Hybrid component and method for manufacturing a hybrid component partially designed as a metal matrix composite material

Abstract

The invention relates to a hybrid component with a predetermined area with increased wear protection and a method for manufacturing a hybrid component partially designed as a metal matrix composite material, comprising the steps - Arranging a reinforcement body formed from a ceramic material in a casting mold and - Filling the mold with a molten metallic material to form a component blank using casting techniques. In order to provide a method for manufacturing a component partially designed as a metal matrix composite material, which enables the production of complex hybrid components, it is provided that the reinforcement body is designed and positioned in the casting mold in such a way that, after a shaping hot forming of the component blank into the hybrid component, a predetermined area of ​​the hybrid component is formed from a metal matrix composite material exhibiting increased wear protection.

Description

[0001] The invention relates to a hybrid component with a predetermined area with increased wear protection and a method for manufacturing a hybrid component partially designed as a metal matrix composite material, comprising the steps - Arranging a reinforcement body formed from a ceramic material in a casting mold and - Filling the mold with a molten metallic material to form a component blank using casting techniques.

[0002] For example, in the field of manufacturing lightweight metal components, particularly in automotive engineering, it is already known to reinforce these components—which can be made of aluminum, but also magnesium or titanium—to improve their tribological, mechanical, and thermal resistance. This is achieved by using metal matrix composites, which combine the positive properties of metals with those of ceramic materials and minimize their negative properties. Metal matrix composites are composite materials whose microstructure consists of a metallic alloy and a specifically incorporated reinforcing component.

[0003] The production of a metal matrix composite material can be achieved, for example, by introducing ceramic particles and / or fibers as reinforcing components into the melt of a metallic alloy, which is then cast, resulting in the component having the reinforcing components across its entire cross-section.

[0004] Another method for producing metal matrix composites is the so-called infiltration process. This involves using a porous reinforcement element, produced, for example, via conventional ceramic forming processes such as axial pressing, isostatic pressing, or extrusion. This element is placed in the mold before the casting process. During the infiltration process, which occurs while the mold is being filled, the molten metal penetrates the porous ceramic network of the reinforcement element, solidifies, and forms a composite structure with the reinforcement element. Depending on the positioning of the reinforcement elements, the infiltration process also allows for the production of components that are only partially reinforced in those areas where—based on the intended application—improved material properties are required compared to the rest of the component.

[0005] The requirements for the flawless production of the reinforcement bodies from a ceramic material, as well as the process parameters resulting from the casting process, limit the shaping of the producible hybrid components with partially improved material properties.

[0006] Based on this, the invention aims to provide a method for manufacturing a component partially designed as a metal matrix composite material, which enables the production of complex hybrid components. Furthermore, the invention aims to provide such a hybrid component.

[0007] The invention solves the problem by means of a method with the features of claim 1 and by means of a hybrid component with the features of claim 11. Advantageous embodiments of the method according to the invention are specified in dependent claims 2 to 10. Emerging embodiments of the hybrid component are specified in dependent claims 12 to 14.

[0008] The inventive method for producing a hybrid component partially composed of a metal matrix composite material involves first arranging the reinforcing body, formed from a ceramic material, in a mold. Subsequently, the mold is filled with molten metallic material to cast a component blank. This results in a component blank which, after the molten metal has solidified, consists of a metal matrix composite material in sections, namely in the area of ​​the reinforcing body.

[0009] For the production of complex hybrid components that cannot be manufactured using currently known methods, the inventive method provides that the reinforcement body is designed and positioned in the mold in such a way that, after a forming hot forming of the component blank into the hybrid component, a predetermined area of ​​the hybrid component is formed from a metal matrix composite material, which has improved material properties compared to the rest of the hybrid component, such as increased wear protection.

[0010] The method according to the invention involves hot forming the component blank into a hybrid component with the desired shape. In particular, taking into account the flow behavior of the metallic material and the metal matrix composite during the forming process, the reinforcing body is previously designed and positioned and aligned in the mold such that, after completion of the hot forming process of the component blank into the hybrid component, the latter is formed in the predetermined areas from the metal matrix composite material, which, for example, has increased wear protection.

[0011] The inventive method thus makes it possible to produce hybrid components that cannot currently be manufactured, or cannot be manufactured reliably, using known casting methods with ceramic preforms. According to the inventive method, the reinforcement body is shaped and positioned beforehand, taking into account the specific flow behavior of the metallic material and the metal matrix composite during the hot forming of the component blank into the hybrid component. The shaping of the reinforcement body refers in particular to the determination of its shape, composition, and porosity.

