Abstract
A multilayer composite material may include at least one nonmetallic layer, which in some examples comprises plastic, and at least one metallic layer comprising a first metallic shape memory material. One problem with specifying multilayer composite materials and methods for producing multilayer composite materials relative to reshaping properties can be overcome by providing at least one second metallic layer and disposing the at least two metallic layers on opposite sides of the nonmetallic layer. Further disclosed are methods for producing multilayer composite materials, as well as semi-finished products produced from such multilayer composite materials. Still further disclosed are methods for producing components using such semi-finished products.
Claims
1.-20. (canceled)
21. A multilayer composite material comprising: a nonmetallic layer; a first metallic layer comprising a metallic shape memory material; and a second metallic layer, wherein the first and second metallic layers are disposed on opposite sides of the nonmetallic layer.
22. The multilayer composite material of claim 21 wherein the metallic shape memory material has a shape memory of a shape introduced previously to the metallic shape memory material.
23. The multilayer composite material of claim 21 wherein the nonmetallic layer comprises a thermoplastic.
24. The multilayer composite material of claim 23 wherein a glass transition temperature or a melting temperature of the thermoplastic is in a range of ±100° C. of an activation temperature of the metallic shape memory material.
25. The multilayer composite material of claim 21 wherein the nonmetallic layer comprises fiber-reinforced plastic.
26. The multilayer composite material of claim 21 wherein the metallic shape memory material comprises an iron-based shape memory alloy.
27. The multilayer composite material of claim 21 wherein a thickness of the first metallic layer is between 0.15 and 1.0 mm.
28. The multilayer composite material of claim 21 wherein a thickness of the nonmetallic layer is between 0.3 and 2.0 mm.
29. The multilayer composite material of claim 21 wherein the second metallic layer comprises a metallic shape memory material.
30. The multilayer composite material of claim 21 wherein one of the first and second metallic layers comprises aluminum or an aluminum alloy.
31. The multilayer composite material of claim 21 configured in a coil form.
32. A method for producing a multilayer composite material that comprises a nonmetallic layer comprising plastic, a first metallic layer comprising a metallic shape memory material, and a second metallic layer, with the first and second metallic layers being disposed on opposite sides of the nonmetallic layer, the method comprising: joining the first metallic layer to the nonmetallic layer; and joining the nonmetallic layer to the second metallic layer.
33. The method of claim 32 further comprising: heating the first metallic layer at least to an activation temperature; preshaping the first metallic layer; and cooling the first metallic layer to a temperature below the activation temperature after the first metallic layer is heated and preshaped; and reshaping the first metallic layer.
34. The method of claim 33 wherein the reshaping of the first metallic layer is performed concurrently with the joining of the first metallic layer to the nonmetallic layer.
35. The method of claim 32 wherein the second metallic layer comprises a shape memory material.
36. The method of claim 32 further comprising joining the nonmetallic layer to third metallic layer, the third metallic layer comprising aluminum or an aluminum alloy.
37. The method of claim 32 wherein the multilayer composite material is produced in a coil-to-coil process.
38. The method of claim 32 wherein the multilayer composite material is produced in a coil-to-sheet process.
39. A semi-finished product produced from a multilayer composite material that comprises a nonmetallic layer, a first metallic layer comprising a metallic shape memory material, and a second metallic layer, with the first and second metallic layers being disposed on opposite sides of the nonmetallic layer.
40. A method for producing a component using the semi-finished product of claim 39, wherein the semi-finished product is heated at least to an activation temperature of the metallic shape memory material, wherein the semi-finished product reshapes itself via a shape memory of the metallic shape memory material.
