METHOD AND DEVICE FOR PRODUCEING A LAYER OF MATERIAL

Abstract

A process for producing a material layer (12) from a first metallic material (14) and a second metallic material (16) is described. The first metallic material (14) and the second metallic material (16) are provided in a process zone, each in a solid state. An energy beam is then directed at a section of the first metallic material (14) to be liquefied. The energy beam is also directed at a section of the second metallic material (16) to be liquefied. Furthermore, the sections to be liquefied are introduced into a common melt bath (44) and mixed. Alternatively, the sections to be liquefied are heated by the energy beam until liquefaction and then mixed.Furthermore, a device for producing a material layer (12) from the first metallic material (14) and from the second metallic material (16) is presented, which is set up to carry out such a process.

Description

The invention relates to a method for producing a material layer from a first metal material and from a second metal material.The invention is also directed to an apparatus for producing a material layer from a first metal material and from a second metal material.Methods in which materials are applied layer by layer are also referred to as additive or generative manufacturing methods. The materials can be provided for this purpose in the form of powder or in the form of wire. Such methods are distinguished in that a three-dimensional component to be produced is assembled close to the final contour from individual volume elements. If, as in the present case, two or more starting materials are processed, one also speaks of multi-material methods. In this context, a metal material is understood to mean a material which comprises a metal. A metal material can thus comprise or consist of a single metal or a single metal alloy. Furthermore, the term metal material also includes composite materials with a metallic matrix, which are also referred to as metal matrix composites (MMC). Filled wires, the jacket of which comprises a metal and the core of which comprises a non-metallic material, for example a ceramic material, are also metal materials. Also, filled wires, the jacket of which comprises a metal and the core of which comprises a metallic material, for example in powder form or as wire, are metallic materials.In the field of multi-material methods, it is also known that only starting materials which are similar with respect to their melting properties can be processed to form a three-dimensional component. This is also referred to as compatibility of the starting materials. In other words, in multi-material methods, the starting materials used cannot be freely combined. Thus, for multi-material methods, only certain combinations of starting materials are available. This also applies in particular to metal materials which are used as starting materials.The object of the present invention is therefore to further develop methods for producing a material layer from a first metal material and a second metal material in such a way that an increased range of metal materials can be combined with one another.The object is achieved by a method for producing a material layer from a first metal material and from a second metal material. The method comprisesproviding the first metal material and the second metal material in a process zone, wherein the first metal material assumes a solid state of aggregation and wherein the second metal material assumes a solid state of aggregation,directing an energy beam onto a section of the first metal material to be liquefied and heating the section of the first metal material to be liquefied by means of the energy beam,directing the energy beam onto a section of the second metal material to be liquefied and heating the section of the second metal material to be liquefied by means of the energy beam, andintroducing the portion to be liquefied of the first metal material and the portion to be liquefied of the second metal material into a common melt bath and mixing the first metal material and the second metal material in the common melt bath or heating the portion to be liquefied of the first metal material and the portion to be liquefied of the second metal material by means of the energy beam until the first metal material and the second metal material are liquefied and mixed.In this method, the energy beam is thus directed in chronological succession, i.e. sequentially, onto a section of the first metal material to be liquefied and onto a section of the second metal material to be liquefied. In this case, the first metal material or the second metal material is heated by means of the energy beam. It is understood that the energy beam is not directed at the second metal material when it is directed at the first metal material. Likewise, the energy beam is not directed at the first metal material when directed at the second metal material. In other words, the energy beam is directed only to a single one of the first metal material and the second metal material at any time and never simultaneously to the first metal material and the second metal material. The focus of the energy beam is not important in this case. That is, the energy beam may be focused on the first metal material when directed toward the first metal material or may be defocusing from the first metal material when directed toward the first metal material. The same applies to the second metal material. That is, the energy beam may be focused on the