Additive manufacturing of a component made of a metal matrix composite material

Abstract

Method (10) for the additive manufacturing of a component from a metal matrix composite material for a vehicle, the method comprising the following steps: a) providing (12) a plurality of elongated filaments (102); b) providing (14) metal powder (108); and c) additive manufacturing (16) of the metal matrix composite material by melting the metal powder (108) wherein a powder bed (104) of metal powder (108) is provided; wherein at least a portion of the elongated filaments (102) are arranged on the powder bed (104) during additive manufacturing; and wherein in step c) the metal powder (108) is scanned in a scanning direction to create a melt and to bond at least a portion of the elongated filaments (102) together and thereby selectively fuse the metal powder (108) into a desired shape, wherein the powder bed (104) is arranged within a manufacturing device (100); wherein the manufacturing device (100) has at least one opening (112) suitable for receiving the elongated filaments (102); and wherein the elongated filaments (102) are moved along a direction of movement (114) transverse to the scanning direction (110), thereby forming a desired length of the component, wherein at least one of the elongated filaments (102) is a polymer fiber.

Description

Field of the InventionThe present invention relates to the additive manufacturing of components of vehicles. In particular, the invention relates to a method for the additive manufacturing of a component from a metal matrix composite material and to a manufacturing device for carrying out a method for the additive manufacturing of a component from a metal matrix composite material.BACKGROUND OF THE INVENTIONAdditive manufacturing methods, also referred to as "three-dimensional (3D) printing", make it possible to produce, for example, plastic or metallic objects which have been previously designed on the computer in the form of CAD data. Additive manufacturing of a large metallic structural component of a vehicle, such as a bionic rib of an aircraft, can be time-consuming.DE 10 2010 049 195 B4 describes a method for generatively generating a component comprising the layer-by-layer application of a solidifiable material on a construction platform in a production direction. The material is solidified according to a predetermined component geometry, wherein the individual layers bond to form the finished component in the solidification region.US 6 064 031 A describes how the structural assemblies are selectively reinforced with a metal matrix composite in areas susceptible to mechanical defects. More specifically, a channel is milled into a structural member in a region of relatively high voltages. A reinforcing element is inserted into the channel. Metal powder is applied to and around the reinforcing member. The metal powder is irradiated from a high energy source to confine the reinforcing member in a metal matrix and consolidate the metal matrix with the inner surface of the channel. The resulting assembly is lightweight and has improved strength and rigidity at room and elevated temperatures.DE 102 15 999 A1 relates to a method for producing fiber-reinforced semi-finished product in the form of metal strips, metal sheets or the like from at least one fiber layer which comprises a plurality of long to endless reinforcing fibers spaced apart from one another and arranged in parallel and a metal.DE 11 2007 003 090 T5 describes methods for producing a three-dimensionally shaped article by irradiating a metal material with light rays, the method comprising the steps of: an irradiation step of irradiating a metal mesh material formed of metal wires and a metal powder with light rays to form a solidified layer or a molten layer; and a lamination step of forming solidified layers or molten layers by repeatedly carrying out the irradiation step for metal mesh materials and metal powder, wherein before each irradiation step, the metal mesh material and the metal powder are supplied to form a three-dimensionally shaped article.DE 10 2015 211 559 A1 describes an innovative 3D printing method for producing metal components which have integrated glass fibers. The method comprises a plurality of steps: First, a metal modelling material is heated and liquefied. This material is then deposited layer by layer into material layers, followed by curing layer by layer in order to ensure the stability of the structure.SUMMARY OF THE INVENTIONIt is an object of the present invention to provide an improved method and an improved manufacturing device for additive manufacturing of a metallic component of a vehicle.This object is achieved by the subject matters of the independent claims. Exemplary embodiments are evident from the dependent claims and the following description.According to one aspect of the invention, a method for the additive production of a component from a metal matrix composite material is specified. The method may comprise a plurality of steps. In a step a) of the method, a plurality of elongate filaments are provided. In a further step b) of the method, metal powder is provided. Furthermore, in a further step c) of the method, additive manufacturing of the metal matrix composite material is carried out by melting the metal powder.Metal matrix composites may consist of a continuous metal matrix with a discontinuous ceramic or organic reinforcement in its interior, e.g. in the form of fibers or whiskers. Metal matrix composites include, for example, reinforced aluminum, titanium, and also other reinforced metal materials.The term "filament" is understood here as a summary generic term for an elongate, optionally quasi-endless, structure. A filament can also comprise fibers and threads, for example. Depending on the application, the diameter of the filament may vary, for example, between less than one centimeter (e.g., 0.5 centimeter) and several centimeters (e.g., 10 centimeters).The metal powder which can be used in additive manufacturing can be selected appropriately depending on the application. As metal powder, metals such as tool or stainless steel, aluminum or titanium can be used. Further examples are metal alloys, such as wrought aluminum alloys, titanium alloys, and magnesium alloys. The wrought aluminum alloys can be made of, for example, pure aluminum, copper, manganese, silicon, magnesium, zinc, magnesium, and silicon, etc. The titanium alloys are, for example, alpha titanium alloys, beta titanium alloys, alpha beta titanium alloys, titanium aluminides. The magnesium alloys include, for example, magnesium-aluminum-manganese (Mg-Al-Mn), magnesium-aluminum-zinc (Mg-Al-Zn), magnesium-zinc-zirconium (Mg-Zn-Zr), magnesium-rare earth