WO2009127981A2

WO2009127981A2 - Object with a welded seam, method for producing an object and a friction stirring tool and a device for friction stirring

Info

Publication number: WO2009127981A2
Application number: PCT/IB2009/051142
Authority: WO
Inventors: Jürgen Silvanus
Original assignee: Eads Deutschland Gmbh
Priority date: 2008-04-15
Filing date: 2009-03-18
Publication date: 2009-10-22
Also published as: DE102008019062A1; DE102008019062B4; WO2009127981A3

Abstract

An object (19) made of at least one fiber-reinforced material is provided, comprising a welded seam (18) wherein a fiber (4) is disposed in the seam (18). The object (19) can be produced by introducing a rotationally driven pin-shaped protrusion (9) into a work piece area or into a connection area (12) of at least two adjacent work pieces (5, 6) under rotating motion, plasticizing the work piece area or the connection area (12) in at least one contact area between the rotating protrusion (9) and the work piece area or connection area (12), and introducing a fiber (4) into the plasticized area (17).

Description

description

Title of Invention: OBJECT OF A COMPANY

WELDING SEAMS, METHOD OF MANUFACTURING

ONE OBJECT AND ONE REFILL TOOL

AND A REFRESHING DEVICE

The invention relates to an article with a welded seam, a method for producing an article, in particular with a friction stir process, and a friction stir and a device for friction stir.

[2] Aerospace, railway and automotive applications require complex and large parts, traditionally made of several interconnected components. Joining fiber reinforced composite parts, such as by welding techniques, poses new challenges because the parts are made of at least two different materials, the matrix material and fibers embedded therein.

[3] Fiber reinforced composites such as fiber reinforced plastics and fiber reinforced metals and alloys have higher strength than the matrix material alone, as well as lower weight than conventional metallic structures. As a result, they are increasingly used in aerospace, railway and automotive engineering.

[4] It is therefore an object of the invention to provide a method of manufacturing an article which is capable of reliably bonding fiber-reinforced materials together and to provide an article of at least two interconnected fiber-reinforced materials. It is another object of the invention to provide a tool and a device with which this method can be performed.

[5] The problem is solved by the subject matter of the independent claims.

Further advantageous developments emerge from the respective dependent claims.

[6] According to the invention, an article is made of at least one fiber-reinforced

Material provided with a welded seam, wherein at least one fiber is arranged in the seam.

[7] When welding fiber-reinforced materials according to conventional

Procedure, only the matrix material is welded and melted. The fibers remain firm and unmelted. This leads to a seam, which consists only of the weld metal. The seam thus has no reinforcing fibers and consequently a smaller one Strength as the main body of the connected parts. Thus, under mechanical stress of the article, cracks in the seam may form or spread which may result in breakage of the seam and breakage of the article. This is avoided with the article according to the invention, since the seam has at least one fiber which reinforces the seam itself.

[8] In one embodiment, the fiber extends almost the entire length

Length of the seam. This has the advantage that the seam is homogeneously reinforced by the fiber, so that the reliability of the connection is increased.

[9] In another embodiment, the fiber has a helical or helical shape, in particular a helical shape. This shape has the advantage that the width and the length of the seam are reinforced by the fiber. The pitch and diameter of the helix (i.e., the helix) may be approximately the same over the entire length, or may vary.

[10] In a further embodiment, a plurality of fibers are arranged in the seam.

These fibers may be entangled or juxtaposed. The proportion of fibers in this way in the seam can be increased in order to further increase the strength of the seam. It is advantageous if the strength of the seam approximately corresponds to the strength of the non-welded parts, so that the strength of the object is spatially equal.

[11] The fibers introduced into the seam can be continuous fibers, but also short or long fibers.

[12] The article according to any one of these embodiments may be a component of an aircraft or a motor vehicle. In particular, in aircraft and motor vehicles cracks can be caused by continuous load of the components. Of course, this is to be avoided for safety reasons.

[13] The invention also provides a friction stir method which can be used to manufacture the article of any one of the preceding embodiments.