[0012] The method according to the invention makes it possible to produce hybrid components with areas made of a metal matrix composite material that cannot be produced, or at least not reliably, using purely casting-based methods. The design and arrangement of the reinforcing element are determined, among other things, by considering the specific flow behavior of the metallic material as well as the metal matrix composite material formed from the metallic material and the reinforcing element during the hot forming of the component blank to the final shape of the hybrid component. Hot forming further improves the lattice structure and phase progression, particularly the uniformity of the grain composition, recrystallization, and refinement of the grain structure. These changes during hot forming complementarily improve the mechanical properties of the hybrid component.

[0013] Overall, the inventive method thus enables the production of hybrid components that cannot be manufactured using casting techniques or with process reliability, and which feature areas made of a metal matrix composite material with improved material properties. The arrangement, orientation, and design of the reinforcing body in the mold for producing the component blank are carried out taking into account the subsequent hot forming of the component blank into the hybrid component.

[0014] The method according to the invention enables the process-safe, reliable and economical production of hybrid components with increased wear resistance.

[0015] The reinforcing body can be produced, for example, using specially developed or conventional ceramic forming processes such as axial pressing, isostatic pressing, or extrusion. The formation of the metal matrix composite can then be achieved, for example, by infiltration of the reinforcing body with the molten metallic material. According to a further development of the invention, the reinforcing body is produced from a reactive powder mixture of ceramic materials and a moderator.

[0016] According to this embodiment, the powder mixture is preferably compacted to form the reinforcing body. Contact with the molten metallic material during the casting process initiates an exothermic synthesis reaction that partially converts the reactive powder mixture into carbides. The moderator in the powder mixture contains a metallic material, e.g., titanium, which, during the reaction of the powder mixture, forms the matrix of the metal matrix composite that surrounds the carbides. The use of the advantageously provided powder mixture ensures the reliable formation of a metal matrix composite.

[0017] The method according to the invention provides that the reinforcing body is designed taking into account the shape and properties, in particular the extent and position of the area of ​​the hybrid component to be manufactured that is formed from the metal matrix composite material. This also means that the reinforcing body, made of a ceramic material, is adapted, among other things, with regard to its composition and porosity, to the requirements of the manufacturing process of the metal matrix composite during the casting process, e.g., the infiltration process, in order to provide a hybrid component tailored to the respective application. In addition to the use of a single reinforcing body, the use of several reinforcing bodies is also possible, whereby these can also have different properties from one another, e.g., due to different dimensions and / or the use of different materials.This allows for a particularly customized manufacturing of the hybrid component.

[0018] Possible objectives achievable for the hybrid component include, for example, a partial increase in mechanical strength, a localized reduction of friction and wear, a section-by-section improvement in thermal stability, and good processability and load-bearing capacity at the lowest possible manufacturing costs. According to a particularly advantageous embodiment of the invention, the reinforcing body is made of particles, long fibers, short fibers, or whiskers, or a combination thereof, from ceramic materials. The use of one or more of the aforementioned components enables the reinforcement body to be tailored to the hybrid component being manufactured, and the reinforcing body can also be ideally adapted with regard to its flow behavior during hot forming from the component blank to the hybrid component.

[0019] The choice of ceramic materials for manufacturing the reinforcement body is generally unrestricted. However, in a particularly advantageous embodiment, oxide and / or non-oxide ceramics are used for the reinforcement body. The use of oxide ceramics such as aluminum oxide, magnesium oxide, or titanium dioxide, as well as the use of non-oxide ceramics such as titanium carbide, tungsten carbide, and silicon carbide, allows the reinforcement body to be tailored to the specific requirements of the hybrid component being manufactured. The selection also takes into account the forming process that occurs during hot forming, thus ensuring the reliable production of a hybrid component with, for example, wear protection positioned at a predetermined location.

[0020] According to a particularly advantageous embodiment, it is provided that the reinforcing body is manufactured with an open porosity of 25 vol.% to 75 vol.%, so that during the casting process, e.g. the infiltration process, a homogeneous metal matrix composite material is reliably formed.

[0021] According to a further embodiment of the invention, it is provided that the reinforcing body is heated to a temperature above 400°C, preferably above 450°C, particularly preferably above 500°C, before the casting mold is filled with the metallic material, thereby ensuring in a particularly reliable manner that the metallic material, which is present as a metallic melt, penetrates the porous ceramic network, solidifies and forms a homogeneous structure together with the reinforcing body.

[0022] As an alternative to, for example, pressureless infiltration of the reinforcement body, a further development of the invention provides that the metallic material is pressed into the mold under a pressure of at least 50 bar, which in particular enables the reliable production of sections made of metal matrix composite material with small thicknesses.