metal-zirconium (Mg-E-Zr), magnesium-rare earth metal-silver-zinc (Mg-E-Ag-Zn) (with or without thorium), magnesium-thorium-zirconium (Mg-Th-Zr).In additive manufacturing, the metal powder just required is completely liquefied, for example by means of a laser. Once cooled, the material solidifies. The component is built up layer by layer: this is done by lowering the build platform, applying metal powder again and again and then melting again. Examples of additive manufacturing methods are, for example, selective laser sintering (SLS), selective laser melting (SLM) and electron beam melting (EBM), also referred to as electron beam melting.By using the elongated filaments, the process can produce a resultant product having controlled and predictable porosity. This can help determine the component behavior and the component properties. Large-format components of a vehicle can also be manufactured by additive manufacturing methods. For example, a desired (theoretically unlimited) length of the component can be formed. In other words, large-format metallic components can also benefit from the advantages of additive manufacturing, such as a significantly greater freedom of design and weight savings, which are important for the aircraft structural components, for example. Furthermore, the production speed can be improved compared to additive manufacturing using only metal powder or wire- or star-shaped construction materials. This can reduce the manufacturing time as well as the manufacturing cost. In additive manufacturing, only a portion of the elongated filaments are melted, so that the total energy requirement can be reduced and the distortion occurring due to thermal reduction can be reduced. It should be noted that the additive manufacturing method can be used not only for structural components of an aircraft, but also for components of ground-bound vehicles, i.e. land vehicles, and watercraft.According to one embodiment of the invention, at least one of the elongated filaments is a metal filament, a metal-coated non-metal filament, a semi-metal filament, or a polymer fiber.A metal filament is, for example, a filament made of different metals, such as, for example, aluminum, titanium, tool steel, etc. The above-mentioned metal alloys can also be used for this purpose. The metal filaments may be made of the same metal material as the metal powder.A non-metal metal filament coated with metal is, for example, a ceramic filament coated with aluminum.A semi-metallic filament is partly made of metals. For example, a semimetal filament contains 30% to 65% metal (steel, iron, copper, brass, etc.) mixed with nonmetal (graphite, fillers and binders, etc.).A polymer fiber is obtained by polymerization, addition or condensation and consists in principle of macromolecules arranged in the form of chains.Structural parts made of different materials can thus be produced with the aid of elongate metallic or at least conductive filaments.According to one embodiment of the invention, a powder bed of metal powder is provided. At least some of the elongated filaments are arranged on the powder bed during additive manufacturing. In step c), the metal powder is scanned in a scanning direction, for example, with a laser beam, in order to create a melt and to connect at least a part of the elongated filaments to one another and thereby fuse the metal powder or a part of the elongated filaments in a targeted manner to a desired shape.According to an embodiment of the invention, the powder bed is arranged within a production device. The production device has at least one opening suitable for receiving the elongated filaments. In additive manufacturing, the elongated filaments are moved along a direction of movement transverse to the scanning direction, thereby forming a desired length of the component.The manufacturing device can be transported to any desired location. The manufacturing device can therefore also be referred to as a mobile manufacturing unit. It is also possible to realize an (theoretically) unlimited length of the component by the elongated filaments movable by the production device.According to an embodiment of the invention, a chemically inert atmosphere is provided within the manufacturing apparatus.Inert gases can be used for this purpose, for example. The inert gases include, for example, nitrogen and all inert gases (helium, neon, argon, krypton, xenon, radon). As a result, the oxygen content within the production device can be reduced or completely replaced, so that corrosion damage is avoided. Further, explosion or propagation of combustion can also be prevented.According to one embodiment of the invention, the additive manufacturing is a laser-based additive manufacturing or an arc-based additive manufacturing.Examples of laser-based additive manufacturing are, for example, selective laser sintering or selective laser melting. For example, the build material, such as metal powder and elongated filaments, is fully melted and deposited at the work piece machining point in selective laser melting. The hardening of the material takes place with the cooling process. As a result, the construction object is constructed in layers.In arc-based additive manufacturing, metal powder and parts of the elongated filaments are sintered layer by layer by means of an electron beam in order to produce the structural body.According to one embodiment of the invention, the elongated filaments have a round or angular cross section.An angular cross section can be triangular, rectangular, diamond-shaped, pentagonal, for example.According to a further aspect of the invention, a production device for the additive production of a component made of a metal matrix composite material which contains a plurality of elongate filaments is specified. The manufacturing apparatus includes a powder bed and a heat source. The powder bed provides metal powder. The heat source is configured to melt the metal powder for additive manufacturing of the component in order to fuse the metal powder with the elongated filaments in a targeted manner to a desired shape.The heat source may be, for example, a laser, such as CO2laser. Instead of a laser, an electron beam or an arc can also be used.With such a manufacturing device, it is possible to manufacture large-sized components of a vehicle and to save the manufacturing time. By using the elongated filaments, a theoretically unlimited length or a desired length of the component can be manufactured. For example, stringers of aircraft can be manufactured by such a manufacturing device.According to an embodiment of the invention, the production device comprises at least one opening suitable for receiving the elongated filaments.Thus, components of a vehicle having a desired length can be manufactured. The take-up of the elongated filaments can be carried out, for example, by the draw-in rollers.According to an embodiment of the invention, the manufacturing device further comprises a manufacturing chamber in which the metal powder is melted and in which a chemically inert atmosphere prevails.The chemically inert atmosphere can at least reduce the corrosion damage.Brief Description of the FiguresExemplary embodiments are described below with reference to the following figures. FIG. 1 shows a flow diagram for a method for the additive manufacturing of a component made of a metal matrix composite material for a vehicle, FIG. 2 is a perspective view showing an example of a manufacturing apparatus, FIG. 3 is a perspective view showing another example of a manufacturing apparatus.DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTSFIG. 