Method for producing a hybrid component

Abstract

Method for producing a hybrid component (10) made of at least two different materials, the method comprising the following steps: - providing a substrate (11, 20) made of a substrate material, to which at least one functional element (12) is to be applied in a functional region of the substrate (11, 20), - creating a first functional layer (21) made of a thermosetting resin system (21) on the substrate (11, 20) at least within the functional area of the substrate (11, 20), - applying at least one second functional layer (22) made of a thermoplastic material (22) to the first functional layer (21), - wherein the thermosetting resin system (21) and the thermoplastic material (22) are selected such that both form a material bond after consolidation, and - applying a thermoplastic material different from the substrate material to this second functional layer (22) thus produced on the substrate (11, 20) in order to produce the functional element (12) on the substrate (11, 20), wherein the substrate material is a metal material or contains such a material, wherein before the first functional layer (21) is applied to the metal substrate, the oxide layer of the metal substrate is first removed at least in the functional area and after the oxide layer has been removed and before the first functional layer (21) is applied to the metal substrate, a primer (21a) is applied.

Description

[0001] The invention relates to a method for producing a hybrid component which is made from at least two different materials.

[0002] Additive manufacturing, also known as 3D printing, is an emerging manufacturing technology increasingly used to produce components for applications in the transportation sector, particularly aerospace. Compared to conventional manufacturing processes, additive manufacturing technologies offer tremendous potential for mass production, cost reduction, and supply chain simplification, as they provide the ability to produce parts on-site on demand without the need for costly warehousing facilities.

[0003] A disadvantage of additive manufacturing is the significantly slower production rates compared to conventional manufacturing techniques, which complicates economically viable applications of additively manufactured parts. Furthermore, additive manufacturing processes can generally only produce components that are integrally made from a single material. Hybrid components made from two or more different materials are difficult to produce using additive manufacturing processes.

[0004] Such hybrid components often consist of a base substrate to which at least one functional element is attached. These functional elements comprise a material, or are made of a material, that differs from the material of the base substrate. This allows components to be manufactured in which the material selection is adapted to the respective function of the functional element and which are thus optimized either in terms of stability / rigidity and / or weight, or which exhibit additional functions such as electrical conductivity, defined thermal conductivity, or even sensory properties.

[0005] US 2016 / 0325380 A1 discloses a method for manufacturing a component composed of multiple materials. A first subcomponent made of a first material is provided, to which a second subcomponent made of a second material is applied. The disadvantage of this method is that only chemically compatible materials can be used to ensure a resilient connection between the subcomponents. Furthermore, in applications where the final component is exposed to temperature fluctuations, the different thermal expansion coefficients of the materials lead to different expansions and contractions, resulting in stresses that may potentially cause the connection to fail.

[0006] DE 10 2013 114 829 A1 discloses a method for producing a hybrid component in which a thermoplastic component is to be bonded to a thermoset component. For this purpose, a multi-layered functional layer comprising at least one thermoplastic material is applied to the thermoset component in order to attach the thermoplastic component to this functional layer.

[0007] DE 10 2018 121 336 A1 relates to a method for producing a fiber composite component, wherein a film-like adhesion promoter is first provided, to which a functional element is attached on a first side surface. Subsequently, the film-like adhesion promoter is applied to a fiber preform with the second side surface.

[0008] JP S63 - 295 692 A describes a process for coating metallic components to provide corrosion protection. First, the oxide layer is removed by sandblasting and chromated. Then, an epoxy resin primer is applied, followed by a two-layer PE film.

[0009] Against this background, it is the object of the present invention to provide an improved method with which hybrid components made of different materials can be produced with a resilient connection.

[0010] The object is achieved according to the invention with the method for producing a hybrid component according to claim 1. Advantageous embodiments of the invention can then be found in the corresponding subclaims.

[0011] According to claim 1, a method is proposed for producing a hybrid component made from at least two different materials. One of the materials is a thermoplastic material, while the other material is a different material, for example a metal or a thermosetting material. The other material is at least not a thermoplastic material, so that the hybrid component is made from a thermoplastic material and a material that is not a thermoplastic material. These thermosetting and / or thermoplastic materials can be provided with fillers, for example with short or continuous fibers made of, for example, glass, carbon fiber, aramid, basalt or other materials (including nanoparticles).

[0012] The method according to the invention comprises the following steps: - Providing a substrate made of a (non-thermoplastic) substrate material, to which at least one functional element is to be applied in a functional area of the substrate, - Creating a first functional layer of a thermosetting resin system on the substrate at least within the functional area of the substrate, - applying at least one second functional layer made of a thermoplastic material to the first functional layer, - the thermosetting resin system and the thermoplastic material are selected so that both form a material bond after consolidation, and - Applying a thermoplastic material different from the substrate material to the substrate in the region of the second functional layer in order to produce the functional element on the substrate.

