METHOD FOR PRODUCING A COMPOSITE MATERIAL

Abstract

Disclosed is a method for producing a composite material, wherein two or more composite components are arranged with respect to one another by casting to form a composite, so as to create a contact region essentially without a material bond between the composite components, wherein the composite components are thereafter materially bonded to one another in the contact region by means of a hot-rolling process.

Claims

1.-15. (canceled)

16. A method for producing a composite material, the method comprising: providing a solid first composite component; casting a second composite component in contact with the first composite component to create a third composite component, wherein for the third composite component, a contact region is formed between the first composite component and the second composite component in which there is no material bond between the first composite component and the second composite component in the contact region; and materially bonding the first composite component to the second composite component in the contact region by hot-rolling the third composite component.

17. The method of claim 16, wherein said casting step comprises one of casting the second composite component around the first composite component or casting the second composite component into a construction space bounded by the first component.

18. The method of claim 17, wherein the first composite component includes one or more of a core, a rod, and a plate, and wherein the second composite component made from a melt.

19. The method of claim 16, wherein said casting step comprises creating a temperature difference of at least 500° C. between the first composite component and the second composite component.

20. The method of claim 16, wherein the created third composite component has a volumetric proportion of an inner composite component of at least 30% of the total volume.

21. The method of claim 16, wherein the casting step is performed in a permanent mold.

22. The method of claim 16, wherein said materially bonding step comprises deforming the created third composite component in order to compress voids.

23. The method of claim 16, wherein during said casting step, the third composite component that is created has a form-fitting engagement between the first composite component and the second composite component.

24. The method of claim 16, wherein at least one of the first component or the second component is made from one or more of a carbon steel, a rust-, acid- and heat-resistant steel, an FeAlCr steel, a Ni—, Ti—, Al— or Mg alloy and an FeMn steel.

25. The method of claim 16, wherein said first composite component is formed as one of a casting mold or shell.

26. The method of claim 16, further comprising, prior to said materially bonding step, heating the third composite component to a hot-rolling temperature.

27. A device for producing a composite material by the casting of a first composite component in contact with a second composite component to create a third composite component having a contact region without a material bond between the first and second composite components, and then materially bonding the first and second composite components in the contact region by hot-rolling the third composite component, the device comprising: a permanent mold configured to permit the second composite component to be cast in contact with the first composite component to create the third composite component; and a rolling device configured to hot-roll the third composite component and materially bond the first and second composite components in the contact region.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0028] FIG. 1 shows, schematically, a method according to a first exemplary embodiment of the present invention.

[0029] FIGS. 2a to 2e show, schematically, various casting molds for a method according to a second exemplary embodiment of the present invention.

[0030] FIGS. 3a to 3e show, schematically, various casting molds for a method according to a third exemplary embodiment of the present invention.

EMBODIMENTS OF THE INVENTION

[0031] In the various figures, identical parts are always provided with the same reference signs and are therefore in general also named or mentioned only once each.

[0032] FIG. 1 shows, schematically, a method for producing a composite material according to a first exemplary embodiment of the present invention. In particular, the method is intended for the creation of a composite material consisting of at least two composite components, wherein two different materials are used as the composite components. The use of different composite components is aimed at creating a composite material which, as much as possible, brings together the respective properties of the individual, different composite components in the composite material. Therefor, a slab-shaped or block-shaped composite 4 made of the desired composite components is preferably provided prior to cladding in a rolling process, preferably with a desired layer thickness distribution. Then, the composite 4 is preferably rolled using rollers 3 to form the composite material in the form of a hot strip. The prior art contains methods in which the composite components are stacked one atop the other to form the composite 4, and are then peripherally welded. In order to create a full-area material bond between the composite components in the composite 4, it is necessary in this context that the surfaces of the composite components be clean and scale-free at the point of the first broaching in a rolling device 6 or roll stand provided for the rolling. The peripheral welding is intended to satisfy these requirements. If the composite components are components which, for example with regard to their temperature behavior and in particular with regard to their thermal expansion behavior, are fundamentally different upon reheating to a hot-rolling temperature, it is impossible to reliably prevent subsequent scale formation between the composite components as a consequence of failure of the weld seam. There is therefore a need to provide a method with which it is possible to provide a composite 4 which can easily be rolled into a composite material.