Description
[0070] Regarding the refinements and advantages of the method for producing a multilayer composite material, of the semi-finished product produced from a multilayer composite material of the invention, and of the method for producing a component using a semi-finished product of the invention, reference is further made to the details given concerning the multilayer composite material of the invention, and also to the drawing. In the drawing
[0071] FIG. 1a) shows in a sectional view, a first exemplary embodiment of a multilayer composite material,
[0072] FIG. 1b) shows, in a sectional view, a second exemplary embodiment of a multilayer composite material,
[0073] FIG. 1c) shows in a sectional view a third exemplary embodiment of a multilayer composite material,
[0074] FIG. 2a)-e) show, in a sectional view, an exemplary embodiment of a method for producing a multilayer composite material,
[0075] FIG. 2f)-g) show, in a sectional view, two components produced from the multilayer composite material of the invention,
[0076] FIG. 3a) shows a first exemplary embodiment of a schematic construction of a method for producing a multilayer composite material in a coil-to-coil process,
[0077] FIG. 3b) shows a second exemplary embodiment of a schematic construction of a method for producing a multilayer composite material in a coil-to-coil process,
[0078] FIG. 4a) shows a third exemplary embodiment of a schematic construction of a method for producing a multilayer composite material in a coil-to-sheet process,
[0079] FIG. 4b) shows a fourth exemplary embodiment of a schematic construction of a method for producing a multilayer composite material in a coil-to-sheet process,
[0080] FIG. 5a) shows an exemplary embodiment of a semi-finished product composed of a multilayer composite material of the invention, in a perspective representation,
[0081] FIG. 5b) shows a component produced from the semi-finished product from FIG. 5a), in a perspective representation.
[0082] FIG. 1a) shows, in a sectional view, a first exemplary embodiment of a multilayer composite material 2, wherein a nonmetallic core layer 4, preferably comprising plastics, is joined to a metallic layer, preferably a facing sheet 6, which comprises a metallic shape memory material. The facing sheet 6 preferably comprises an iron-based shape memory alloy, and the core layer 4 preferably comprises a fiber-reinforced thermoplastic, as for example a carbon fiber-reinforced blend of polyamide and polyethylene. In particular, the shape memory material of the facing sheet 6 has a shape memory of a shape which is different from the shape shown here of the shape memory material in the multilayer composite material.
[0083] FIG. 1b) shows, in a sectional view, a second exemplary embodiment of a multilayer composite material 2′, wherein, in comparison to the exemplary embodiment shown in FIG. 1a), a further metallic facing sheet 8 is joined to the core layer 4 on the side opposite the facing sheet 6. The further facing sheet 8 here may comprise different materials, as for example aluminum or an aluminum alloy. The facing sheet 8, however, may also comprise a metallic shape memory material, like the facing sheet 6. In this case, in particular, the shape memory material of the facing sheet 8 may have a shape memory which corresponds to the shape memory of the first facing sheet 6, and so the reshaping properties of the facing sheets 6, 8 support one another on activation. In particular the facing sheets 6, 8 also approximately have the same thickness, and so the multilayer composite material is approximately symmetrical along its thickness. Alternatively it is also possible to use a metallic facing sheet 8 without shape memory quality.
[0084] Alternatively, as shown in FIG. 1c), the multilayer composite material 2″ may have two or more nonmetallic layers as core layers 4a, 4b, in which case a metallic layer 6 with shape memory is disposed between the layers 4a, 4b. A multiplicity of further combinations and dispositions of the layers are conceivable.
[0085] FIG. 2a)-e) show, in a sectional view, an exemplary embodiment of a method for producing a multilayer composite material 2, 2′. First of all, in FIG. 2a) a metallic layer is provided, a metallic facing sheet 6 which comprises a shape memory material, for example. This facing sheet 6 may be in coil form. The facing sheet is heated at least to the activation temperature of the shape memory material and is preshaped, into a circular or oval shape, for example, as shown in FIG. 2b). Optionally thereafter the facing sheet in FIG. 2c) is cooled to a temperature below the activation temperature and reshaped, back into a coil form, for example. The activation may alternatively be brought about, for example, via a corresponding magnetic field. Lastly, the facing sheet 6 is joined to a nonmetallic layer, such as to the core layer 4, for example, in which case the reshaping of the facing sheet 6 may take place before the joining to the core layer 4, as shown in FIG. 2c), or simultaneously with the joining to the core layer 4 in FIG. 2d). The multilayer composite material 2 in FIG. 2d) then corresponds to the exemplary embodiment shown in FIG. 1a), with the shape memory material having a shape memory via the shape shown in FIG. 2b) or, alternatively, a shape between FIG. 2b) and FIG. 2a), if the shape memory effect is designed such that no complete return to shape takes place.