[0013] Accordingly, a substrate made of a substrate material is first provided, onto which at least one functional element is to be applied in a functional region of the substrate. The functional element is to be made of a thermoplastic material, while the substrate is made of another substrate material that is not a thermoplastic material. In a particularly preferred embodiment, the functional element is produced in an additive manufacturing process directly on the second functional layer by applying the thermoplastic material, for example, in the form of a 3D print.

[0014] To ensure the application of the functional element made of thermoplastic material with a process-safe and reliable bond, a first functional layer made of a thermosetting resin system is first applied to the substrate within the functional area. It is advantageous if the thermosetting resin system is compatible with the substrate material, such that the thermosetting resin system and the substrate material form a material bond. This means that, in the best case scenario, the thermosetting resin system forms a chemical bond with the substrate material, creating a firm and secure bond between the substrate and the first functional layer.

[0015] In a second step, a second functional layer made of a thermoplastic material is applied to this first functional layer. The thermosetting resin system and the thermoplastic material are selected such that both form a material bond after curing. This means that the first functional layer and the second functional layer form a chemical bond, for example in the form of a diffusion bond and / or through covalent bonds between the thermosetting resin system and the thermoplastic material, in order to create a functional bond between the first functional layer and the second functional layer.

[0016] The functional element, which is also made of a thermoplastic material or consists of such a material or has such a material, can now be applied to this second functional layer made of a thermoplastic material produced on the substrate and bonded to the second functional layer.

[0017] With the aid of the present invention, it is therefore possible to firmly and securely arrange a thermoplastic functional element on a provided substrate in order to produce a corresponding hybrid component. The first and second functional layers ensure that the thermoplastic functional element can be firmly and securely arranged on the substrate even if the substrate material is not made of a thermoplastic material.

[0018] A material bond between the first functional layer and the second functional layer is understood in particular to mean that the thermosetting resin system of the first functional layer and the thermoplastic material of the second functional layer form a chemical bond, for example via a diffusion bond and / or covalent bonds. Both the thermosetting resin system and the thermoplastic material are therefore selected so that such a material bond is possible between the two materials.

[0019] Materials such as PEI (polyetherimide), PES (polyethersulfone), PSU (polysulfone), or PA (polyamide) are suitable for the thermoplastic functional layer, as they demonstrate good chemical compatibility with the epoxy resin molecules. Many thermoplastic materials have been shown to be compatible with these systems, so the subsequently applied thermoplastic functional element does not necessarily have to be PEI, but can also be a material from the polyaryletherketone (PAEK, e.g., PEEK) group (polyetheretherketone) or thermoplastics from other material groups.

[0020] This makes it possible to attach functional elements made of a thermoplastic material to a substrate even when direct adhesion is not possible due to the substrate material being incompatible with the thermoplastic material. These bridges can be closed by applying the first and second functional layers and creating a corresponding functional composite.

[0021] For thermosetting materials, consolidation within the meaning of the present invention refers in particular to the hardening of the matrix. This means, in particular, that true chain bonds between the molecules are formed or newly formed (crosslinking). For thermoplastic materials, consolidation refers in particular to the hardening or solidification of the material, which melts upon application of heat and solidifies again upon cooling.

[0022] According to one embodiment, it is provided that the first and second functional layers are consolidated before the thermoplastic material is applied to produce the thermoplastic functional element.

[0023] By curing the first and second functional layers in a preferably joint curing process (co-curing), it can be ensured that the two materials form a material bond, for example in the form of a chemical bond, and thus establish a firm and stable connection.

[0024] According to one embodiment, it is provided that the thermosetting resin system is an epoxy resin system and / or that the thermoplastic material is a PEI, PSU, PES or PA.

[0025] According to one embodiment, the thermoplastic material is applied to the first functional layer in the form of a thermoplastic film.

[0026] According to the invention, it is further provided that the substrate material is or contains a metal material. Such metals can be, for example, aluminum, titanium, or stainless steel.

[0027] For this purpose, it is intended that before applying the first functional layer to the metal substrate, the oxide layer of the metal substrate is first removed, at least in the functional area.

[0028] This advantageously significantly improves the adhesion of the first functional layer in the form of a thermosetting resin system to the metal substrate, whereby the entire functional composite can be firmly and securely arranged on the substrate.

[0029] It is also planned that a primer will be applied to the metal substrate after the oxide layer has been removed and before the first functional layer is applied.

[0030] The use of a primer can improve the adhesion of the first functional layer to the substrate.

[0031] According to one embodiment, it is provided that the first functional layer is applied in such a way that the material thickness of the first functional layer is less than 1 mm.

[0032] According to one embodiment, it is provided that the second functional layer is applied in such a way that the material thickness is less than 10 mm.

[0033] According to one embodiment, it is provided that the functional element is produced on the second functional layer by printing or spraying the thermoplastic material.