[0033] For producing the composite material, it is provided that, in a second method step, the composite components are arranged with respect to one another by means of a casting process, preferably in a permanent mold 11, so as to essentially avoid the formation of a material bond in a contact region. In particular, the casting process avoids the peripheral welding of the composite components. In that context, it is preferably provided that a second composite component 2 is cast around a first composite component 1 in the permanent mold 11. Contraction of the second composite component 2, which takes place in the context of the casting process, results in the second composite component 2 then being preferably mechanically joined with the first composite component 1 in a form-fitting manner such that the first composite component 1 is enclosed by the second composite component 2, and air inclusions between the first and second composite components 1 and 2 are minimized. Also, the casting process results in an essentially mechanical composite 4 which comprises the composite components and withstands transport, heating to the rolling temperature in the reheating furnace and broaching in a roughing train of the hot-rolling device 6 or of the hot-rolling mill without undesired separation of the composite components, or one composite component separating from the other. In a third method step subsequent to the second method step, the material bond to form the composite material is then created by the hot-rolling process.

[0034] When forming the composite 4, it is in particular provided that, during the casting process, melting of the second composite component 2 onto the first composite component 1 is at least partially avoided. Such a material bond-free connection is preferably brought about by superheating just one of the two connection components. It is in particular provided that, in the second method step, there is a temperature difference of greater than 500° C. between the respective composite components. It is also provided that any voids between the composite components are compacted in the context of deformation following the casting process. It is also provided that the first composite component 1 and/or the second composite component 2 are deformed in the second method step such that they engage in a form-fitting manner. For example, use is made, as the first composite component 1, of slab sections having oscillation marks which engage in a form-fitting manner with the solidified second composite component 2 such that this form fit promotes adhesion between the composite components, in particular during transport of the composite 4. It is also provided that, for example, the volume fraction of a first composite component 1 arranged inside the composite 4 makes up at least 30% of the total volume of the composite. Use is preferably made of combinations of carbon steels, rust-, acid- and heat-resistant steels, FeMn steels, FeAlCr steels, Ni—, Ti—, Al— or Mg alloys. Examples of possible combinations are shown in the following table:

TABLE-US-00001 Second or first composite First or second composite component component carbon steel rust-, acid- and heat-resistant steel carbon steel Ni alloy rust-, acid- and heat-resistant steel Ni alloy rust-, acid- and heat-resistant steel FeAlCr steel rust-, acid- and heat-resistant steel Ti alloy rust-, acid- and heat-resistant steel Al alloy carbon steel FeMn steel carbon steel FeAlCr steel rust-, acid- and heat-resistant steel Mg alloy FeAlCr steel Ni alloy

[0035] FIGS. 2a-2e show, schematically, casting molds for a method for producing a composite material according to a second exemplary embodiment of the present invention. In that context, the permanent mold 11 and the first composite component preferably essentially form the casting mold for the second composite component. It is in particular provided that the first composite component 1 forms a core around which is cast, in the casting process of the second method step, a melt 21 forming the second composite component 2, as shown in FIG. 2a. In the casting process, the melt 21 preferably takes up the space provided as construction space or interspace between the permanent mold 11, in particular by the boundary of the permanent mold 13, and the core 1. It is in particular conceivable for the first composite component 1 to have many parts, as illustrated in FIGS. 2b to 2e. For example, multiple first composite components 1 are oriented such that they run essentially parallel to an edge or boundary of the permanent mold 13, wherein the edge of the permanent mold defines the construction space available for the casting process. It is also conceivable for multiple first composite components 1 to be arranged with respect to one another in the manner of a chessboard (see FIGS. 2d and 2e). It is further conceivable for the first composite component to have any structure 24 in cross section. For example, the structure is at least partially angular (2a to 2d) or circular or elliptical (see FIG. 2e).

[0036] FIGS. 3a-3e show, schematically, casting molds for a method for producing a composite material according to a second exemplary embodiment of the present invention. For this embodiment, it is provided that the casting mold is formed by the second composite component 2 which, in the casting process, is filled with the first composite component 1. It is in particular provided that the second composite component 2 forms a shell 22 which is for example made of plates 23. The method is then preferably used to produce a multi-layer, preferably three-layer composite material, with the central part of the composite material consisting of the first composite component 1 which is in turn encapsulated by the second composite component 2. It is further conceivable for the second composite component 2, which is essentially formed as a casting mold, to have recesses into which the first composite component 1 is poured in the casting process. In particular, the recesses are arranged such that they run at least partially parallel and/or perpendicular to the edge of the second composite component 2. In that context, it is also conceivable that the recesses spread in the manner of a chessboard along a cross section through the second composite component 2. In particular, a structure bounding the recess may be in any desired configuration. For example, the structure 24 of one or more recesses is rectangular, circular or elliptical. It is further conceivable for recesses of different structures 24 and/or different sizes to be arranged in regular and/or irregular fashion along the cross section.

LIST OF REFERENCE SIGNS

[0037] 1 first composite component [0038] 2 second composite component [0039] 3 roller [0040] 4 composite [0041] 5 roller axis [0042] 6 hot-rolling device [0043] 11 permanent mold [0044] 13 boundary of the permanent mold [0045] 21 melt [0046] 22 shell [0047] 23 plate [0048] 24 contour profile