During friction stir spot welding, a controller executes a temperature holding control in which the controller controls a rotation driving unit so that a rotational speed of a tool is set to a value which is equal to or lower than a predetermined rotational speed at which a temperature of the tool is regarded as being equal to a welding temperature of lapped portions, and in which the controller controls a displacement driving unit to increase and reduce a welding pressure or plunge depth of the tool so that the temperature of the tool is held in a predetermined set range.

A friction stir welding device includes a friction stir welding tool equipped with a fixed shoulder on an outer periphery of a probe on a proximal end side, a main shaft positioning mechanism which relatively moves the friction stir welding tool with respect to a corner portion between workpieces a control device thereof, and a filler supply unit which supplies a filler to a stirring region in which the workpieces are stirred by the probe at the time of friction stir welding. When the probe is immersed into the corner portion to perform the friction stir welding, the fixed shoulder is maintained at a position separated by a gap from the surfaces of the workpieces with the control device.

The present invention discloses an electromagnetic pulse-aided friction stir lock welding processing device and method, which comprises an upper die body and a lower die body. The upper end of the lower die body is provided with a frustum-shaped settling tank. The lower end of the upper die body is provided with a tip inserted into the settling tank, an outer wall of the tip is fitted with an inner wall of the settling tank, a gap for placing parts to be processed is arranged between the upper die body and the lower die body.

An additive friction stir deposition machine and the method of using it. The friction stir deposition machine has a stationary tool with a fixed shoulder and an opening. The fixed shoulder is fixed from rotation with respect to a substate onto which feedstock material is deposited to build a layer. A guide tube holds the feedstock material and is rotatable within the stationary tool. The opening in the stationary shoulder circumscribes the open end of the guide tube. The feedstock material is co-rotatable with the guide tube and rotating the guide tube rotates with the feedstock.

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 method of performing friction stir spot welding of a plurality of steel plates, includes the steps of: friction stirring a spot welding portion of the plurality of steel plates by pressing a tool against the spot welding portion while rotating the tool, to plasticize the spot welding portion by friction heat; cooling the spot welding portion to cause martensitic transformation to occur in the spot welding portion, after the step of friction stirring the spot welding portion; and tempering the spot welding portion by the friction heat by re-pressing the tool against the spot welding portion while rotating the tool, after the step of cooling the spot welding portion.

A friction stir welding (FSW) tool includes a head, a tool holder and a body between the head and the tool holder and attached to the head and the tool holder. The body may include a plurality of cooling fins. An interior of the body may include a pressure sensor, a temperature sensor, a torque sensor, and a communication node in electronic communication with the pressure sensor, the temperature sensor, and the torque sensor. The communication node may be in Bluetooth communication with a computing device.

A friction stir spot joining apparatus for spot-joining a pair of plate members by friction stirring with a tool's pin portion includes an advancing and retracting driving device configured to advance and retract the tool to and from plate members, a rotationally driving device configured to rotate the tool, and control device configured to control advancing and retracting driving device and rotationally driving device. The control device executes joining control of pushing pin portion into plate members while the tool is rotated and causing pin portion to pressurize plate members, and executes heat dissipation control of reducing at least one of a rotation speed and a tool's pressurization force more than in the joining control while tool is rotated and pin portion is kept pushed into plate members after joining control and separating tool from plate members after the pin portion's surface temperature becomes less than an oxidation onset temperature.

A liquid cooling jacket is produced by forming a first butted portion where a step side face of a peripheral wall portion and an outer peripheral side face of a sealing body butt each other and a third butted portion where a step side face of a support pillar portion and a hole wall of the hole portion of the sealing body portion butt each other with a gap, and friction-stirring by inserting a tip side pin and a base side pin of a primary joining rotary tool that is rotating into the sealing body and moving the primary joining rotary tool along the third butted portion with an outer circumferential face of the tip side pin being kept off the step side face while having a second aluminum alloy of the sealing body flow into the gap.

A low-temperature joining method effectively suppresses reductions in the mechanical properties of a junction of various types of high-tensile steel or aluminum, and of a heat-affected zone; and produces a joint structure. A method for joining two metal materials by forming a joint interface in which the two metal materials face each other at a joint portion and plunge a rotation tool caused to rotate at a prescribed speed into the joint, the method for low-temperature joining of metal materials characterized in that the peripheral velocity of the outermost periphery of the rotation tool is set to 51 mm/s or less, whereby the recrystallization temperature inherent to the metal materials is reduced by introducing a large strain to the joint, and recrystallized grains are generated at the joint interface by setting the joining temperature to less than the recrystallization temperature inherent to the metal materials.