[14] Friction stir processing and friction stir welding (Friction

Stir Welding, FSW), two workpieces to be welded together are known to be brought into contact and held in this position. In the connecting region of the workpieces, a welding pin or a pin-shaped projection of a corresponding tool is inserted under rotary motion until a shoulder arranged above the welding pin on the tool rests on the surface of the workpieces. In this case, frictional heat is generated by the relative movement between the tool and workpieces, so that adjacent material regions assume a plasticized state in the connection region. The tool becomes in contact with the tool while the rotating welding pin is in contact with the tool Joining area is moved along the line connecting the workpieces forward, so that plasticized around the welding pin material and then consolidated. Before the material hardens completely, the welding pin is removed from the connection area or the workpieces.

[15] Parts made of fiber-reinforced materials, such as metal composites

(so-called MCCs) or suitable plastic materials can be welded together in this manner as a butt, lap or tee joint. The technique of friction friction is also used in the repair, processing and finishing of workpieces. Point connections can also be generated, whereby forward movement of the welding pin rotatingly in contact with the connection area or a translatory relative movement between the rotating welding pin and workpieces does not take place.

[16] According to the invention, the method comprises the following steps. A rotationally driven pin-shaped projection is inserted into a workpiece area or into a connecting area of at least two adjoining workpieces with rotating movement. The workpiece area or joint area is plasticized in at least one contact area between the rotating projection and the workpiece area or bonding area, and a fiber is introduced into the plasticized area.

[17] The introduced fiber may be an endless fiber which is preferably fed continuously. But it can also be introduced short or long fibers. In order to simplify the feeding of short fibers or long fibers, they may be embedded in a filler material (fiber-reinforced filler material) which is introduced into the plasticized region.

[18] The plasticized area is liquid so that a fiber can be introduced into this liquid area. This plasticized area has circulating currents caused by the rotation of the protrusion. An endless, solid fiber is captured by this circulating weld metal and positioned in the weld metal due to flow or flow. Consequently, after re-solidification of the plasticized area, the endless fiber having a flow-related shape is frozen in the seam between the workpieces.

[19] Due to these circulating currents, the endless fiber becomes helical, i. spiral or helical, arranged in the seam, wherein the projection along the connecting line is guided linearly. By combining the linear motion and the circulating currents in the weld metal, the pitch of the helix can be adjusted.

[20] The rotary-driven pin-shaped projection is typically part of a

A friction stir tool comprising a rotatably driven tool body. At the drive-remote end of the tool body is provided a shoulder from which extends in the direction away from the drive end of the tool body, the rotatable, pin-shaped projection having a smaller diameter than the shoulder. The shoulder and the pin-shaped projection are independently driven in rotation.

[21] The shoulder may have at least one passage opening which extends into

Direction drive remote end of the tool body extends. A fiber can be arranged in the passage opening and fed to the plasticized area of the workpiece or the connection area during the friction stir process.

[22] According to one embodiment of the method according to the invention, the shoulder is applied to the workpiece area or connecting area under at least temporary pressurization, wherein, while the projection is in contact with the workpiece area or connecting area, the speed of the shoulder has n = 0.

This method is advantageous when welding thick workpieces, especially plates with a thickness greater than 6 mm. It is important, in turn, that while the rotationally driven pin-shaped projection is in contact with the material or connection region, the shoulder does not perform a rotational movement, so that no additional frictional heat is generated at the workpiece surface by the shoulder. Thus, the heat input is significantly reduced by Reibwärmegenerierung on the surface of the workpieces, creating a so-called low-heat joining is possible. The additional heating on the workpiece surface is eliminated, so that here the heat load is low and at the same time a homogeneous heat load over the entire penetration depth of the welding pin is ensured. At the same time, the workpiece alloys soften less because the heat affected zone is less pronounced. Another positive effect is that residual stresses are reduced, so that the risk of delay is lower and an occurring delay is easier to handle.