[0023] The selection of the hot forming process for transforming the component blank into a hybrid component can, in principle, be freely chosen depending on the shape of the hybrid component to be produced. For example, the forming can also be carried out using suitable rolling processes. However, according to a particularly advantageous embodiment of the invention, the component blank is formed into the hybrid component within a forging process. During the forging process, e.g., open forging or die forging, the component blank is formed into the hybrid component in one or more stages, thereby ensuring reliable shaping of the hybrid component with homogeneous properties in both the metal matrix composite area and the other areas formed from the metallic material. Particularly advantageously, the forming takes place after the component blank has been preheated to a temperature of 600°C to 1200°C.This allows for large changes in shape with low forming forces, whereby work hardening during the forming process is constantly reduced due to deformation above the recrystallization temperature.

[0024] Essential to the method according to the invention is that the design and arrangement of the reinforcement body in the mold is carried out taking into account the forming of the casting-produced component blank into the hybrid component. According to a particularly advantageous embodiment of the invention, it is provided that the forming process of the component blank into the hybrid component is simulated using software to determine the position of the reinforcement body in the mold and / or to design it.

[0025] Software-based simulation of the forming process from the component blank to the hybrid component makes it possible to precisely predict the design of the reinforcing element and / or its position within the mold, ensuring that a hybrid component with predefined properties is obtained after the forming process. The simulation software takes into account, among other things, process parameters during the forming process as well as specific information about the reinforcing element, thus enabling a reliable prediction of the hybrid component produced by the forming process. The simulation allows the design of the reinforcing element and / or its position to be predicted software-based depending on the desired hybrid component, so that a predetermined hybrid component with the required properties is reliably produced during the hot forming process following the casting.The simulation allows for cost-effective production of the hybrid component, as otherwise necessary extensive adjustments can be reduced to a minimum.

[0026] The simulation software allows all parameters required for manufacturing the necessary component blank to be determined, starting from the desired hybrid component. These include, among other things, the design and position of the reinforcement body, as well as the shape of the component blank.

[0027] Overall, the software makes it possible to determine in advance the required hot forming process and the design of the component blank with integrated reinforcement body, starting from the hybrid component to be achieved.

[0028] The invention further solves the aforementioned problem by means of a hybrid component with a predetermined area offering enhanced wear protection, which is particularly preferably manufactured according to the inventive method described above or as further developed. A characteristic feature of the hybrid component according to the invention is that it is manufactured from a casting-produced and subsequently hot-formed component blank comprising at least one integrated reinforcing body made of a ceramic material.

[0029] The hybrid component according to the invention is characterized by combining the advantageous mechanical properties of a metallic material with the properties of a metal matrix composite material. Areas subject to increased stress during application of the hybrid component can exhibit higher wear resistance due to the metal matrix composite material. Because of the hot forming process used to manufacture the hybrid component from a blank, it can also have structural forms that would not be possible, or not reliably possible, to produce using a purely casting process. This is because, for example, a positionally stable arrangement of the reinforcing element cannot be guaranteed, or the reinforcing elements cannot be produced in the necessary dimensions.

[0030] According to a particularly advantageous embodiment, the proportion of ceramic material in the area formed by the metal matrix composite with increased wear protection is 35 vol.% to 70 vol.%, thereby achieving, in particular, increased mechanical strength compared to the remaining metallic area.

[0031] According to a further embodiment of the invention, the metal matrix composite material is produced by die-casting infiltration of the reinforcing body and / or a die-casting process with an exothermic reaction. This embodiment makes it possible to reliably form even thin reinforcing bodies into a metal matrix composite material and to position them at a suitable location within the hybrid component by hot forming.

[0032] According to a particularly advantageous embodiment of the invention, it is further provided that the metal matrix composite material comprises oxide and / or non-oxide ceramics, which enable the reinforcement body to be adapted to the intended use of the hybrid component to be manufactured in a particularly reliable manner.

[0033] An embodiment of the invention is explained below with reference to the drawings. The drawings show: Fig. 1 a schematic representation of a molding press with a ceramic material arranged in it for the production of a reinforcement body; Fig. 2 a schematic representation of the reinforcement body; Fig. 3 a schematic representation of a casting mold with the reinforcing body positioned in the casting mold; Fig. 4 a schematic representation of a metallic material placed in the mold; Fig. 5a a first forging stage for forming a component blank into a hybrid component; Fig. 5b a second forging stage to transform the component blank into the hybrid component and Fig. 5c a third forging stage to transform the component blank into the hybrid component.

[0034] An embodiment of the inventive method for manufacturing a hybrid component 1 is described below with reference to the Fig. 1 to 5c described.

[0035] In a first procedural step ( Fig. 1 and Fig. 2) A reinforcement body 3 made of a ceramic material, e.g. titanium carbide or tungsten carbide, is produced, wherein the ceramic material 6 is formed into the reinforcement body 3 by axial pressing in a forming press 4.

[0036] The reinforcement body 3 is then, preferably after prior heating to a temperature of 500°C, placed in a casting mold 2 and positioned ( Fig. 3), wherein the positioning of the reinforcement body 3 in the casting mold 2 takes into account a subsequent forming of a casting-produced component blank 7 to the hybrid component 1.