second metal material when directed to the second metal material or may be defocusing from the second metal material when directed to the second metal material. In order to enable this geometrically, at least those portions of the first metal material and of the second metal material, onto which the energy beam is directed, are arranged next to one another when viewed along a beam direction of the energy beam. In this case, the energy beam can also be directed alternately onto the first metal material and onto the second metal material. By sequentially directing the energy beam onto the first metal material and onto the second metal material, the energy and / or power introduced into the first metal material and into the second metal material by means of the energy beam can be adjusted independently of one another with high precision. This also means that the energy and / or power introduced into the first metal material by means of the energy beam and the energy and / or power introduced into the second metal material by means of the energy beam may be greatly different. This has the consequence that metal materials which have greatly different properties, in particular greatly different melting properties, can be processed to form a component. Consequently, by means of the method according to the invention, metal materials can be processed to form a material layer which previously had not been able to be combined or incompatible. Here, the processing to form the material layer can be carried out according to two alternatives. According to the first alternative, the first metal material and the second metal material are heated by means of the energy beam, but are not directly melted by means of the energy beam. In this alternative, the first metal material and the second metal material are melted by introducing the first metal material and the second metal material into a common melt bath. It is understood that in this context the first metal material and / or the second metal material are heated by means of the energy beam to a temperature which is below the respective melting temperature, but preferably close to the respective melting temperature. According to a second alternative, the first metal material and the second metal material are heated by means of the energy beam until the respective liquefaction, that is to say are melted by means of the energy beam. In this alternative, a liquid bridge is formed between the further existing melt bath and each of the first metal material and the second metal material. The first metal material and the second metal material are thus introduced into the common melt bath via the respective liquid bridge. Consequently, a material layer can be produced which comprises both the first metal material and the second metal material. The production of such material layers is advantageous in particular if the resulting material mixture, alloy or intermetallic compound is difficult to process mechanically and / or if it is not available as starting material.In connection with the method according to the invention, the fact that at least those sections of the first metal material and of the second metal material to which the energy beam is directed are arranged next to one another when viewed along a beam direction of the energy beam is to be understood in such a way that these sections do not overlap when viewed along the beam direction of the energy beam. In a case where the first metal material and the second metal material are provided in the wire form or in the rod form, orientation or orientation of the respective wires or rods is not important.It is understood that three or more metal materials can also be processed to form a component by means of the method according to the invention. In this connection, the energy beam is directed at any one time only to a single one of the metal materials in order to heat it. The energy beam thus jumps back and forth between the three or more metal materials.It is also understood that the method according to the invention can also be carried out multiple times, so that multiple material layers can be produced. The plurality of material layers can be arranged three-dimensionally in such a way that a three-dimensional, multilayer workpiece is produced. The method according to the invention can thus also be referred to as a method for producing a workpiece or component comprising a plurality of material layers.In the context of the present invention, the material layer can be built up on a substrate. The substrate can be a component or a section of a component, for example a section which has been produced by means of the method according to the invention. Alternatively, the substrate may be formed by a carrier different from the component.According to an embodiment, the method comprises setting a first process parameter while the energy beam is directed at the portion of the first metal material to be liquefied. While the energy beam is directed onto the section of the second metal material to be liquefied, a second process parameter is set. The first process parameter and the second process parameter differ here. In this context, the term of setting a process parameter can be understood to mean that the respective process parameter is already set when the energy beam is directed at the section of the first metal material or of the second metal material to be liquefied. The process parameter is thus constant, while the energy beam is directed onto the section of the first metal material