[24] The surface of the workpieces pointing in the direction of the pin-shaped projection is, at the given moment, subjected to the required pressure by the action of the shoulder, which is advantageously reduced by a factor of 2 to 3 and is typically between 1 and 200 kN compared to conventional friction-stir methods. Thus, you can work with reduced process force, which in turn has a simplified system technology result. In addition, the process-related change in the residual stress states of the welded, repaired, machined or converted workpieces is reduced.

[25] The fact that no additional friction is caused by the non-rotating shoulder also causes the process to run at a higher speed or rotational speed. speed of the welding pin can be performed. The speed can be increased by a factor of 3 to 4 compared to conventional friction stir process and is typically between 200 and 5000 revolutions per minute.

[26] In another embodiment, the shoulder is applied to the workpiece area or

Affixed connection area under at least temporary pressurization, wherein, while the projection is in contact with the workpiece area or connection area, the rotational speed of the shoulder is smaller than the rotational speed of the projection. This embodiment makes it possible to set the shape of an endless fiber in the seam, since the shape is determined not only by the flow of the plasticized portion but also by the speed of rotation of the shoulder.

[27] According to another embodiment, the projection in the

Workpiece area or connecting area moved linearly, wherein the fiber is continuously introduced into the plasticized area. This embodiment is used to introduce a long or continuous fiber into a long seam.

[28] For joining two adjacent workpieces, the projection may be moved relative to the abutting workpieces along the joining line of the adjacent workpieces. Alternatively, the abutting workpieces are moved relative to the projection along the joining line of the abutting workpieces.

[29] The invention also provides a friction stir tool having a rotationally drivable

Tool body comprises, at its end remote from the drive, a shoulder is provided, extending from the end facing away from the drive tool body rotatable, pin-shaped projection having a smaller diameter than the shoulder, wherein the shoulder and the pin-shaped projection are independently driven to rotate. According to the invention, the shoulder has at least one passage opening which extends in the direction away from the drive end of the tool body.

[30] A fiber may be disposed in the through hole and during the

Friction stir process in the plasticized region of the workpiece or the connection area are introduced. This arrangement has the advantage that the through-hole and the position of insertion of the fiber are as close as possible to the plasticized region. This allows for reliable insertion of the fiber into the seam.

[31] In a further embodiment, the passage opening widens in

Direction drive away surface of the shoulder. The fiber can be introduced through this passage opening directly above the workpiece in the plasticized area.

[32] The passage opening may be substantially perpendicular to one in the direction extend away from the drive surface of the shoulder. This has the advantage that the guide length of the fiber arranged in the shoulder is small.

[33] In another embodiment, the passage opening extends from a surface of the shoulder facing away from the drive to a surface of the shoulder which is remote from the projection. This arrangement has the advantage that the fiber source is arranged next to the tool body. This can simplify the structure of the arrangement.

[34] In a further embodiment, the shoulder is designed such that it has a rotational speed n = 0 during rotation of the pin-shaped projection. The central idea here is to design a friction stir tool in such a way that the welding pin and shoulder are decoupled from each other, so that upon rotation of the welding pin the shoulder just does not perform any rotational movement, but with respect to the workpieces to be joined or machined in the sense of rotation or is fixed. However, this does not exclude a displacement of the shoulder in the axial direction of the tool. In this case, the shoulder defines a region of the friction stir tool having a larger diameter than the welding pin and ensures that, starting from a certain penetration depth of the welding pin, the shoulder rests positively and positively on the workpiece surface in order to apply the required compressive force to the workpiece surface and escape of plasticized material to prevent.

[35] According to a preferred embodiment, the shoulder is by means of a suitable

Storage of the tool body or of the pin-shaped projection driving spindle rotation freed and thus contributes deliberately no additional frictional heat to the welding process, but is able to transmit the necessary vertical force on the workpieces to be joined. The shoulder is preferably mounted on the tool body by means of rolling bearings. Such bearings are for example ball, barrel, needle roller bearings or the like. Alternatively, hydrostatic or hydrodynamic plain bearings can be used to support the shoulder, to name but a few more examples.

