DE102008023495A1 - Component for an aircraft structure, method for producing a component for an aircraft structure and use of the component as a crack stopper - Google Patents

Abstract

A component suitable as a crack stopper or Doppler for an aircraft structure has at least one first cover layer (3) forming a first skin surface (5) of the component (1), wherein the first cover layer (3) comprises substantially aluminum or an aluminum alloy, and Base body (2) having titanium or a titanium alloy. To produce the component (1), a first workpiece made of titanium or a titanium alloy is provided and a second workpiece made of aluminum or an aluminum alloy. The first workpiece is connected to the second workpiece by plating.

Description

The Invention relates to a component for an aircraft structure, which is used for example as a crack stopper. It concerns Furthermore, a method for producing such a component.

Currently are used in highly polluted areas, so-called "hot spots", an aircraft structure crack stopper made of titanium or a titanium alloy used. Crackstops are also used at joints between stringer and frame or for reinforcement of joints as a doppler or strut. They demonstrably improve the strength and the structural stability of the aircraft structure and are both in the area of the upper shell and the lower shell of the outer skin used. In laboratory experiments showed with crack stoppers or Dopplers Titanium materials associated stringer samples significantly increased Lifetimes to the unreinforced stringers.

The Tear stopper made of titanium or a titanium alloy are conventionally with the aircraft structure of aluminum or an aluminum alloy riveted. The disadvantage here is the high cost of the Attaching the rivets. Overall, this means a high production cost for an aircraft structure with crack stoppers.

task It is therefore the object of the present invention to provide a process for the preparation a suitable as a crack stopper component for an aircraft structure to be stated that with relatively little technical Expenditure is attachable. It is another task of the present Invention, a suitable as a crack stopper component for a Specify aircraft structure.

These Task is solved according to the invention the subject of the independent claims. Advantageous embodiments are the subject of the dependent claims.

One inventive method for producing a Component for an aircraft structure with at least one first cover layer, which is a first skin surface of the component formed, wherein the cover layer is substantially aluminum or a Aluminum alloy, and having a base body, comprising titanium or a titanium alloy, has the following steps on: It will be a first piece of titanium or a Titanium alloy provided. Further, a second workpiece made of aluminum or an aluminum alloy. The first Workpiece goes through with the second workpiece Plating connected.

Under a titanium material is here and in the following titanium or a Titanium alloy understood in the titanium a substantial and / or has the material properties significantly determining proportion. Under An aluminum material is analogous to aluminum or an aluminum alloy understood, in the aluminum, a material and / or the material properties has a significantly determinative share.

a The basic idea of the invention according to the riveting of the component can be replaced with the aircraft structure by gluing. Bonding titanium, however, is relatively complicated and not a standard process in aircraft construction. It requires a relatively extensive preparation the surfaces to be bonded. Furthermore At present there are too few experiences with aging such splices with titanium before, a spontaneous failure after aging is known, however. A use of such adhesive methods for Titanium in aircraft is therefore not possible.

on the other hand But should not be dispensed with the use of titanium materials because of their high strength as crack stopper and Doppler are particularly suitable.

Therefore is the the actual crack stopper forming titanium material with at least one cover layer made of aluminum or an aluminum alloy, so he is laying on the top layer with the aircraft structure underneath Use of standard bonding methods for Aluminum materials can be glued.

For the connection of the cover layers with the main body is a Plating methods such as roll cladding or accumulative roll bonding used. As it turns out, plating is very suitable good for connecting the cover layers with the base body.

The inventive method has the advantage that it provides a surface on the component, the can be permanently bonded by standard processes. A elaborate pretreatment of the surfaces to be bonded is no longer necessary. On the other hand, the use allows of the titanium basic body a high strength and resilience of the component.

There can be dispensed with the use of rivets, results In addition, a particularly advantageous in aircraft Weight savings.

In one embodiment of the method, a third workpiece made of aluminum or an aluminum alloy is further provided to form a second cover layer having a second skin surface surface of the component. The first workpiece is then placed between the second and third workpiece and connected to the second workpiece and the third workpiece by plating.

One Such component can be glued on two sides. It is also conceivable, other areas of the body with more Cover layers of aluminum materials to provide. However, to connect Plating methods are used, it is particularly advantageous only on one or two opposite sides of the Base body cover layers to install. The interfaces between the workpieces are then substantially parallel to each other Layers and the workpieces can be particularly good be joined together by plating.