or of the second metal material to be liquefied. In addition, the term of setting a process parameter can be understood to mean that a setting of the process parameter is carried out while the energy beam is directed onto the section of the first metal material or of the second metal material to be liquefied. In this context, the process parameter thus changes while the energy beam is directed onto the section of the first metal material or of the second metal material to be liquefied. The first process parameter is in particular a first power parameter of the energy beam. The second process parameter is in particular a second power parameter of the energy beam. In other words, the power of the energy beam is preferably different if it is directed toward the first metal material and if it is directed toward the second metal material. Consequently, the energy and / or power introduced into the first metal material and introduced into the second metal material by means of the energy beam can be adjusted independently of one another. As a result, metal materials can be processed to form a material layer or a workpiece which have greatly different properties, in particular greatly different melting properties. Likewise, the first process parameter may include a first feed parameter describing a feed characteristic for the first metal material. The second process parameter may include a second feed parameter describing a feed characteristic for the second metal material. If the first feed parameter and the second feed parameter are different, the first metal material and the second metal material are thus fed in different ways, for example at different feed speeds. In this way, too, metal materials can be processed to form a material layer or a workpiece which have greatly different properties, in particular greatly different melting properties.In a case where the energy beam is an electron beam, exemplary performance parameters are a current intensity for generating the energy beam and an acceleration voltage.An example of a performance parameter in this context is an irradiation time, i.e. a length of a time period during which the energy beam is directed onto the first metal material or onto the second metal material. In this context, it is also conceivable that a performance parameter of the energy beam changes while the energy beam is directed onto the first metal material or onto the second metal material. For example, a performance parameter may periodically change. In this context, the performance parameter may be expressed as a frequency.The energy beam can be directed onto the section of the first metal material to be liquefied using a first irradiation figure. In addition, the energy beam can be directed onto the section of the second metal material to be liquefied using a second irradiation figure. The first irradiation figure and the second irradiation figure may be different. In this context, an irradiation figure is understood to mean a path on a surface of the first metal material or of the second metal material, along which the energy beam moves while it is directed towards the first metal material or towards the second metal material. A simple example of an irradiation figure is a point or a line. Another example of an irradiation figure is a circle or an ellipse. In this context, the energy beam is thus guided along a circle or along an ellipse on the surface of the first metal material or of the second metal material, while it is directed towards the first metal material or towards the second metal material. Alternatively, an irradiation figure can also comprise two or more nested, for example concentric, circles. An irradiation figure can also be composed of a plurality of points or lines. An alternative term for an irradiation figure is a raster pattern or an oscillation figure. A parameter of an irradiation figure is an irradiation frequency or oscillation frequency. The irradiation frequency or oscillation frequency describes the frequency with which, i.e. how frequently per unit time, an irradiation figure is traversed. In a case where the irradiation figure is composed of a plurality of points or lines, the irradiation frequency or oscillation frequency may also indicate a number of points of the irradiation figure that are approached per unit time. By appropriately selecting an irradiation figure, a power or energy and its local distribution in the first metal material or in the second metal material can be set precisely. If different irradiation figures are selected for the first metal material and the second metal material, it is thus possible to take account of different properties, in particular different melting properties, of the first metal material and of the second metal material and the first metal material and the second metal material nevertheless be processed to form a material layer or to form a workpiece.For example, the energy beam is directed alternately onto the first metal material and the second metal material, wherein at least ten changes are carried out per second. An alternating frequency is thus at least 10 Hz. In other words, the energy beam oscillates between the first metal material and the second metal material. If an alternating frequency of at least 10 Hz is selected, the first metal material and the second metal material can be heated quasi simultaneously by means of the energy beam. In addition, the alternating frequency of at least 10 Hz enables precise and reliable heating.It is noted that in beam-based