[36] Advantageously, the shoulder is formed as a molded part, which on the in

Direction pin-shaped projection facing side of the bearing is arranged. The molded part, which is for example a sheet-metal element (eg a steel sheet with a thickness of typically 2 to 5 mm) or a cast components, can for this purpose be provided with a bore for passing the pin-shaped projection, and from below (ie from the direction of the pin-shaped Projection) are pushed onto the bearing. It is important to ensure that the area between the molded part and the pin-shaped projection is formed as tight as possible in order to prevent escape of plasticized material in the axial direction of the friction stir tool. [37] Alternatively, an arrangement with a molded part without storage can be used.

[38] Furthermore, it is advantageous that the edge region of the molded part is angled in such a way that it at least partially surrounds the bearing. It is particularly advantageous if the molded part at least partially surrounds both the side regions of the bearing and the surface of the bearing pointing in the direction of the tool drive. In this way, it is ensured that when removing the tool or the pin-shaped projection from the workpiece or connecting region, the shoulder does not slip or move in the axial direction of the tool. At the same time it is counteracted by adhesion of the shoulder to the surface of the welded or machined workpieces.

[39] The molding is expediently provided with a friction-reducing material, at least on its side pointing in the direction of the projection. For this purpose, for example, the material "CC Aluspeed <(RTM)>" from Cemecon can be applied as a coating. As a result, the friction between the molded part and the workpiece surface is additionally reduced, which corresponds to the function of a sliding shoe.

[40] According to an alternative embodiment, the shoulder is moved through in the direction

Projecting side of a corresponding arranged on the tool body bearing (such as sliding or rolling) formed. This represents a particularly simple embodiment, since an additional element (for example, the molded part) can be dispensed with.

[41] Also in this alternative embodiment, it is expedient in the direction

To coat protruding side of the bearing with a friction-reducing material of the aforementioned type, in turn, to reduce the friction between the shoulder and the workpiece surface.

[42] Conveniently, the pin-shaped projection is integral with the

Tool body formed, resulting in a very simple structure and the system technology for driving the tool or the pin-shaped projection is extremely simple, since essentially only one spindle to be driven is required. The friction stir tool is usually rotationally symmetrical.

[43] The friction stir tool according to the invention ensures that the work piece material close to the shoulder is not overheated. Thus, when welding workpieces, it is ensured that the root area of the welded joint, which otherwise tends to be cold-welded, is welded securely and with high quality, thanks to the higher selectable welding pin speed compared to known friction stir welding tools. It is achieved a uniform temperature distribution over the entire cross section of the workpieces, which is a prerequisite for a high quality welded joint is.

In addition, the tool according to the invention in an analogous manner to the

Repair, machining and finishing of workpieces are used.

[45] The invention also provides a device for friction stir comprising

Friction stir tool according to one of the preceding embodiments. The protrusion is insertable into a workpiece area or a connecting area of at least two workpieces to be connected with rotating movement, so that when it is rotated in contact with the workpiece area or connecting area, the protrusion plasticizes and plastifies this material at least in the contact area. The apparatus further comprises a fiber source, wherein fibers may be introduced into the plasticized material via the passage opening. The fibers can be supplied for example in the form of continuous, short or long fibers.

[46] The device may further comprise drive means with which the device can be guided linearly while the drive of the projection is rotating. Alternatively, the workpieces are moved linearly relative to the device, in particular the projection.

[47] In one embodiment, the shoulder on the workpieces outside the

Contact area between the projection and the workpiece area or connection area can be applied. The shoulder can thus be driven perpendicular to the workpieces, thus causing a pressurization of the workpiece.

[48] The friction stir tool and the apparatus of any one of the preceding

Embodiments can be used for welding fiber-reinforced plastics, fiber-reinforced metals or fiber-reinforced alloys, or for welding two adjoining workpieces made of fiber-reinforced plastic, fiber-reinforced metal or a fiber-reinforced alloy.

[49] The invention will now be explained in more detail with reference to the drawings.

