The present invention provides a welding tool member for friction stir welding comprising a silicon nitride sintered body, wherein the silicon nitride sintered body includes an additive component other than silicon nitride in a content of 15% by mass or less, and the additive component includes three or more elements selected from Y, Al, Mg, Si, Ti, Hf, Mo and C. It is preferable that the content of the additive component is 3% by mass or more and 12.5% by mass or less. It is also preferable that the additive component includes four or more elements selected from Y, Al, Mg, Si, Ti, Hf, Mo and C. Due to above structure, there can be provided a welding tool member for friction stir welding having a high durability.

The present invention provides a welding tool member for friction stir welding comprising a silicon nitride sintered body, wherein the silicon nitride sintered body includes an additive component other than silicon nitride in a content of 15% by mass or less, and the additive component includes three or more elements selected from Y, Al, Mg, Si, Ti, Hf, Mo and C. It is preferable that the content of the additive component is 3% by mass or more and 12.5% by mass or less. It is also preferable that the additive component includes four or more elements selected from Y, Al, Mg, Si, Ti, Hf, Mo and C. Due to above structure, there can be provided a welding tool member for friction stir welding having a high durability.

The present disclosure arranges a pair of friction stir welding tools including probes and fixed shoulders at corner portions between a first workpiece and a second workpiece. The friction stir welding tools are arranged so that regions where the probes are embedded in the respective the corner portions and stirred are positioned symmetrically with respect to the second workpiece. With this arrangement of the friction stir welding tools, the corner portions are friction stir welded simultaneously.

In the present disclosure, friction stir welding tools having probes and stationary shoulders are disposed at corners between a first workpiece and a second workpiece. A welding device main body includes axially perpendicular movement units for moving spindle units, which hold the respective friction stir welding tools on a frame, in directions perpendicular to rotary shafts of probes, and axial movement units for moving the spindle units in directions parallel to the rotary shafts of the probes.

A metal composite and a metal joining method that are capable of suppressing an influence on joining strength of a friction stir welded section due to a tool hole formed when a tool is extracted, in the case in which two metals are joined through friction stir welding. In an overlapping section in an axial direction in which a first shaft and a second shaft overlap in the axial direction, an inscribed section in which the first shaft and the second shaft come in contact with each other and an non-inscribed section in which the first shaft and the second shaft do not come in contact with each other are formed. In the non-inscribed section, a plate thickness of the second shaft is decreased. Then, a starting point of a friction stir welded section is formed in the inscribed section, and an endpoint is formed in the non-inscribed section.

The invention relates to a method and to a device for welding together two joining partners by means of friction stir welding, which prevents the joining partners being contaminated by welding residue. The method comprises the following features: a welding head that can be integrated into any machine, said welding head being in the form of a spindle drive driven by a drive unit, comprising a mounting flange for securing the device assisting the welding process, and a clamping system for receiving a frustoconical-shaped tool having a welding and smoothing shoe for guiding a welding pin (11), a device (17) integrated into the welding and smoothing shoe for grinding the waste produced during the welding process, the waste produced during welding is then removed by means of one inlet channels for fluid arranged in the upper and/or lower area of the frustoconical-shaped tool for the fluid (20, 18) and a suction channel (19).

A method of sealing a hole in a wall of a hollow structure comprises providing a sealed chamber that is external to the structure and that is in fluid communication with an internal space of the structure via the hole. The structure may be a pipe-in-pipe structure and the internal space may be an annulus between outer and inner pipes. Fluid flows through the hole into or out of the chamber as the pressure and/or composition of fluid in the internal space is adjusted. Then, a plug is spun and friction-welded into the hole. The plug is inserted into the hole from within the chamber.

The invention relates to a method for producing tailored sheet-metal strips, in which at least one sheet-metal strip having a substantially planar surface is integrally connected along its longitudinal edge to at least one further web-shaped semifinished product made of metal, wherein the at least one further web-shaped semifinished product differs from the at least one sheet-metal strip in terms of at least one of its properties, and wherein the at least one sheet-metal strip and the at least one further web-shaped semifinished product are fed continuously to at least one joining station, characterized in that a web-shaped semifinished product having a three-dimensional structure, a hollow profile and/or a multiplicity of recesses and/or holes in succession along its longitudinal edge is used as the at least one further web-shaped semifinished product which is fed to the joining station. An apparatus for carrying out the method is furthermore claimed.

A method providing a first tubular workpiece having a first weld surface at an end thereof, and a second tubular workpiece having a second weld surface at an end thereof; aligning the workpieces on a common axis with the weld surfaces facing each other, rotating one workpiece about the axis relative to the other workpiece, and engaging the first and second weld surfaces such that the rotation raises the temperature at the weld surfaces to create a weld interface; and ceasing the rotation and allowing the weld interface to cool to weld the workpieces together at the interface. The first weld surface is an apex region of an annular projection at the end of the first workpiece, on a longitudinal section through the aligned workpieces the annular projection having a profile in which radially inner and outer side surfaces of the annular projection taper towards the apex region.

A method providing a first tubular workpiece having a first weld surface at an end thereof, and a second tubular workpiece having a second weld surface at an end thereof; aligning the workpieces on a common axis with the weld surfaces facing each other, rotating one workpiece about the axis relative to the other workpiece, and engaging the first and second weld surfaces such that the rotation raises the temperature at the weld surfaces to create a weld interface; and ceasing the rotation and allowing the weld interface to cool to weld the workpieces together at the interface. The first weld surface is an apex region of an annular projection at the end of the first workpiece, on a longitudinal section through the aligned workpieces the annular projection having a profile in which radially inner and outer side surfaces of the annular projection taper towards the apex region.