manufacturing methods, in which the energy beam is alternately directed to a first material and to a second material, the term multi-beam technique is often used. However, strictly speaking, this is not correct, since only a single energy beam is used, but this beam jumps back and forth between the first material and the second material in a manner that gives the impression of two separate beams.According to a variant, the first metal material may be characterized by a first melting parameter. The second metal material may be characterized by a second melting parameter. The first melting parameter and the second melting parameter may be different. Exemplary melting parameters are a melting temperature, a vapor pressure, an evaporation temperature and a melting energy. By sequentially directing the energy beam onto the first metal material and onto the second metal material in time, the different melting parameters can be taken into account when producing the material layer in such a way that the first metal material and the second metal material are present in the material layer in a predefined ratio. In particular, it is thus possible to prevent one of the first metal material and the second metal material from evaporating in an undesired manner. This results in a material layer or a workpiece having the desired material properties.Preferably, an alloy and / or an intermetallic compound is formed during the mixing of the first metal material and the second metal material. In other words, an alloy and / or an intermetallic compound is formed during the production of the material layer. It is also referred to here that the alloy and / or the intermetallic compound is formed "in situ". As already mentioned, material layers of alloys and / or intermetallic compounds can be produced in this way, the components of which in the form of the first metal material and the second metal material have greatly different properties, in particular greatly different melting properties. Furthermore, material layers of alloys and / or intermetallic compounds can be produced in this way, which are not available on the market as starting materials.Thus, for example, the following intermetallic compounds can be produced: aluminides, in particular iron aluminides, titanium aluminides, nickel-based superalloys such as Ni3Al or NiAl, shape memory alloys such as nitinol (NiTi), highly alloyed chromium and chromium nickel steels, or also copper or niobium tin phases.The first metal material and / or the second metal material preferably comprises titanium and / or copper.In one example, the first metal material and / or the second metal material is provided in wire form. Sections of wires are thus heated by means of the energy beam and melted directly or indirectly. Such production methods are also referred to as wire-based additive manufacturing methods. With such methods, three-dimensional workpieces close to the final contour can be produced in a comparatively short time.As already explained, in cases in which the first metal material and / or the second metal material are provided in wire form, an orientation or alignment of the respective wires is not important. In a first preferred embodiment in which both the first metal material and the second metal material are provided in wire form, the respective wires enclose an acute angle. In a second preferred embodiment, the respective wires are provided substantially perpendicular to each other. In a third preferred embodiment, the respective wires are oriented opposite to one another, i.e. enclose an angle of substantially 180°. In a first variant of this embodiment, the wires are oriented along a material application direction or travel direction. Thus, one of the first metal material and the second metal material is provided in a towing manner and the other of the first metal material and the second metal material is in each case provided in a piercing manner. In a second variant of this embodiment, both wires are oriented substantially at right angles to the material application direction or travel direction. In a case where the method for manufacturing a material layer is a welding method, the material application direction may also be referred to as a welding direction.In a further example, in which the first metal material and the second metal material are provided in wire form, these wires may differ not only with regard to the metal material, but also with regard to their diameter and / or cross section. In this way, a ratio of the first metal material to the second metal material in the material layer can be influenced in a simple manner.The method may also include directing the energy beam onto the common melt pool. This means that the energy beam is directed in a time-sequential manner onto the first metal material, the second metal material and the melt bath. In this case, the energy beam can of course also be directed multiple times onto each of the first metal material, the second metal material and the melt bath. In this case, the sequence in which the energy beam is directed in a temporally sequential manner onto the first metal material, the second metal material and the melt bath can always be the same or change during the method. Due to the fact that the energy beam is directed onto the melt bath, a defined energy or power can be introduced into the melt bath. More generally, the molten bath can be controlled by means of the energy beam. This is in particular a temperature of the melt bath. In this way, the mixing of the