[50] FIG. 1 shows a cross section of a device for friction stir of a fiber reinforced material with a friction stir tool and a fiber source, FIG.

[51] Fig. 2 is a plan view of the device according to Fig. 1, and

[52] Fig. 3 shows a perspective view of a component of two workpieces, which are welded together with the apparatus of FIG. 1.

[53] Fig. 1 shows a cross section of a device 1 for friction stir. The device

1 has a friction stir tool 2, a fiber source 3, for example a coil with an endless fiber 4, and a drive, not shown. 1 also shows the use of the device 1 for joining workpieces, which in this exemplary embodiment are two fiber-reinforced joining parts 5, 6. [54] The fiber-reinforced joining parts 5, 6 have a matrix material made of thermoplastic, for example polypropylene, in which endless fibers, for example carbon fibers, are arranged. The joining parts 5, 6 are arranged adjacent to one another in FIG. 1 in butt joint connection. Of course, the joining parts 5, 6, even overlapping or in T-joint connection are welded together, which is not described in detail below, but mutatis mutandis from the following description, so that the invention is not limited to the embodiments described below is.

[55] The friction stir tool 2 is rotationally symmetrical and comprises a

Tool body 7, which at the top, i. is formed at the drive-facing end, typically in the form of a bearing shaft, to be received in a tool holder of a drive device (e.g., rotary motor) not shown in FIG. At the end of the tool body 7 facing away from the drive, a shoulder 8 is provided, from which a rotatable, pin-shaped projection 9 or welding pin 9 extends in the direction of the end of the tool body 7 facing away from the drive. The pin-shaped projection 9 has a smaller diameter than the shoulder 8.

In the embodiment shown in Fig. 1, the pin-shaped projection 9 is formed integrally with the tool body 7, which is a particularly simple arrangement, since only a drive mechanism for rotating the tool body 7 and thus the pin-shaped projection 9 is required. The axis of rotation of the friction stir welding tool 1 is shown in FIG. 1 by the dot-dash line.

[57] Alternatively, the tool body 7 may be a mechanism (not shown) for

Receiving the welding pin 9, so that a replacement or displacement of the welding pin 9 along the axis of rotation (i.e., in the axial direction) is easily possible.

Regardless of whether the pin-shaped projection 9 integral with the

Tool body 7 or interchangeable, the shoulder 8 is preferably arranged by means of roller bearings 10 on the tool body 7. Such bearings 10 may be, for example, ball, barrel or needle roller bearings. By the bearing of the shoulder 8 with the rolling bearings ensures that the shoulder 8 and the welding pin 9 and the tool body 7 are independently driven. In a preferred embodiment, upon rotation of the welding pin 9 or of the tool body 7, the shoulder 8 does not rotate and thus has a rotational speed n = 0. In this way, the shoulder 8 is freed or decoupled from the rotation of the welding pin 9 driving.

[59] Instead of rolling bearing bearings, hydrostatic or hydrodynamic Namische plain bearings are used. However, the function of storage is the same. Alternative can be dispensed with a storage.

[60] In Fig. 1, the shoulder 8 is formed as a molded part. Such moldings may be sheet-like elements (eg steel sheets), castings or the like, which are advantageously provided with a friction-reducing coating on their side facing the welding pin 9 in order to further increase the friction between the shoulder 8 and the surface of the workpieces 5, 6 to diminish. For this purpose, for example, the material CC Aluspeed <(RTM)> Cemecon can be used. The edge region of the molded part can be angled pointing in the axial direction of the friction stir tool 2 and bear against the side regions of the lower bearing shell. In order to prevent the shoulder 8 from sticking to the welded fiber-reinforced joining parts 5, 6 or displacing the shoulder 8 in the axial direction, the shaped part can also surround the rolling bearing 10 up to its side facing the drive-facing end.

In the design of the molded part, care must be taken to ensure a good seal between the shoulder 8 and the welding pin 9, so that the plasticized material does not act in the axial direction, i.e. in the axial direction. in the direction of the drive-facing end of the tool body 7, can escape. This can be achieved for example by a bore arranged in the molding, which is adapted to the diameter of the welding pin 9. The molded part can be pushed onto the bearing 10, for example, from below via the welding pin 9.

