A method for operating a double-action friction stir welding device including a welding tool having a pin member and a shoulder member, a projection/retraction mechanism for causing the pin member to project/retract relative to the shoulder member, a rotation mechanism for rotating a welding tool, and an advancing/retracting mechanism for advancing/retracting the welding tool, the method including cleaning at least one of the outer circumferential surface of the pin member and the inner circumferential surface of a through hole of the shoulder member on the basis of the level of an adhesion parameter correlated with the degree of adhesion of the material of a welding object, caused by friction stir welding, on the outer circumferential surface of the pin member and the inner circumferential surface of the through hole of the shoulder member.

The present invention relates to a friction stir welding head including a central pin shaft, a peripheral shoulder part, a shaft for driving in rotation the part and the shaft about the axis, the shaft being integral in rotation with the part and being free in translation with respect to the part along the axis, the head including an external interface part intended to be secured to a rotary spindle of the machine, a device for transmitting the rotation of the shaft about the axis of rotation from the part and a device for driving in translation the shaft along the axis from the motor during the rotation of the shaft and of the part.

A method of friction stir processing (FSP) includes contacting a first workpiece with a FSP tool, where the first workpiece is a low-melting temperature metal or alloy and the FSP tool is a single-body FSP tool having a diamond working surface. The method also includes rotating the FSP tool in contact with the first workpiece at an interface and generating thermal energy at the interface to heat the first workpiece. The method further includes conducting thermal energy away from the interface with the FSP tool, and friction stirring the first workpiece at a temperature of the FSP tool below 800° C.

Provided is a method and tool for butt welding a first material piece of metal to a second material piece of metal at opposed longitudinal edges. The second material piece has a greater material thickness than the first material piece. The first material piece has a higher tensile strength and/or a higher inching temperature and/or a higher yield strength and/or a higher modulus of elasticity than the second material piece. A thickened longitudinal edge is provided at the first material piece. The thickening of the longitudinal edge is at least partly produced by at least simple folding, beading or winding of the first material piece or at least partly by folding the first material piece at its edge. The two material pieces are friction-stir welded at their front along the opposed longitudinal edges.

A system includes a tool configured to be positioned proximate to respective welding surface of separate components. The tool includes a tool head and an actuator configured to drive rotation of the tool head. The tool also includes a controller having a memory operatively coupled to a processor. The processor is configured to provide a command signal to the actuator to apply a pulsed torque to drive rotation of the tool head to facilitate joining the respective welding surfaces of the separate components to one another.

A friction stir spot welding apparatus according to the present invention includes: a rotary tool; and a perpendicular-to-plane detector, which detects whether or not the rotary tool is positioned to be in a perpendicular-to-plane state relative to a joining target portion of workpieces. The perpendicular-to-plane detector measures distances to at least three measurement positions set around the joining target portion by means of, for example, position sensors. The measurement positions are set to be positioned at the vertices of a polygon on a reference plane to which forward and backward movement directions of the rotary tool are normal. The perpendicular-to-plane detector detects that the rotary tool is positioned to be in the perpendicular-to-plane state relative to the joining target portion of the workpieces if all the distances to the measurement positions are equal to each other.

A machine tool and a control method for the machine tool, which determine the degree of misalignment during friction joint, are provided. The machine tool (an automatic lathe 1) includes: a first spindle 10 rotatably holding a first workpiece (a workpiece W1); a second spindle 20 arranged to face the first spindle and rotatably holding a second workpiece (a remaining workpiece W2); and a controller 40a, while rotating at least one of the first workpiece or the second workpiece, relatively moving the first spindle and the second spindle so as to get closer to each other and pushing a rear end portion of the second workpiece against a front end portion of the first workpiece to frictionally join the first and second workpieces. The controller has a misalignment amount detector detecting a misalignment amount s of the second workpiece with respect to the first workpiece during the friction joint.

A friction stir spot welding apparatus includes a pin member, a shoulder member, a rotation driver, a forward/backward movement driver, and a controller. The controller controls the forward/backward movement driver, such that the pin member and/or the shoulder member press workpieces before a clamp member presses the workpieces, and then controls the rotation driver and the forward/backward movement driver, such that the pin member and the shoulder member stir the workpieces.

The presently disclosed technology includes a friction stir welding apparatus comprising a frame, a moving platform and a parallel mechanism composed of three branch mechanisms, wherein a first branch mechanism comprises a first sliding pair, a first revolute pair, a telescopic rod and a first spherical pair connected in sequence. A second branch mechanism and a third branch mechanism both comprise a third sliding pair, a second revolute pair, a third linkage and a second spherical pair connected in sequence. The friction stir welding apparatus has high stiffness, low inertia, high dynamic performance and high accuracy, which can achieve precision welding with high requirements on processing quality and accuracy for jointing annular seams of large-scale rocket fuel storage tank barrels in the aviation field, for example. The presently disclosed technology also includes a corresponding friction stir welding system.

A friction stir welding tool comprises a cylindrical shank, a shoulder portion disposed at a distal end of the shank, a pin extending from the shoulder, a cutting insert mounted within a concave portion at the distal end of the shank, and a scribe cutter mounted at a distal end of the cutting insert. The cutting insert extends distally through a channel in the pine, and the scribe cutter extends from a distal end surface of the pin in an offset position. The distal end surface of the pin is perpendicular to a longitudinal axis of the shank.