A friction stir spot welding method according to one aspect of the present invention includes: performing a plunging process of moving a shoulder (28) toward a second workpiece (102) from a first workpiece (101) side while rotating a rotary tool to plunge the shoulder into the first and second workpieces; and performing a backfilling process of pushing stirred materials that have flowed into an inside of the shoulder in the plunging process out of the shoulder and backfilling a plunging hole with the stirred materials, the plunging hole being formed by the plunging of the shoulder. In the plunging process, the shoulder is plunged to a position that is shifted from a boundary between the first workpiece and the second workpiece to the second workpiece side by 1 mm or more, such that a component of a protective layer (104) is concentrated in a central portion of a stirred portion (105) when the backfilling process is completed.

A head piece and a welding tool, in particular an FSW tool, equipped therewith, and a welding method. The head piece has a through-opening for a plasticizing welding means, in particular a rotating welding pin. The head piece also has a profiled end face which faces the workpiece during welding and has end face regions of different heights and a sloping shoulder, which conducts the plasticized material of the workpiece and connects the end face regions.

A primary joining rotary tool F comprises a stirring pin F2including a circumferential face tapers to become thinner toward a tip portion of the stirring pin, a flat face F3 at the tip portion of the stirring pin F2 and a projecting portion F4 projecting from the flat face F3. Friction-stirring is performed in the primary joining process by inserting the stirring pin F2 that is rotating into an abutted portion J1 in a manner that only the stirring pin F2 is in contact with the base member 2 and the lid plate 5 with the flat face F3 being in contact with the base member 2 and the lid plate 5 and with a tip face F5 of the projecting portion F4 being in contact only with the base member 2.

A method for manufacturing a hydraulic housing for a braking system of a motor vehicle. A cylindrical or hollow-cylindrical first housing part and a second housing part of the hydraulic housing are integrally joined using friction welding. The method includes: a) attaching the first housing part to the second housing part, an end face of the first housing part being attached to the second housing part so that a shared contact area is created, b) plasticizing the two housing parts in the contact area and/or in a joint area adjoining the contact area by friction-based heat introduction, and c) compressing at least one housing part and/or pressing a friction welding tool against the housing parts so that material forming and/or material shearing is effectuated in the plasticized area of the two housing parts and both housing parts form an integral joint in the contact area and/or in the joint area.

The invention concerns a method for joining a metal component and a polymer component, and a structure comprising said components. In the method, an extrusion die plate with a through hole is placed between the metal component and the polymer component. A probe is rotated and plunged across the thickness of the metal component and eventually through said through hole of the extrusion die plate, thereby extruding a part of the metal component through said through hole of the extrusion die plate into the polymer component. The probe has a rotation axis having an offset to the centre of the through hole during the rotating and plunging action.

A first metal member (1) and a second metal member (2) are joined together using a rotary tool (F1D) comprising a base side pin (F3) and a tip side pin (F4), comprising an overlapping and abutting process of forming an overlapped portion (J1a), a top side abutted portion (J1b) and a back side abutted portion (J1c), and a friction stirring process of inserting the tip side pin (F4) that is rotating into the top side abutted portion (J1b) to join the top side abutted portion (J1b) and the overlapped portion (J1a) with a flat face (F5) vertical to a rotation axis of the rotary tool (F1D) being in contact with both the first metal member (1) and the second metal member (2) and with a tip face (f7) of a protruding portion (F6) protruding from the flat face (F5) being inserted deep over the overlapped portion (J1a).

The method comprises a primary joining process in which primary joining is performed by friction stirring by moving a rotary tool (F) once around a recessed part (13) along a first overlap part (H1) in a state where only a stirring pin (F2) of the rotary tool provided with the stirring pin is inserted in the first overlap part (H1) from a front surface (3b) of a sealing body (3) and is in contact with a jacket body (2) and the sealing body (3). In the primary joining process, the rotary tool (F), which is provided with a flat surface (F4) orthogonal to a rotational axis of the stirring pin (F2) and a projection (F5) projecting from the flat surface (F4) at a tip part of the stirring pin (F2), is employed, and the first overlap part (H1) is joined by bringing the flat surface (F4) into contact with only the sealing body (3) and inserting a tip end of the projection (F5) more deeply than the first overlap part (H1).

An ironing plate is attached to a friction stir welding apparatus in such a manner that the ironing plate surrounds an outer peripheral portion of a rotating tool and does not rotate together with the rotating tool, an inside diameter of a portion of the ironing plate into which the rotating tool is inserted is larger than the diameter of the rotating tool, and a material inflow path through which an excessive material of two metallic plates flows in is formed between the ironing plate and the rotating tool when the ironing plate is disposed to surround the outer peripheral portion of the rotating tool.

Described are methods for forming a friction stir weld between a steel piece and an aluminum piece, with specific examples of the steel piece and the aluminum piece being a cover and a base of an enclosure.

A method and apparatus for joining workpieces is described. The apparatus comprises a clamp configured to restrain a first workpiece against a second workpiece and an additive friction stir deposition (AFSD) machine comprising a spindle. The first workpiece is clamped to the second workpiece, and feedstock material is deposited, via rotation of the spindle, into an aperture extending through one or both of the first workpiece and the second workpiece. The deposited feedstock material forms a weld nugget that joins the first workpiece to the second workpiece.