[62] The shoulder 8 further has a passage opening 11 which extends in the direction away from the drive end of the tool body 7, and which is arranged in this embodiment approximately perpendicular to the drive-facing surface of the shoulder 8. The passage opening 11 is arranged in the shoulder 8 next to the welding pin 9 (see also FIG. 2). The endless fiber 4 is supplied from the fiber source 3 through the through-hole 11, so that the end of the fiber 4 is disposed below the end of the tool body 7 remote from the drive.

For welding the adjoining fiber-reinforced joining parts 5, 6, the pin-shaped projection 9 is known under rotating movement in the connecting portion 12 of the joint parts 5, 6 introduced and moved along the connecting line 13 of the joining parts 5, 6 forward. This forward movement is shown by the arrow 14 in FIG. The rotation of the projection 9 is shown by the arrow 15 in Figures 1 and 2.

[64] The rotating movement of the welding pin 9 on the surface of the fiber reinforced

Joining parts 5, 6 generates frictional heat due to the relative movement between tool and workpieces. This frictional heat leads to a plasticization of the adjacent plates in the contact area, so that the rotating welding pin 9 in the Connection area can be introduced. The plasticized material 17 is formed on the connecting line and flows circulating around the welding pin 9 around. This is shown by the arrows 16 in FIG. The currents flow in horizontal circles as well as in vertical circles. The fiber 4 is introduced into this plasticized material 17, wherein the fiber 4 by means of the excited by the welding pin 9 material flow of the matrix material of the joining parts 5, 6 detected by the circulating weld metal and flow-dependent or flow-dependent positioned in the weld metal.

The welding pin 9, while the rotating welding pin 9 in contact with the

Connecting portion 12 is linearly along the connecting line 13 between the two plates 5, 6 moves. The connecting region 12 is plastified in the forward direction and the endless fiber 4 is fed continuously to the plasticized region 17. In the reverse direction, the connecting region 12 solidifies again, so that the fiber 4 is frozen in the welded seam 18. Thus, a fiber reinforced material component 19 is provided in which the seam 18 and the workpieces 5, 6 are fiber reinforced. Due to the flow-dependent or flow-dependent positioning of the fiber 4 in the weld metal, a seam 18 can be provided, in which the fiber 4 in the seam 18 has a helical shape. This is shown in FIG.

The object 19 thus has two fiber-reinforced joining parts 5, 6, which are connected to one another via a welded seam 18. An endless fiber 4 having a helical shape is disposed in the seam 18 and extends along the longitudinal direction of the seam 18. The article 19 comprises a fiber reinforced seam 18 and fiber reinforced adherends 5, 6 and may be used as a component for an aircraft or a motor vehicle ,

[67] The method according to the invention provides for solid-state welding of endless-fiber-reinforced metals and plastics, in which at the same time targeted fiber positioning in the weld metal is achieved. This has the advantage that not only the matrix materials are welded together. In conventional friction stir welding continuous fiber reinforced materials, the fibers in the contact area between the welding pin 9 and the joining parts 5, 6 are severed, so that the strength of the compound comes only from the organic or metallic matrix material. This strength is significantly lower than that of the fiber-reinforced material. This is avoided by the inventive targeted positioning of an additional fiber in the welded seam, so that the strength of the seam is increased and the welded component is more reliable and resilient.

[68] Preferably, the shoulder 8 does not rotate while the welding pin 9 rotates.

Consequently, no additional frictional heat is generated by the shoulder 8, but it is only ensured that the required pressure is exerted on the material to be plasticized in the connection area by the shoulder 8 at a given time. Due to the fact that the shoulder 8 is "fixed" in a rotational sense during the friction stir welding process, both a higher rotational speed of the welding pin 9 and a reduction in the process force imparted by the shoulder 8 are possible, the latter leading in particular to a simplification of the system technology. The former in turn has the consequence that a uniform temperature distribution over the entire thickness or the entire cross section of the joining parts 5, 6 is ensured during the friction stir welding process, so that they can be welded reliably and with high quality. The friction heat generation otherwise caused by the shoulder 8 on the surface of the joining parts 5, 6 is significantly reduced, whereby overheating on the surface is effectively prevented.