first metal material and the second metal material and / or a chemical or physical reaction between the first metal material and the second metal material can be influenced, in particular controlled. Thus, a material layer of high quality can be produced.It is understood that the energy beam can be directed to the molten bath using a third irradiation figure. In a preferred example, the energy beam is thus directed onto the first metal material using the first irradiation figure, directed onto the second metal material using the second irradiation figure and directed onto the melt bath using the third irradiation figure. Consequently, the energy or power input into each of the first metal material, the second metal material and the melt bath can be adjusted precisely and reliably, so that a high-quality material layer can be produced.The energy beam may be an electron beam. Such an energy beam has the advantage that it can be aligned with the first metal material, the second metal material and / or the melt bath with the highest precision. Furthermore, such an energy beam has a relatively high energy density. Moreover, it can be changed in its orientation, i.e. deflected, with high speed and precision. The electron beam is thus particularly well suited for the present method, in which it is important to point the energy beam sequentially in time onto the first metal material, the second metal material and optionally also onto the melt bath.In addition, the object is achieved by a device for producing a material layer from a first metal material and from a second metal material. The device is configured to execute a method according to the invention. Such a device is consequently configured to direct the energy beam successively in time, i.e. sequentially, onto a portion of the first metal material to be liquefied and onto a portion of the second metal material to be liquefied. As already mentioned, it is understood that the energy beam is not directed at the second metal material when it is directed at the first metal material. Likewise, the energy beam is not directed at the first metal material when directed at the second metal material. In other words, the device is designed to direct the energy beam at any point in time only to a single one of the first metal material and the second metal material and never simultaneously to the first metal material and the second metal material. In this case, the device can also be designed to direct the energy beam alternately onto the first metal material and onto the second metal material. In order to enable this geometrically, at least those portions of the first metal material and of the second metal material, onto which the energy beam is directed, are arranged next to one another when viewed along a beam direction of the energy beam. By sequentially directing the energy beam onto the first metal material and onto the second metal material, the energy and / or power introduced into the first metal material and into the second metal material by means of the energy beam can be adjusted independently of one another with high precision. This also means that the energy and / or power which is introduced into the first metal material by means of the energy beam and the energy and / or power which is introduced into the second metal material by means of the energy beam can be greatly different. As a result, metal materials can be processed to form a material layer or a workpiece which have greatly different properties, in particular greatly different melting properties. Consequently, by means of the device according to the invention, metal materials can be processed to form a material layer which previously had not been able to be combined or incompatible. Consequently, a material layer can be produced which comprises both the first metal material and the second metal material. The production of such material layers is advantageous in particular if the resulting material mixture, alloy or intermetallic compound is difficult to process mechanically and / or if it is not available as starting material.The invention will be explained below with reference to various exemplary embodiments which are shown in the attached drawings. The following are shown: FIG. 1 shows an apparatus according to the invention for producing a material layer from a first metal material and from a second metal material, by means of which an apparatus according to the invention for producing a material layer from a first metal material and from a second metal material is carried out, FIG. 2 shows a detailed view of a process zone of the apparatus from FIG. 1 along a direction II in FIG. 1, and FIGS. 3 to 5 are views similar to FIG. 2 of alternative embodiments of the device.FIG. 1 shows an apparatus 10 for producing a material layer 12 from a first metal material 14 and a second metal material 16.In the example from FIG. 1, a three-dimensional component 18 is produced from a multiplicity of such material layers 12. It is understood that the material layers 12 shown have only illustrative character.As will be explained in more detail later, the material layers 12 and thus the three-dimensional component 18 consist of titanium aluminide, i.e. an intermetallic compound of titanium and aluminum. This is a material with low density and very good strength and rigidity properties. Titanium aluminide is also suitable for use in high temperature applications with ambient temperatures up to 750°C. An exemplary field of application is gas turbines.The apparatus 