For plating, it is possible to use a conventional roll-plating method or also an accumulative roll-bonding process (ARB), such as for example Saito et al: "Novel ultra-high straining process for bulk materials-development of the accumulative roll bonding (ARB) process", Acta mater. Vol. 47, No. 2, pages 579 to 583, 1999 is known.

At the ARB two ribbons are placed on each other and by rolling connected with each other. Subsequently, the resulting Band split in half, one above the other placed and in turn connected to each other by rollers. This The procedure is repeated as often as desired. This is how it forms a body of numerous individual layers and with high strength.

The ARB has with regard to the inventive method the advantage that relatively common and inexpensive materials such as titanium grade 2 can be used which by processing an extremely high strength receive.

In In one embodiment, prior to the ARB process, the surfaces become The individual layers of oxides are purified to make a good connection achieve.

The ARB process is performed, for example, at a temperature T _{1 of} 50 ° C ≤ T ₁ ≤ 250 ° C. At these temperatures, the titanium material is sufficiently ductile to be well processed, but recrystallization does not occur.

The plating for bonding the cover layers to the base body is carried out, for example, at a temperature T _{2 of} 15 ° C ≤ T ₂ ≤ 150 ° C. The temperature is chosen low enough so that the aluminum material of the cover layers does not soften so much that it is driven uncontrollably in front of the rollers.

Before the workpieces are joined together by plating, Advantageously, their surfaces are cleaned of oxides. This is done, for example, by pickling and / or brushing. A Such cleaning is advantageously carried out in the individual layers to be rolled together in the ARB process.

at a method for connecting the component to an aircraft structure, which has aluminum or an aluminum alloy takes place as already first described the manufacture of a component. Subsequently becomes the component with its first skin surface and, where appropriate also with a second skin surface (Doppler or stringer) glued to the aircraft structure.

In an embodiment, the first skin surface and / or the second skin surface and / or with the first Skin surface and the second skin surface To be bonded surfaces of the aircraft structure before the Bonding surface treated. This pretreatment of Surfaces is for bonding aluminum materials known and proportionate easy to perform.

One Component according to the invention for an aircraft structure has at least a first cover layer, which has a first skin surface of the component is formed. The cover layer essentially comprises aluminum or an aluminum alloy. Furthermore, the component comprises a Basic body comprising titanium or a titanium alloy, wherein the first cover layer with the main body by plating connected is.

In In one embodiment, the component further comprises a second one Cover layer on which a second skin surface of the component formed. The second cover layer also essentially comprises aluminum or an aluminum alloy.

typically, are the first and the second skin surface of the component formed largely parallel to each other and, for example, largely planar. In one embodiment, the base body a plurality of layers substantially parallel to the first skin surface and optionally the second Skin surface are aligned. Such layers can in an ARB process as described above. Then The layers are connected by plating and exist all essentially of the same material.

The component according to the invention has the advantage that it is advantageous as a crack stopper or Doppler can be used in an aircraft structure. At the same time, it enables the use of titanium as a material for crack arrestors and the elimination of riveted connections, since the skin surfaces of the component made of an aluminum material can be bonded well and with standard processes.

in the Below is an embodiment of the invention based a drawing explained in more detail. It shows

1 schematically a cross section through a component according to an embodiment of the invention and

2 schematically a cross section through a component according to a second embodiment of the invention.

Same Parts are identified in both figures with the same reference numerals.

The component 1 according to 1 has a basic body 2 made of a titanium material. On one side is the main body 2 with a first cover layer 3 and on a second side with a second topsheet 4 provided, wherein the first cover layer 3 and the second cover layer 4 have an aluminum material. The first cover layer 3 forms a first skin surface 5 of the component 1 off and the second top layer 4 a second skin surface 6 , The first skin surface 5 , the second skin surface 6 and the first interface 7 and the second interface 8th between the main body 2 and the top layers 3 . 4 are essentially parallel to each other.

The cover layers 3 . 4 were joined to the base by plating. This indicates the component 1 a base body which is made of a titanium material and therefore has a high strength, and is still on the cover layers 3 . 4 made of an aluminum material with aluminum structures bondable.

The thickness of the cover layers 3 . 4 is chosen so that a surface treatment, as is usual before the bonding of aluminum materials, the cover layers 3 . 4 not damaged.