[69] According to an alternative embodiment of the friction stir tool according to the invention

2 can be dispensed with the molding. Then the side of the bearing 10 pointing in the direction of the welding pin 9 serves as a shoulder. This is due to the reduced components a particularly simple embodiment. The function and operation of this alternative shoulder is the same as in the above-described, formed as a molded part shoulder. 8

[70] Another alternative design of the molding allows to dispense with the bearing.

[71] list of reference numerals

[72] 1 device

[73] 2 friction stir tool

[74] 3 fiber source

[75] 4 fiber

[76] 5 first workpiece

[77] 6 second workpiece

[78] 7 tool body

[79] 8 shoulder

[80] 9 welding pin

[81] 10 Storage

[82] 11 passage opening

[83] 12 connection area

[84] 13 connecting line

[85] 14 forward movement

[86] 15 Rotation of the welding pin

[87] 16 flow of the weld metal [88] 17 plasticized substance

[89] 18 welded seam

[90] 19 Item with welded seam

Claims

[Claim 1] Article (19) made of at least one fiber-reinforced material with a welded seam (18), characterized in that a fiber (4) is arranged in the seam (18).

[Claim 2] Article (19) according to claim 1, characterized in that the fiber (4) extends over almost the entire length of the seam.

[Claim 3] Article (19) according to claim 1 or claim 2, characterized in that the fiber (4) has a helical shape.

[Claim 4] Article (19) according to one of Claims 1 to 3, characterized in that a plurality of fibers (4) are arranged in the seam (18).

[Claim 5] Article (19) according to claim 4, characterized in that the fibers (4) are entangled with each other.

[Claim 6] Article (19) according to one of Claims 1 to 5, characterized in that the object (19) is a component of an aircraft or of a motor vehicle.

[Claim 7] Method of friction stirring, which comprises the following steps:

Inserting a rotationally driven pin-shaped projection (9) into a workpiece area or into a connecting area (12) of at least two abutting workpieces (5, 6) while rotating,

Plasticizing the workpiece area or the connecting area (12) in at least one contact area (17) between the rotating projection (9) and the workpiece area or connecting area (12), and

- Introducing a fiber (4) in the plasticized area (17).

[Claim 8] A method according to claim 7, characterized in that a shoulder (8) is applied to the workpiece area or connecting area (12) under at least temporary pressurization, while the projection (9) is in contact with the workpiece area or connecting area Speed of the shoulder (8) n = 0.

[Claim 9] A method according to claim 7, characterized in that a shoulder (8) is applied to the workpiece area or connecting area under at least temporary pressurization, wherein during the projection (9) in contact with the workpiece area or Connection range is, the speed of the shoulder (8) is greater than 0 and less than the rotational speed of the projection (9).

[Claim 10] Method according to one of claims 7 to 9, characterized in that the projection (9) in the workpiece region or connecting region (12) is moved linearly, wherein the fiber (4) is continuously introduced into the plasticized region (17) ,

[Claim 11] Method according to one of Claims 7 to 10, characterized in that the projection (9) is moved relative to the adjoining workpieces (5, 6) along the connecting line (13) of the adjacent workpieces (5, 6).

[Claim 12] Method according to one of claims 7 to 11, characterized in that the adjacent workpieces (5, 6) relative to the projection (9) along the connecting line (13) of the adjacent workpieces (5, 6) are moved.

[Claim 13] friction stir tool (2), comprising a rotatably driven tool body (7) at its end remote from the drive a shoulder (8) is provided, from which in the direction away from the drive end of the tool body (7), a rotatable, pin-shaped projection (9) , which has a smaller diameter than the shoulder (8), wherein the shoulder (8) and the pin-shaped projection (9) are independently driven to rotate, characterized in that the shoulder (8) has at least one passage opening (11) extends in the direction away from the drive end of the tool body (7).