[0034] The functional element is manufactured from the thermoplastic material directly on the substrate in a second manufacturing process (e.g. 3D printing, overmolding, hot pressing, etc.) to create the hybrid component.

[0035] However, it is also conceivable that the functional element is manufactured separately with regard to its basic guardian geometry and is connected to the second functional layer in a subsequent joining process.

[0036] With the present invention, a particularly good layer adhesion is achieved in comparison to other possibilities, such as gluing, in that an interdiffusion is created between the thermosetting epoxy resin layer and the thermoplastic functional layer between the first functional layer and the second functional layer, wherein a thermoplastic can be subsequently applied to the thermoplastic functional layer to produce or arrange the functional element.

[0037] The invention is explained in more detail by way of example with reference to the accompanying figures. They show: Fig. 1 perspective view of a hybrid component, Fig. 2 schematic representation of the production of the substrate with the functional composite.

[0038] Fig. 1 shows a perspective view of a hybrid component 10, which comprises a substrate 11 and a functional element 12 arranged on the substrate 11. In the example in Fig. 1, the functional element 12 is a stringer for stiffening the substrate 11, which is formed from a hybrid metal-polymer plate.

[0039] Fig. 2 shows in one embodiment how a substrate 20 with the functional composite of the first functional layer 21 and the second functional layer 22 can be produced.

[0040] In the embodiment of the Fig.2, the substrate 20 can be, for example, a titanium plate. However, it is also conceivable that the substrate 20 is made of a fiber composite material comprising a fiber material and a matrix material embedding the fiber material, wherein the matrix material of the substrate 20 can already be cured or can be cured together with the first functional layer 21 and the second functional layer 22 in one process step.

[0041] In the area where the functional layers are to be applied to the substrate 20 to form the functional composite, any oxide layer present in this area is first removed. A primer 21a or an adhesion promoter is then applied, onto which the first functional layer 21 is subsequently applied in the form of a film of a thermosetting (epoxy) resin system. The second functional layer 22, which consists of or comprises a thermoplastic material, is then applied to this first functional layer 21, which, in contrast to the second functional layer 22, has a significantly smaller thickness.

[0042] Spacer elements 30 are arranged at the edges, and the structure thus formed is then introduced into a heating press with two parallel plates 31 and cured under pressure and heat.

[0043] After consolidation, the substrate 20 has the desired functional composite of the first and second functional layers, wherein a corresponding functional element made of a thermoplastic can now be applied, produced or arranged on the second functional layer 22 made of a thermoplastic material.

[0044] This makes it possible to apply functional elements made of a thermoplastic material to substrates that are not thermoplastics and would therefore normally have very poor adhesion. List of reference symbols 10 Hybrid component 11 Substrat 12 functional element 20 Substrat 21a Primer 21 first functional layer / thermosetting resin system 22 second functional layer / thermoplastic material 30 spacer elements 31 Heating press

Claims

[1] Method for producing a hybrid component (10) made of at least two different materials, the method comprising the following steps: - providing a substrate (11, 20) made of a substrate material, to which at least one functional element (12) is to be applied in a functional region of the substrate (11, 20), - creating a first functional layer (21) made of a thermosetting resin system (21) on the substrate (11, 20) at least within the functional area of the substrate (11, 20), - applying at least one second functional layer (22) made of a thermoplastic material (22) to the first functional layer (21), - wherein the thermosetting resin system (21) and the thermoplastic material (22) are selected such that both form a material bond after consolidation, and - applying a thermoplastic material different from the substrate material to this second functional layer (22) thus produced on the substrate (11, 20) in order to produce the functional element (12) on the substrate (11, 20), wherein the substrate material is a metal material or contains such a material, wherein before the first functional layer (21) is applied to the metal substrate, the oxide layer of the metal substrate is first removed at least in the functional area and after the oxide layer has been removed and before the first functional layer (21) is applied to the metal substrate, a primer (21a) is applied. [2] Method according to claim 1, characterized by that the first and second functional layers (22) are consolidated before the thermoplastic material for the functional element (12) is applied. [3] Method according to claim 1 or 2, characterized bythat the thermosetting resin system (21) is an epoxy resin system and / or that the thermoplastic material (22) is a PEI, PSU, PES or PA. [4] Method according to one of the preceding claims, characterized by that the thermoplastic material of the second functional layer (22) is applied to the first functional layer (21) in the form of a thermoplastic film. [5] Method according to one of the preceding claims, characterized by that the first functional layer (21) is applied in such a way that the material thickness of the first functional layer (21) is less than 1 mm. [6] Method according to one of the preceding claims, characterized by that the second functional layer (22) is applied in such a way that the material thickness is less than 10 mm. [7] Method according to one of the preceding claims, characterized bythat the functional element (12) is produced on the second functional layer (22) by printing, injection-molding, pressing, welding and / or spraying the thermoplastic material of the functional element (12).

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