Method for producing a metal foam product from an aluminium-containing material with the aid of a tool mould sectionally coated with a release agent, and tool mould

Abstract

The invention relates to a method (100) for producing a metal foam product (1) having a metal foam made of an aluminium-containing material, comprising the method steps (102, 104, 106, 108): providing a tool mould (1000) which has at least one portion (1008) made of a cast aluminium material, wherein the portion delimits at least part of the mould interior (1006) of the tool mould; coating at least some portions of an inner surface (1010), facing the mould interior, of the portion with a release agent (1012); filling the mould interior of the tool mould with the aluminium-containing material and a blowing agent; heating the tool mould with the material and blowing agent located therein, such that the material is foamed. The invention also relates to a tool mould. The method according to the invention and the tool mould according to the invention lead to energy-efficient and uniform heating of the aluminium material in the tool mould.

Description

[0001] Method for producing a metal foam product from an aluminum-containing material using a mold partially coated with a release agent, and mold

[0002] The invention relates to a method for producing a metal foam product from an aluminum-containing material using a mold coated in sections with a release agent, as well as to a mold.

[0003] Metal foam products made from aluminum are becoming increasingly popular because they are resilient, energy-absorbing, and have high thermal conductivity, yet require minimal material input. However, the production of such metal foam products is not easy. The aluminum-containing material is foamed by applying heat using a heat-activated release agent such as Ti2O. This requires a significant heat input that is as uniform as possible across the surface. The heat supplied to the mold should be transferred to the aluminum material and the blowing agent as efficiently and with minimal loss as possible.

[0004] The invention is therefore based on the object of providing a method and a tool mold which effect energy-efficient and uniform heating of the aluminum material in the tool mold.

[0005] This object is achieved according to the invention by a method for producing a metal foam product with a metal foam made of an aluminum-containing material, comprising the method steps:

[0006] Providing a tool mold having at least one section made of a cast aluminum material, wherein the section defines at least a portion of the mold interior of the tool mold; coating at least a portion of an inner surface of the section facing the mold interior with a release agent;

[0007] Filling the interior of the tool mold with the aluminum-containing material and a blowing agent;

[0008] Heating the mold with the material and blowing agent contained therein, so that the material is foamed. This object is further achieved by a mold for producing a metal foam product from an aluminum-containing material, wherein the mold comprises at least one section made of a cast aluminum material with an inner surface that defines a mold interior and is coated with a release agent.

[0009] The advantage of both of these solutions is that the section of cast aluminum material with the lid and / or base of the mold has high thermal conductivity, so that heat input directed at the lid and / or base is evenly distributed across the surface and conducted to the mold interior with minimal loss. Previously, steel was used for the lid and / or base. However, the metal foam can bond to the lid and / or base. To prevent this, a release agent is used. This results in the further advantage that the bond between the lid and / or base can be controlled through the use of the release agent.Therefore, if a metal foam product is desired which has a composite structure at least in sections, i.e. has a cover and / or base layer made of, for example, a plate or another shape in sections, a part of the cover and / or the base may not be coated with a release agent, so that at this point the metal foam and the cover and / or the base form a metallic bond.

[0010] The invention can be further improved by the following features, each of which is advantageous in itself and can be combined with one another in any way. The features described below can be used indiscriminately both to improve the process and to improve the tool shape.

[0011] In one embodiment, the release agent can comprise or consist of boron nitride, graphite, and / or a ceramic, in particular an aluminum oxide or a carbide such as tungsten carbide. These release agents are heat-resistant and reliably prevent bonding between the metal foam and the lid and / or base.

[0012] The mold is preferably reusable or is reused. This reduces manufacturing costs.

[0013] The pot and / or lid can be assembled from individual segments, allowing molds with different geometric shapes to be assembled. The individual segments can be coated with release agents independently of one another. For example, at least one segment can remain uncoated, bonding with the metal foam and becoming part of a composite structure. This segment is, of course, not reusable but is part of the metal foam product.