[Claim 14] friction stir tool (2) according to claim 13, characterized in that the shoulder (8) is designed such that it has a rotational speed n = 0 upon rotation of the pin-shaped projection (9).

[Claim 15] friction stir tool (2) according to claim 13 or claim 14, characterized in that the shoulder (8) by means of sliding or rolling bearing (10) is mounted on the tool body (7).

[Claim 16] friction stir tool (2) according to claim 15, characterized in that the shoulder (8) is a molded part which is arranged on the in the direction of projection (9) facing side of the sliding or rolling bearing (10).

[Claim 17] friction stir tool (2) according to claim 16, characterized in that an edge portion of the molding is angled such that it at least partially surrounds the sliding or rolling bearing (10).

[Claim 18] friction stir tool (2) according to claim 16 or claim 17, characterized in that the molded part is provided with a friction-reducing material at least on its side pointing in the direction of the projection (9).

[Claim 19] A friction stir tool (2) according to claim 13 or claim 14, characterized in that on the tool body (7) a sliding or rolling bearing (10) is arranged, whose at least in the direction of protrusion (9) side facing the shoulder (8 ).

[Claim 20] friction stir tool (2) according to claim 19, characterized in that in the direction of projection (9) facing side of the sliding or rolling bearing (10) is provided with a friction-reducing material.

[Claim 21] Friction stir tool (2) according to one of claims 13 to 20, characterized in that the pin-shaped projection (9) is formed integrally with the tool body (7).

[Claim 22] friction stir tool (2) according to one of claims 13 to 21, characterized in that the tool (2) is rotationally symmetrical.

[Claim 23] Friction stir tool (2) according to one of Claims 13 to 22, characterized in that the passage opening (11) widens in the direction of the drive-side-facing surface of the shoulder (8).

[Claim 24] Friction stir tool (2) according to one of claims 13 to 23, characterized in that the passage opening (11) extends substantially perpendicular to the drive-facing away from the surface of the shoulder (8).

[Claim 25] Friction stir tool (2) according to one of claims 13 to 23, characterized in that the passage opening (11) from the drive-facing away in the direction of the surface of the shoulder (8) up to the projection (9) facing away from the surface of the shoulder (8) extends.

[Claim 26] A device (1) for friction stir comprising a friction stir tool (2) according to any one of claims 13 to 25, wherein the projection (9) into a workpiece region or a connection region (12) of at least two to be connected workpieces (5, 6 ) can be inserted under rotating movement, so that when it is rotated in contact with the workpiece region or connecting region (12) the projection (9) produces this plasticized and plasticized material (17) at least in the contact region, characterized in that the device (1) furthermore a fiber source (3), and that a fiber (4) via the passage opening (11) in the shoulder (8) in the plasticized material (17) is insertable.

[Claim 27] Device (1) according to claim 26, characterized in that the device (1) further comprises drive means with which the device (1) can be linearly guided by rotating the projection (9).

Device according to claim 26 or claim 27, characterized in that the shoulder (8) can be applied to the workpieces (5, 6) outside the contact region between the projection (9) and the workpiece region or connecting region (12) is.

Claim 29 Use of the friction stir tool (2) according to one of claims 13 to 25 for welding fiber-reinforced plastics, fiber-reinforced metals or fiber-reinforced alloys.

[Claim 30] Use of the friction stir tool (2) according to one of claims 13 to 25 for welding two adjoining workpieces made of fiber-reinforced plastic, fiber-reinforced metal or fiber-reinforced alloys.

Claim 31 Use of the device (1) according to one of claims 26 to 28 for welding fiber-reinforced plastics, fiber-reinforced metals or fiber-reinforced alloys.

[Claim 32] Use of the device (1) according to one of claims 26 to 28 for welding two adjoining workpieces made of fiber-reinforced plastic, fiber-reinforced metal or fiber-reinforced alloys.