2 schematically shows a second embodiment of the component 1 in which the main body 2 from a number of layers 9 consists. The individual layers 9 were connected to a basic body in an ARB process. For this purpose, individual strips or plates were provided whose surfaces 10 freed of oxides and the plates joined together by plating. At the same time, a very fine submillimeter structure arises in the rolled layers. Subsequently, the resulting plate was divided into two parts and these were again joined together by plating. This often repeated process has become the basic body 2 according to 2 guided.

For the layers 9 For example, a moderately strong titanium material such as titanium grade 2 which, thanks to the ARB process, has a high strength comparable to that of materials such as Ti-Al6-V4.

1

component

2

body

3

first topsheet

4

second topsheet

5

first skin surface

6

second skin surface

7

first interface

8th

second interface

9

layer

10

surface

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited non-patent literature

• - Saito et al: "Novel ultra-high straining process for bulk materials-development of the accumulative roll bonding (ARB) process", Acta mater. Vol. 47, No. 2, pages 579 to 583, 1999 [0016]

Claims (17)

Method for producing a component ( 1 ) for an aircraft structure having at least a first cover layer ( 3 ), which has a first skin surface ( 5 ) of the component ( 1 ), wherein the first cover layer ( 3 ) substantially comprises aluminum or an aluminum alloy, and a base body ( 2 ) comprising titanium or a titanium alloy, the method comprising the steps of: providing a first workpiece of titanium or a titanium alloy; - Providing a second workpiece made of aluminum or an aluminum alloy, and - Connecting the first workpiece with the second workpiece by plating. The method of claim 1, further comprising providing a third aluminum or aluminum alloy workpiece to form a second liner (U.S. 4 ), which has a second skin surface ( 6 ) of the component ( 1 ), the first workpiece between the second and the third workpiece is arranged and connected to the second workpiece and the third workpiece by plating. Method according to claim 1 or 2, wherein the second workpiece comprises a plurality of layers ( 9 ), which are interconnected by an accumulative roll bonding process. Method according to claim 3, wherein prior to roll bonding the surfaces ( 10 ) of the individual layers ( 9 ) are cleaned of oxides. The method of claim 3 or 4, wherein the accumulative roll bonding process is performed at a temperature T _{1 of} 50 ° C ≤ T ₁ ≤ 250 ° C. Method according to one of claims 1 to 5, wherein the plating at a temperature T ₂ with 15 ° C ≤ T ₂ ≤ 150 ° C is performed. Method according to one of claims 1 to 6, wherein prior to plating surfaces of the workpieces be purified by oxides. Method for connecting the component ( 1 ) having an aircraft structure comprising aluminum or an aluminum alloy, the method comprising the steps of: - producing a component ( 1 ) according to any one of claims 1 to 7; - bonding the component ( 1 ) with its first skin surface ( 5 ) with the aircraft structure. The method of claim 8, wherein also a second skin surface ( 6 ) of the component ( 1 ) is glued to the aircraft structure. A method according to claim 8 or 9, wherein the first skin surface ( 5 ) and / or the second skin surface ( 6 ) and / or with the first skin surface ( 5 ) and the second skin surface ( 6 ) to be bonded surfaces of the aircraft structure are surface treated prior to bonding. Component ( 1 ) for an aircraft structure, comprising - at least a first cover layer ( 3 ), which has a first skin surface ( 5 ) of the component ( 1 ), wherein the first cover layer ( 3 ) substantially comprises aluminum or an aluminum alloy, and - a base body ( 2 ) comprising titanium or a titanium alloy, wherein the first cover layer ( 3 ) with the basic body ( 2 ) is connected by plating. Component ( 1 ) according to claim 11, which has a second cover layer ( 4 ), which has a second skin surface ( 6 ) of the component ( 1 ), wherein the second cover layer ( 3 ) also essentially comprises aluminum or an aluminum alloy. Component according to claim 11 or 12, wherein the basic body ( 2 ) a plurality of layers ( 9 ) substantially parallel to the first skin surface ( 5 ) and optionally the second skin surface ( 6 ) are aligned. Component according to claim 13, wherein the layers ( 9 ) are joined together by plating. Component according to claim 13 or 14, wherein all layers ( 9 ) consist essentially of the same material. Aircraft structure, the aluminum or an aluminum alloy and at least one component ( 1 ) according to one of claims 11 to 15. Use of the component ( 1 ) according to one of claims 11 to 15 as a crack stopper in an aircraft structure.