[0014] The segments can be made of different materials. For example, materials with different thermal conductivities can be used. In this way, the heat input into the mold interior can be influenced by the composition of the segments. This can compensate for uneven heat input, which is determined by the furnace, or specifically influence the structure of the metal foam in individual areas. According to a further embodiment, the segments that become part of the metal foam product because they bond with the metal foam can be made of a different material than the segments that remain in the mold.

[0015] The base can be pot-shaped and, for example, have a raised rim against which the lid rests. Of course, the lid can also be pot-shaped and have a raised rim that rests against the base. Finally, the lid and base can each have an rim that rests against the other element—i.e., the base or the lid. The rim does not have to be continuous. The rim can be formed by individual segments, while other segments have no rim.

[0016] The invention is explained below by way of example with reference to the figures. Subject to the above explanations, individual features described below may also be omitted from the corresponding embodiment if the technical effect of these features is not important for a particular application. Conversely, a feature described above but not described below may also be added to the corresponding embodiment if the technical effect of this feature is important for a particular application.

[0017] They show:

[0018] Fig. 1 is a schematic representation of a metal foam product;

[0019] Fig. 2 is a schematic representation of a process for producing a metal foam product;

[0020] Fig. 3 is a schematic representation of a tool mold for producing a metal foam product; and Fig. 4 is a schematic representation of another tool mold for producing a metal foam product.

[0021] Fig. 1 shows a metal foam product 1 comprising a metal foam 2. The metal foam product 1 can be provided with a cover layer 4 on one or more sides, creating a composite workpiece. The metal foam product 1 can have virtually any three-dimensional shape.

[0022] The cover layer 4 does not have to be applied to a flat side 6 of the metal foam product 1, as shown. A cover layer 4 can alternatively or cumulatively also be arranged on a narrow side 8. The cover layer 4 can, as shown, cover only part of one side of the metal foam 2. It can also cover an entire side.

[0023] There is preferably a metallic bond between a cover layer 4 and the metal foam 2.

[0024] To produce the metal foam product 1, the method 100 schematically illustrated in Fig. 2 is carried out. In a first step 102 of the method 100, a tool mold 1000 is provided. A mold interior 1006 of the tool mold 1000 has the geometric three-dimensional shape that the metal foam 2 has in the metal foam product 1. It should be noted that the metal foam product 1 can be machined or non-machined if necessary for individual applications. For example, the metal foam product 1 can be reshaped to give it a different shape for an application. Alternatively or additionally, the metal foam product 1 can be provided with bores and milled recesses, punchings, and / or additional parts.

[0025] The tool mold comprises, in particular, a cover 1004 and / or a base 1002 made of a cast aluminum material. Base 1002 and / or cover 1004 can be composed of individual segments 1014, as explained in more detail below with reference to Fig. 4. For example, different spatial shapes can be formed from the segments 1014.

[0026] In a second step 104, the lid 1004 and / or the base 1002 is / are coated, at least in sections, with a release agent 1012. The release agent 1012 is, for example, a ceramic, such as aluminum oxide, in particular Al2O3, or a carbide, such as tungsten carbide. Graphite or boron nitride can also be used as the release agent 1012. Where the lid 1004 and / or the base 1002 is coated with a release agent, the metal foam 2 does not bond to the lid 1004 and / or the base 1002. Thus, if, for example, a segment 1014 is not coated with the release agent 1012, it can form a cover layer 4 of the metal foam product 1.

[0027] In step 106, the tool mold 1000 is filled with the aluminum-containing material and a blowing agent. The aluminum-containing material can be in the form of material strips. The blowing agent can be added in the form of strip- or strand-shaped pressed pieces. Filling is simplified if the base 1002 is cup-shaped and, for example, has a raised edge 1003, which, however, does not have to be continuous.

[0028] The mold is then closed by placing the lid 1004 on the base 1002.

[0029] In step 108, the mold 1000 is heated so that the blowing agent is activated and the aluminum-containing material is melted, thereby forming the metal foam 2. Preferably, infrared rays are used to heat the mold 1000.

[0030] The tool mold 1000 is then actively or passively cooled and the finished metal foam product 1 is removed for possible further processing.

