An object is to provide a friction stir welding method and apparatus that provide sufficient strength and good welding workability by advantageously eliminating plastic flow deficiency generated as a result of insufficient heating of workpieces.

In friction stir welding for steel sheets (3, 3) as workpieces, a pair of facing rotary tools (1, 15) are inserted into a non-welded part from both one surface side and the other surface side of the steel sheets (3, 3), the rotary tools move in a welding direction while rotating, and in addition, a preheating process for heating steel sheets (3, 3) is performed by heating means (5) provided in front of the rotary tools(1, 15). The configuration of the pair of facing rotary tools (1, 15) and the surface temperature, area, position, and so forth of a heated region in the preheating process are strictly controlled.

A method of forming a metal workpiece is disclosed herein. The method includes applying an electrical current through a feedstock material, applying a vertical axis force to the feedstock material; applying a rotational force to the feedstock material, and producing a metallic component from the feedstock material based on the electric current, the vertical axis force, and the rotational force.

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.

The invention belongs to the field of friction stir welding (FSW) quality prediction and relates to an intelligent prediction method for the tensile strength of FSW joints considering welding temperature and axial force. The invention uses a combination of experiment and theory. FSW experiment is carried out, the infrared thermal imager and force sensor are used to obtain the temperature of the feature points on the advancing side and retreating side of the outside of the shoulder of the weldment surface and the axial force during FSW process. The obtained data is used to train and test the one-dimensional convolutional neural network. The tensile strength prediction of friction stir welding is realized, which provided a reference for welding process control.

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.DT) calculated using a current value (I.sub.D) of the rotation drive during the joining control and a driving period of time (T) during the joining control is determined to be reached a target value.

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 friction stir welding apparatus includes a FSW tool that is held by a housing and welds to-be-welded members to each other by friction stir, and a gradual cooling device that gradually cools a weld site of the to-be-welded members welded by the FSW tool. The gradual cooling device is a contactless heat source that heats the weld site without coming into contact with the weld site. The contactless heat source is a high-frequency heat source.

A method of manufacturing a liquid-cooled jacket, includes a preparation step which includes placing a sealing body on a stepped portion to allow a step side surface and a sealing-body side surface of the sealing body to butt each other, and a primary joining step which includes allowing a primary joining rotary tool to move once around the sealing body, while moving the rotary tool along a butted portion formed in the preparation step, to carry out friction stir welding. The primary joining step includes employing the primary joining rotary tool provided with a stirring pin having a length dimension greater than a thickness dimension of the sealing body, and carrying out friction stirring with only the stirring pin being brought into contact with a jacket body and the sealing body.

A joining method includes abutting an end face of a first metal member in a plate shape having a projecting part on the end face on a rear face of a second metal member in a plate shape having a hole that is bored through the second metal member in a plate thickness direction and simultaneously inserting the projecting part into the hole. The method includes inserting a stirring pin of a rotary tool into an abutment portion of a wall of the hole and an outer peripheral surface of the projecting part from a front face side opposite to the rear face of the second metal member. The rotary tool is moved along the abutment portion to join the abutment portion by friction stirring. The abutment portion is joined together with only the stirring pin of the rotary tool being in contact with the first and second metal members.

Provided is a temperature measurement device for a rotating member of a processing device that grips a rotating member made from a metal and capable of rotating around a rotational axis, and moves in coordination with and coaxially rotates with the rotating member. This temperature measurement device is equipped with: an ideal temperature setting means for setting an ideal temperature while the rotating member is rotating; a temperature measurement means for measuring an actual temperature while the rotating member is rotating; and a detection means for detecting whether or not the difference between the actual temperature measured by the temperature measurement means and the ideal temperature set by the ideal temperature setting means exceeds a pre-set threshold at the time the actual temperature is measured.