[0086] As shown in FIG. 2e), a metallic layer, as for example a further facing sheet 8, may be joined to the core layer 4, in which case the facing sheet 8, subsequently to or else simultaneously with the joining of the first facing sheet 6 to the core layer 4, may be disposed in the multilayer composite material 2′. The multilayer composite material 2′ in FIG. 2e) then also corresponds to the exemplary embodiment shown in FIG. 1b), with the shape memory material having a shape memory via the shape shown in FIG. 2b) or having a shape between FIG. 2b) and FIG. 2a).
[0087] FIG. 2f) shows, in a sectional view, a component 10 produced from the multilayer composite material 2 shown in FIG. 2d). The component 10 may be produced by means of forming tools, in which case, additionally, the reshaping qualities of the shape memory material may be utilized by heating at least to the activation temperature. In particular, however, the production of the component 10 is accomplished only by the heating of the multilayer composite material 2 at least to the activation temperature at which the shape memory of the shape memory material in the facing sheet 6 is activated, and the shape of the facing sheet 6 from FIG. 2b), or a shape between FIG. 2b) and FIG. 2a), is re-established. In that case the multilayer composite material 2 is a self-reshaping material.
[0088] In analogy to this, FIG. 2g) shows a component 10′ produced from the multilayer composite material 2′ shown in FIG. 2e).
[0089] FIG. 3a) shows a first exemplary embodiment of a schematic construction of a method for producing a multilayer composite material 2 in a coil-to-coil process, wherein first of all a metallic facing sheet 6 in coil form is unwound from a coil 12. In a first preshaping stage 14, the facing sheet 6 is heated at least to the activation temperature T.sub.A and preshaped. Subsequently, in the second, reshaping stage 16, the facing sheet 6 is cooled below the activation temperature T.sub.A and reshaped, to regain the coil form, for example. The material of the core layer 4 is unwound from a second coil 18 and joined to the facing sheet 6 to form a multilayer composite material 2, in a joining apparatus 20—for example, as shown here, by means of a coil press. Shown in simplified form in FIGS. 3 and 4 is only one coil 18 for the provision of the material of the core layer 4; however, for fiber-reinforced plastics within the core layer, in particular, it is possible to use a plurality of coils—for example, separate coils for a fiber fabric and a plastics matrix. Lastly, the multilayer composite material 2 produced is wound onto a further coil 22.
[0090] FIG. 3b) shows a second exemplary embodiment of a schematic construction of a method for producing a multilayer composite material 2 in a coil-to-coil process. The method shown in FIG. 3b) differs from the method shown in FIG. 3a) in that in FIG. 3b), instead of a separate second reshaping stage 16 and a joining apparatus 20, the reshaping of the facing sheet 6 below the activation temperature T.sub.A, and the joining to the core layer 4, is brought about in a single joining apparatus 24. In this way it is possible to economize by one method step.
[0091] FIG. 4a) shows a third exemplary embodiment of a schematic construction of a method for producing a multilayer composite material 2 in a coil-to-sheet process. The method shown in FIG. 4a) differs from the method shown in FIG. 3a) in that in FIG. 4a) the multilayer composite material 2 is not wound onto a coil 22, but is instead processed to sheets 28 in a coil divider 26 downstream of the joining apparatus 20.
[0092] FIG. 4b) shows a fourth exemplary embodiment of a schematic construction of a method for producing a multilayer composite material in a coil-to-sheet process, in which, in analogy to FIG. 3b), the reshaping of the facing sheet 6 below the activation temperature T.sub.A and the joining to the core layer 4 is brought about in a single joining apparatus 24.
[0093] FIG. 5a) shows an exemplary embodiment of a semi-finished product 30 composed of a multilayer composite material of the invention, in a perspective representation. In this exemplary embodiment, the semi-finished product is produced from a multilayer composite material 2 with a core layer 4 and a facing sheet 6. The multilayer composite material 2 here has already been cut into a shape corresponding to the component 10 to be produced, and has goal-directed technical properties which take account of the shape memory effect.
[0094] For producing the component 32 in FIG. 5b), the semi-finished product 30 may first be heated at least to the activation temperature of the shape memory material and subsequently, in particular with incorporation of a shape memory, may be reshaped into the ultimate shape of the component 32. The facing sheet 6 of the semi-finished product 30 preferably has a shape memory via a shape which corresponds to the component 32 to be produced. In that case the component 32 can be produced only by heating of the semi-finished product 30 above the activation temperature T.sub.A, through activation of the shape memory material, without further forming tools.