1 shows a flow diagram 10 for a method for the additive manufacturing of a component made of a metal matrix composite material for a vehicle. The method comprises a plurality of steps which are described below. However, it should be noted that the method can also comprise further steps which are not explicitly mentioned.In step 12 of the method, a plurality of elongated filaments are provided. At least one of the elongated filaments may be, for example, a metal filament, a metal-coated non-metal filament, a semi-metal filament, or a polymer fiber. In other words, an elongate filament can be manufactured at least partially from metal, such as, for example, tool steel or stainless steel, aluminum or titanium. The cross section of an elongate filament is, for example, round or angular. Depending on the application, the diameter may also vary, such as less than 1 centimeter or several centimeters (such as 5 centimeters).In step 14 of the method, metal powder is provided. Here too, depending on the application, fundamentally different metals are used, such as, for example, tool steel or stainless steel, aluminum or titanium. Metal alloys such as wrought aluminum alloys, titanium alloys, or magnesium alloys may also be used. The metal powder and the elongated filaments may be made of the same metal. The volume ratio between the elongated filaments and the metal powder may also vary depending on the component to be manufactured. In one example, the volume ratio between the elongated filaments and the metal powder may be about 4:1. In another example, the volume ratio between the elongated filaments and the metal powder may be 5:1.In step 16 of the method, additive manufacturing of the metal matrix composite material is carried out by melting the metal powder. The additive manufacturing may be, for example, a laser-based additive manufacturing or an arc-based additive manufacturing. In other words, additive manufacturing methods can be realized by applying the metal in the solid state layer by layer on a carrier medium and solidifying it. The connection can be made by fusion using a laser or by arc welding. The power of the heat source may be adjusted to allow low porosity.By using the elongated filaments, a large-sized member of a vehicle can be manufactured. An example is an aircraft stringer. The production time and production costs can also be saved.Step 12 is also referred to as step a), second step 14 as step b), and third step 16 as step c).FIG. 2 shows a perspective view of an example of a manufacturing apparatus 100 for additive manufacturing of a component made of a metal matrix composite material, which contains a plurality of elongate filaments 102. The manufacturing apparatus 100 comprises a powder bed 104 and a heat source 106. The powder bed 104 provides metal powder 108. The heat source 106 is configured to melt the metal powder 108 to additive manufacture the component to selectively fuse the metal powder 108 to the elongated filaments 102 into a desired shape.The production device can be closed, for example, that is to say the elongate filaments to be produced can be enclosed in the production device during additive production and the produced component can only be removed by the additive production method. It is also possible for the production device to be open. In other words, further elongate filaments to be produced can be introduced into the production device during additive manufacturing and the manufactured component can also be removed in the process. An example of such an open-loop manufacturing apparatus is shown in FIG. 3.In additive manufacturing, at least a portion of the elongated filaments 102 are disposed on the powder bed 104. The metal powder is scanned in a scan direction 110 to create a melt and bond at least a portion of the elongated filaments 102 together, thereby selectively fusing the metal powder 108 into a desired shape.Laser-based additive manufacturing or arc-based additive manufacturing, for example, can be used in this case. In other words, the heat source 106 can be, for example, a laser or an arc. The metal powder may also be fused by other methods.The porosity of the solidified material depends on the amount of energy supplied. Rough classification may be made depending on the use of laser or arc to solidify the metal powder. The power of the heat source may be adjusted to allow low porosity.FIG. 3 is a perspective view of another example of a manufacturing apparatus 100. The manufacturing apparatus 100 includes at least one aperture 112 suitable for receiving the elongated filaments 102.In this way, the elongated filaments 102 can be moved along a movement direction 114 transverse to the scanning direction 110 during additive manufacturing. A desired length of the component is thereby formed. For example, FIG. 3 shows a manufactured component 116.Furthermore, the manufacturing device 100 has a manufacturing chamber 118. In the manufacturing chamber 118, the metal powder is melted and a chemically inert atmosphere prevails. Inert gas, such as nitrogen, may be introduced into the manufacturing chamber 118. In this case, the openings 112 of the production chamber 118 can be closed in an airtight manner. Corrosion damage is thereby avoided.The above-described exemplary embodiments can be combined in different ways. In particular, aspects of the method can also be used for embodiments of the devices and use of the devices, and vice versa.Additionally, it should be noted that "comprising" does not exclude other elements or steps and "a" or "an" does not exclude a plurality. It should also be noted that features or steps that have been described with reference to one of the above exemplary embodiments can also be used in combination with other features or steps of other exemplary embodiments described above. Reference signs in the claims should not be regarded as limiting.