10 comprises a vacuum chamber 20 in which a work table 22 is positioned. On an underside of the work table 22, a lifting unit 24 is provided, by means of which the work table 22 can be moved in the vertical direction. Furthermore, the work table 22 can be rotated about the vertical direction and moved within a horizontal plane. Optionally, the work table 22 can be tilted about a horizontal direction.The component 18 is built up on an upper side of the work table 22, so that the work table 22 can also be viewed as a substrate 26 for the layered construction of the component 18.A portion of the interior of the vacuum chamber 20 that is bounded downwardly by the top side of the work table 22 thus represents a build space 28. It is understood that the installation space 28 is also bounded at the top and to the side. These limitations result from limitations of the relative mobility of the work table 22 with respect to feed units 30, 32 to be explained in detail below.The apparatus 10 furthermore comprises a first feed unit 30, which is designed to feed the first metal material 14 into the installation space 28, more precisely into a process zone. In the present case, the first metal material 14 is provided in the form of a wire. The first feed unit 30 can therefore also be referred to as a first wire conveyor.In addition, the apparatus 10 comprises a second feed unit 32 which is designed to feed the second metal material 16 into the installation space 28, more precisely into the process zone. In the example shown, the second metal material 16 is likewise provided in the form of a wire. The second feeding unit 32 can therefore be referred to as a second wire conveyor.The apparatus also comprises a beam generating unit 34, which is designed to generate an energy beam 36. In the illustrated embodiment, the energy beam is an electron beam.In addition, the beam generating unit 34 also comprises a deflection unit 38. The deflection unit 38 comprises a plurality of magnet coils, by means of which the energy beam 36 can be oriented within the installation space 28. This means that the energy beam 36 can be directed selectively to different points within the installation space 28 by means of the deflection unit 38.The device 10 is further configured to carry out a method for producing a material layer 12 from the first metal material 14 and from the second metal material 16.This method is explained below with reference to FIG. 2. FIG. 2 shows a detailed view of a process zone along a direction II in FIG. 1, the material layer 12 being generated from left to right in the illustration according to FIG. 2, which is to be understood purely by way of example.In a first step S 1, the first metal material 14 and the second metal material 16 are provided in the process zone. Both the first metal material 14 and the second metal material 16 assume a solid aggregate state.As already mentioned, both the first metal material 14 and the second metal material 16 are provided in wire form. In FIG. 2, therefore, one end of the wire made of the first metal material 14, i.e. one end of an aluminum wire, and one end of the wire made of the second metal material 16, i.e. one end of a titanium wire, can be seen.Here, the ends of the wires are arranged side by side in the view of FIG. 2 corresponding to a view along a beam direction of the energy beam 36. This means that the ends of the wires do not overlap or touch in this view.The wires enclose an acute angle in the exemplary embodiment of FIG. 2.In a second step S 2, the energy beam 36 is directed by means of the deflection unit 38 onto a section of the first metal material 14 to be liquefied. The portion of the first metal material 14 to be liquefied is substantially the associated wire end.For this purpose, a first irradiation figure 40 is used, which is symbolized by a dashed rectangle in the exemplary embodiment shown. The first irradiation figure 40 includes a path on a surface of the first metal material 14 along which the energy beam 36 is guided while being directed toward the first metal material 14.The energy beam 36 is characterized by a first performance parameter. In the exemplary embodiment shown, the first performance parameter relates to an energy density. For convenience of explanation, this energy density is constant for the entire irradiation figure 40. The energy density therefore does not change while the energy beam 36 is guided along the irradiation figure 40. This can of course be different in other exemplary embodiments.The first metal material 14, more precisely its section to be liquefied, is thus heated by means of the energy beam 36.After the second metal material 16 is arranged along the beam direction next to the first metal material 14, the energy beam 36 is not directed onto the second metal material 16.In a third step S 3, the energy beam 36 is now directed by means of the deflection unit 38 onto a section of the second metal material 16 to be liquefied. The portion of the second metal material 16 to be liquefied is substantially the associated wire end.In this case, a second irradiation figure 42 is used, which is symbolized by a dashed rectangle in the exemplary embodiment shown. The second irradiation figure 42 includes a path on a surface of the second metal material 16 along which the energy beam 36 is guided while being directed toward the second metal material 16.The energy beam 36 is characterized by a second performance parameter. The second performance parameter relates to an energy density in the