[0031] The tool mold 1000 can then be reused unless individual segments 1014 remain as cover layer 4 in the metal foam product 1.

[0032] Fig. 3 shows the tool mold 1000 with a base 1002 and a separate cover 1004, which surround a mold interior 1006 of the tool mold 1000 between them. The tool mold 1000 has at least one section 1008 made of a cast aluminum material, wherein the section 1008 delimits at least a portion of the mold interior 1006. An inner surface 1010 of the base 1002 and / or cover 1004 can be provided at least in sections with a release agent 1012. The base 1002 is provided here, for example, with an edge 1003. The base 1002 and / or the cover 1004 can be made of different materials.

[0033] According to Fig. 4, the base 1002 and / or the cover 1004 can be constructed from individual segments 1014. The segments 1014 can be part of a modular system 1016 that has more segments 1014 than those currently used in the tool mold 1000. Some segments 1014 can be configured with an edge 1003 and some segments 1014 without an edge 1003. Different spatial shapes can be assembled from different segments 1014.

[0034] The segments 1014 can be made of different materials. However, at least one segment 1014 is made of a cast aluminum material. Furthermore, at least one

[0035] Segment 1014 is coated with a release agent. For example, a segment 1014 intended to remain as the cover layer 4 of the metal foam product 1 can be made of steel, while a segment 1014 coated with release agent 1012 can be made of cast aluminum material.

[0036] Reference symbol

[0037] 1 metal foam product

[0038] Metal foam

[0039] Top layer

[0040] Flat side

[0041] 8 Narrow side

[0042] 100 procedures

[0043] 102 first step

[0044] 104 second step

[0045] 106 third step

[0046] 108 fourth step

[0047] 1000 tool mold

[0048] 1002 floor

[0049] 1003 Rand

[0050] 1004 lids

[0051] 1006 mold interior

[0052] Section 1008

[0053] 1010 inner surface

[0054] 1012 Release agent

[0055] 1014 segments

Claims

Claims 1. Method (100) for producing a metal foam product (1) with a metal foam (2) made of an aluminum-containing material, comprising the method steps (102, 104, 106, 108): - Providing a tool mold (1000) having at least one section (1008) made of a cast aluminum material, wherein the section (1008) delimits at least a part of the mold interior (1006) of the tool mold (1000); - at least partially coating an inner surface (1010) of the section (1008) facing the mold interior (1006) with a release agent (1012); - filling the mold interior (1006) of the tool mold (1000) with the aluminum-containing material and a blowing agent; - Heating the tool mold (1000) with the material and blowing agent contained therein so that the material is foamed.

2. Method (100) according to claim 1, wherein the separating agent (1012) - boron nitride; - graphite; - comprises or consists of a ceramic, in particular an aluminium oxide or a carbide such as tungsten carbide.

3. Method (100) according to claim 1 or 2, comprising the following method step: - Reusing the section (1008) of the tool mold (1000) comprising the cast aluminum material.

4. Method (100) according to one of claims 1 to 3, comprising the following method step: - Assembling the tool shape (1000) from individual segments (1014).

5. Tool mold (1000) for producing a metal foam product (1) from an aluminum-containing material, wherein the tool mold (1000) comprises at least one section (1008) made of a cast aluminum material with an inner surface (1010) delimiting a mold interior (1006) and coated with a release agent (1012).

6. Tool mold (1000) according to claim 5, wherein the separating agent (1012) - boron nitride; - graphite; - comprises or consists of a ceramic, in particular an aluminium oxide or a carbide such as tungsten carbide.

7. Tool mold (1000) according to claim 5 or 6, wherein the tool mold (1000) is reusable.

8. Tool mold (1000) according to one of claims 5 to 7, wherein the section (1008) is designed to be assembled from a plurality of segments (1014).

9. Tool mold (1000) according to one of claims 5 to 8, wherein the section (1008) forms at least part of a bottom (1002) and / or a lid (1004) of the tool mold (1000).

10. Tool mold (1000) according to claim 9, wherein the segments (1014) are made of different materials.

11. Tool mold (1000) according to claim 9 or 10, wherein the base (1002) is pot-shaped.