[0037] Following the positioning of the reinforcement body 3 in the mold 2, the mold 2 is filled with a molten metallic material 5 to form a component blank 7 ( Fig. 4), wherein in the area of ​​the reinforcing body 3 this is infiltrated by the melt and together with the metallic material 5 forms the metal matrix composite material having a penetration structure.

[0038] After cooling and demolding the component blank 7, as well as further preparatory work steps such as deburring and cleaning, the component blank 7 is reheated to a temperature of 600°C to 1,200°C in preparation for the hot forging of the component blank 7 into the hybrid component 1, whereby the component blank 7 is formed into the hybrid component 1 in three forging stages with different lower dies 8a, 8b, 8c and upper dies 9a, 9b, 9c ( Fig. 5a, Fig. 5b, Fig. 5c).

[0039] Following hot forming, the forged hybrid component 1 undergoes heat treatment for tempering.

[0040] The design and subsequent positioning of the reinforcement body 3 in the casting mold 2 is carried out taking into account the previously defined design of the forged hybrid component 1 including the intended positions of the metal matrix composite material.

[0041] Based on the design of the hybrid component 1, the selection of the material for the reinforcement body 3 and its position in the mold 2 is carried out using software, taking into account in particular the material behavior of the metallic material 5 and the metal matrix composite, especially their flow behavior. The software simulation enables cost-effective production of the hybrid component 1.

[0042] The simulation software makes it possible to determine the number, materials and positions for the reinforcement bodies 3 for the casting process in such a way that, during the subsequent hot forming of the component blank 7, the wear-protection-enhancing metal matrix composite material is arranged at the stressed wear position of the hybrid component 1. Reference symbol list 1 hybrid component 2 Casting mold 3 Reinforcing bodies 4 Forming press 5 metallic material 6 ceramic material 7 Component blank 8a, 8b, 8c Lower die 9a, 9b, 9c Upper shaft

Claims

[1] Method for producing a hybrid component partially designed as a metal matrix composite (1) comprising the steps - Arranging a reinforcement body (3) formed from a ceramic material in a casting mold (2) and - Filling the mold (2) with a molten metallic material (5) to form a component blank (7) using casting techniques, characterized by , that the reinforcement body (3) is designed and positioned in the casting mold (2) such that, after a forming hot forming of the component blank (7) to the hybrid component (1), a predetermined area of ​​the hybrid component (1) is formed from a metal matrix composite material having increased wear protection. [2] Method according to claim 1, characterized by , that the reinforcing body (3) is made from a reactive powder mixture of ceramic materials and a moderator. [3] Method according to claim 1 or 2, characterized by, that the reinforcing body (3) is made of particles, long fibers, short fibers and / or whiskers made of ceramic materials. [4] Method according to one or more of the preceding claims, characterized by , that the reinforcing body (3) is made of oxide and / or non-oxide ceramics. [5] Method according to one or more of the preceding claims, characterized by , that the reinforcing body (3) is manufactured with an open porosity of 25 vol.% to 75 vol.%. [6] Method according to one or more of the preceding claims, characterized by that the reinforcing body (3) is heated to temperatures above 400°C, preferably above 450°C, particularly preferably 500°C, before filling the mold (2) with the metallic material (5). [7] Method according to one or more of the preceding claims, characterized by, that the metallic material (5) is pressed into the mold (2) under a pressure of at least 50 bar. [8] Method according to one or more of the present claims, characterized by , that the component blank (7) is transformed into the hybrid component (1) by a forging process. [9] Method according to one or more of the preceding claims, characterized by , that the component blank (7) is heated to a temperature of 600°C to 1,200°C before hot forming. [10] Method according to one or more of the preceding claims, characterized by , that the forming process of the component blank (7) to the hybrid component (1) is simulated using software to determine the position of the reinforcement body (3) in the casting mold (2) and / or to design it. [11] Hybrid component with a predetermined area with increased wear protection, in particular manufactured according to a method according to one or more of claims 1 to 10, characterized by , that the hybrid component (1) is made from a component blank (7) having at least one integrated reinforcement body (3) made of a ceramic material, which was produced by casting and subsequently hot-formed. [12] Hybrid component according to claim 11, characterized by , that the proportion of ceramic material (6) in the area formed by the metal matrix composite with increased wear protection is 35 vol.% to 75 vol.%. [13] Hybrid component according to claim 11 or 12, characterized by , that the metal matrix composite material is produced by die-cast infiltration of the reinforcement body (3) and / or pressure measurement methods with exothermic reaction. [14] Hybrid component according to one or more of claims 11 to 13, characterized by that the metal matrix composite material contains oxide and / or non-oxide ceramics.

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