exemplary embodiment shown. For convenience of explanation, this energy density is constant for the entire irradiation figure 42. The energy density therefore does not change while the energy beam 36 is guided along the irradiation figure 42. This can of course be different in other exemplary embodiments.The second metal material 16, more precisely its section to be liquefied, is thus heated by means of the energy beam 36.In a fourth step S 4, the energy beam 36 is subsequently directed by means of the deflection unit 38 onto a melt pool 44.In this case, a third irradiation figure 46 is used, which is symbolized by a dashed rectangle in the exemplary embodiment shown. The third irradiation figure 46 includes a path on a surface of the molten pool 44 along which the energy beam 36 is guided while being directed toward the molten pool 44.The energy beam 36 is characterized by a third performance parameter. The third performance parameter relates to an energy density in the exemplary embodiment shown. For convenience of explanation, this energy density is constant for the entire irradiation figure 46. The energy density thus does not change while the energy beam is guided along the irradiation figure 46. This can of course be different in other exemplary embodiments.The molten bath 44 is thus maintained at a desired temperature by means of the energy beam 36.In the present method, the first metal material 14, which is aluminum, and the second metal material 16, which is titanium, are processed to form a material layer 12 made of titanium aluminide. The material layer 12 made of titanium aluminide must therefore have a correct stoichiometric ratio of aluminum and titanium.In this case, the fact must be taken into account that the melting parameters of the first metal material 14 and the second metal material 16 differ greatly. The pain parameters relate here to a melting temperature. This is 660° C. for aluminum and 1668° C. for titanium.In order to be able to produce the desired titanium aluminide in the material layer 12, both the first metal material 14 and the second metal material 16 must be liquid. At the same time, evaporation of that metal material having the lower melting temperature, i.e. of the first metal material 14, must be avoided. Otherwise, the correct stoichiometric ratio of aluminum and titanium could not be maintained.This is achieved in the present method in that the first performance parameter, the second performance parameter and the third performance parameter are different. In this case, the second power parameter, i.e. the second energy density of the energy beam 36, is higher than the first power parameter and the third power parameter, i.e. higher than the first energy density and the third energy density of the energy beam 36.In addition, the first power parameter, i.e. the first energy density of the energy beam 36, is higher than the third power parameter, i.e. the third energy density of the energy beam 36.Moreover, the first irradiation figure 40, the second irradiation figure 42 and the third irradiation figure 46 are different.In particular, a path of the energy beam 36 described by the first irradiation figure 40 is shorter than a path described by the second irradiation figure 42. A path described by the third irradiation figure 46 is even shorter than the path described by the first irradiation figure 40.In this way, it is achieved that in a fifth step S 5, both the section of the first metal material 14 to be liquefied and the section of the second metal material 16 to be liquefied are heated by means of the energy beam 36 until liquefaction and can be mixed in the melt bath 44. In this case, so-called liquid bridges are formed between the sections of the wires made of first metal material 14 and second metal material 16 that are present in the solid aggregate state and the melt pool 44. A feed speed is substantially the same.In an alternative embodiment of the fifth step S 5, the sections of the first metal material 14 and of the second metal material 16 to be liquefied are heated by means of the energy beam 36 merely to a temperature below the respective melting temperature. The actual melting only occurs when the sections of the first metal material 14 and the second metal material 16 to be liquefied enter the melting bath 44.In order to be able to produce the entire component 18 from the material layers 12 in the present case, the energy beam 36 is directed onto the first metal material 14, the second metal material 16 and the melt bath 44 in a temporally sequential and alternating manner. This is done periodically. In this case, the energy beam is directed at least ten times to the first metal material 14, at least ten times to the second metal material 16 and at least ten times to the melt bath 44 within a second and uses there the respectively associated first irradiation figure 40, second irradiation figure 42 and third irradiation figure 46, respectively.A position of the work table 22 is adjusted by means of the lifting unit 24 in the course of the construction of the component 18.FIGS. 3 to 5 show alternative embodiments of the apparatus 10, wherein a process zone is shown in each case in a view corresponding to FIG. 2. Accordingly, the method carried out by means of the apparatus 10 for producing the material layer 12 also changes.In the following, only the differences from the embodiment of the device 10 and the method already explained with reference to FIGS. 1 and 2 will be discussed.The differences always relate