage before the joining tool is inserted into the joint target member, a joining mode where the joining tool is inserted into the joint target member and the joint target member is joined, and a correction mode where an amount of position fluctuation of a tip of the joining tool with respect to the correction reference which occurs when the joining tool joins the joint target member is measured and correction is performed when the amount of position fluctuation exceeds a predetermined threshold value.

Embodiments can include a self-reacting friction stir weld (“FSW”) tool. The device can be configured to be portable and produce full penetration welds in situ. The FSW tool can include a system that cuts out a portion of the structure surrounding a defective portion of the structure. A work-piece can be inserted within the removed portion and friction stir welded to the structure via the FSW tool. A superior repair as compared to merely welding the defect can be achieved by replacing a portion of the structure surrounding the defect as opposed to merely welding the defect (e.g., the crack). A controlled geometric shaped weld beam can be generated for the interface between the work-piece and the structure, which may led to a stronger, more reliable weld.

The present invention relates to methods to join at least first and second metallic components in which a pre-treatment is applied to one or more region(s) of at least one of the components to be welded together before welding takes place. The pre-treatment involves contacting at least a region of the first metallic component with a rotating and translating tool such that the rotating and translating contact locally heats, softens, and mixes successive portions of at least the region of the first metallic component. The first and second metallic components are placed together such that a joint is provided between at least the pre-treated region of the first metallic component and the second metallic component. At least the pre-treated region of the first metallic component is welded to the second metallic component along at least a portion of the joint.

A friction stir processing system can include a rotatable die assembly. The rotatable die assembly can include a die body and a plurality of die segments. The die body includes a die base and a die stem. The die stem extends axially from the die base, the die stem defines an extrusion cavity, and the die body is formed from a first material. The plurality of die stems are coupled to the die stem. The plurality of die segments are disposed around the extrusion cavity to collectively form a die surface opposite to the die base. The plurality of die segments are formed from a different material than the die body.