Claims

A method (10) for additive manufacturing of a metal matrix composite component for a vehicle, the method comprising the steps of: a) providing (12) a plurality of elongated filaments (102); b) providing (14) metal powder (108); and c) additive manufacturing (16) the metal matrix composite by melting the metal powder (108), wherein a powder bed (104) of metal powder (108) is provided; wherein at least a portion of the elongated filaments (102) is arranged on the powder bed (104) during additive manufacturing; and wherein in step c), the metal powder (108) is scanned in a scanning direction to create a melt and to bond at least a portion of the elongated filaments (102) together and thereby selectively fuse the metal powder (108) to a desired shape, the powder bed (104) being disposed within a fabrication apparatus (100); wherein the fabrication apparatus (100) has at least one opening (112) suitable for receiving the elongated filaments (102); and wherein the elongated filaments (102) are moved along a direction of movement (114) transverse to the scanning direction (110), thereby forming a desired length of the component, wherein at least one of the elongated filaments (102) is a polymeric fiber.The method of claim 1, wherein a chemically inert atmosphere is provided within the manufacturing apparatus (100).The method according to any of the preceding claims, wherein the additive manufacturing is a laser-based additive manufacturing or an arc-based additive manufacturing.The method of any preceding claim, wherein the elongated filaments (102) have a round or angular cross-section.A manufacturing apparatus (100) for additive manufacturing of a component made of a metal matrix composite material, which contains a plurality of elongate filaments (102), comprising: - a powder bed (104); and - a heat source (106); wherein the powder bed (104) provides metal powder (108); and wherein the heat source (106) is configured to carry out a melt of the metal powder (108) for additive manufacturing of the component in order to fuse the metal powder (108) with the elongate filaments (102) in a targeted manner to a desired shape, wherein at least a part of the elongate filaments (102) is arranged on the powder bed (104) during additive manufacturing; and wherein during additive manufacturing, the metal powder (108) is scanned in a scanning direction to create a melt and bond at least a portion of the elongated filaments (102) together and thereby selectively fuse the metal powder (108) into a desired shape, the powder bed (104) being disposed within the manufacturing apparatus (100); wherein the manufacturing apparatus (100) has at least one opening (112) suitable for receiving the elongated filaments (102); and wherein the elongated filaments (102) are moved along a direction of movement (114) transverse to the scanning direction (110), thereby forming a desired length of the component, wherein at least one of the elongated filaments (102) is a polymeric fiber.The manufacturing apparatus according to claim 5, further comprising: - a manufacturing chamber (118) in which the metal powder (108) is melted and in which a chemically inert atmosphere prevails.

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