to the orientation or feed direction of the first metal material 14 provided in the form of a wire and of the second metal material 16 provided in the form of a wire.In the embodiment according to FIG. 3, the ends of the wires face each other, wherein the feed directions of the wires, i.e. of the first metal material 14 and of the second metal material 16, are opposite each other. In the region of the melt bath 44, the wires made of first metal material 14 and second metal material 16 are therefore arranged substantially on a line, the respective ends facing one another.Thus, in the variant from FIG. 3, the first metal material 14 is introduced into the melt bath 44 in a towing manner and the second metal material 16 is introduced in a piercing manner.In the embodiment according to FIG. 4 as well, the wires made of first metal material 14 and second metal material 16 are arranged substantially on a line in the region of the melt bath 44. However, the wires are now oriented perpendicularly with respect to a material application direction or travel direction.A further embodiment is shown in FIG. 5. Here, the wires made of first metal material 14 and second metal material 16 are oriented at right angles to one another. In this case, the second metal material 16 is introduced into the melt bath 44 in a towing manner and the first metal material 14 is introduced laterally.For the rest, reference may be made to the above explanations.List of reference characters10 Device 12 Material layer 14 First metal material 16 Second metal material 18 Component 20 Vacuum chamber 22 Work table 24 Lifting unit 26 Substrate 28 Installation space 30 First feed unit 32 Second feed unit 34 Beam generation unit 36 Energy beam 38 Deflection unit 40 First irradiation figure 42 Second irradiation figure 44 Melt bath 46 Third irradiation figure S 1 First step S 2 Second step S 3 Third step S 4 Fourth step S 5 Fifth step

Claims

Method for producing a material layer (12) from a first metal material (14) and from a second metal material (16), comprising - providing the first metal material (14) and the second metal material (16) in a process zone, wherein the first metal material (14) assumes a solid aggregate state and wherein the second metal material (16) assumes a solid aggregate state (S1), - directing an energy beam (36) onto a section of the first metal material (14) to be liquefied and heating the section of the first metal material (14) to be liquefied by means of the energy beam (36) (S2), - directing the energy beam (36) onto a section of the second metal material (16) to be liquefied and heating the section of the second metal material (16) to be liquefied by means of the energy beam (36) (S3), and introducing the section to be liquefied of the first metal material (14) and the section to be liquefied of the second metal material (16) into a common melt bath (44) and mixing the first metal material (14) and the second metal material (16) in the common melt bath (44) or heating the section to be liquefied of the first metal material (14) and the section to be liquefied of the second metal material (16) by means of the energy beam (36) until the first metal material (14) and the second metal material (16) are liquefied and mixed (S5).Method according to claim 1, further comprising setting a first process parameter, in particular a first power parameter of the energy beam (36), while the energy beam (36) is directed onto the portion of the first metal material (14) to be liquefied, and setting a second process parameter, in particular a second power parameter of the energy beam (36), while the energy beam (36) is directed onto the portion of the second metal material (16) to be liquefied, wherein the first process parameter and the second process parameter differ.Method according to Claim 1 or 2, wherein the energy beam (36) is directed onto the section of the first metal material (14) to be liquefied using a first irradiation figure (40), and wherein the energy beam (36) is directed onto the section of the second metal material (16) to be liquefied using a second irradiation figure (42), wherein the first irradiation figure (40) and the second irradiation figure (42) differ.Method according to one of the preceding claims, wherein the energy beam (36) is directed alternately onto the first metal material (14) and the second metal material (16), wherein at least ten changes are carried out per second.Method according to one of the preceding claims, wherein the first metal material (14) is characterized by a first melting parameter and the second metal material (16) is characterized by a second melting parameter, wherein the first melting parameter and the second melting parameter differ.Method according to one of the preceding claims, wherein an alloy and / or an intermetallic compound is formed during the mixing of the first metal material (14) and the second metal material (16).Method according to one of the preceding claims, wherein the first metal material (14) and / or the second metal material (16) is or are provided in wire form.The method of any preceding claim, further comprising directing the energy beam (36) onto the common melt pool (44) (S4).The method of any preceding claim, wherein the energy beam (36) is an electron beam.Device (10) for producing a material layer (12) from a first metal material (14) and from a second metal material (16), configured to carry out a method according to one of the preceding claims.

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