DE102019219327A1 - Layer construction method and layer construction device for the additive manufacture of at least one component area of a component as well as computer program product and storage medium - Google Patents

Abstract

The invention relates to a layered construction method for the additive manufacture of at least one component region (12) of a component (14), in particular a component (14) of a turbo machine. The layer construction method comprises at least the steps of a) providing at least one reference monitoring data set (50) based on reference false color values (64) recorded by optical tomography of at least one reference component area (60) of a reference component (62) during its additive manufacture and characterizes local intensity maxima (66) of the reference false color values (64), b) applying at least one powder layer of a material (22) to at least one build-up and joining zone (II) of at least one movable building platform (24), c) local solidification of the Material (22) for forming a component layer in that the material (22) is selectively scanned and melted with at least one energy beam (28) along scan lines (40), at least one exposure parameter value of the energy beam (28) depending on the at least one reference Monitoring data set (50) and thereby dependent on at least one of the local Internet Intensity maxima (66) is set, d) lowering the construction platform (24) layer by layer by a predefined layer thickness, and e) repeating steps b) to d) until the component area (12) is completed. The invention further relates to a layer construction device (10) for the additive manufacture of at least one component area (12) of a component (14), a computer program product, a computer-readable storage medium and a component (14) with at least one additively manufactured component area (12).

Description

The invention relates to a layer construction method and a layer construction device for the additive production of at least one component region of a component. The invention further relates to a computer program product, a computer-readable storage medium and a component with at least one additively manufactured component area.

Additive layer construction processes describe processes in which geometric data are determined based on a virtual model of a component or component area to be manufactured, which is broken down into layer data (so-called "slicing"). Depending on the geometry of the model, an exposure or irradiation strategy is determined according to which the selective solidification of a material is to take place. In the layer construction process, the desired material is then deposited in layers and selectively scanned and solidified by means of the at least one energy beam in order to additively build up the desired component area. Different irradiation parameters such as the energy beam power and the exposure speed of an energy beam to be used for solidification are important for the resulting microstructure. The arrangement of so-called scan lines is also important. The scan lines, which can also be referred to as melting traces or exposure vectors, define the paths along which the at least one energy beam scans and melts the material and can generally run linearly or non-linearly. This means that additive or generative manufacturing processes differ from conventional abrasive or primary forming manufacturing methods. Examples of additive manufacturing processes are generative laser sintering or laser melting processes, which can be used, for example, to manufacture components for turbomachines such as aircraft engines. In selective laser melting, thin powder layers of the material or the materials used are applied to a building platform and melted and solidified locally with the aid of one or more laser beams in the area of a build-up and joining zone. Then the building platform is lowered, another layer of powder is applied and locally solidified again. This cycle is repeated until the finished component or the finished component area is obtained. The component can then be further processed if necessary or used without further processing steps. In the case of selective laser sintering, the component is produced in a similar way by laser-assisted sintering of powdery materials. The energy is supplied here, for example, by laser beams from a CO ₂ laser, Nd: YAG laser, Yb fiber laser, diode laser or the like. Electron beam methods are also known in which the material is selectively scanned and solidified by one or more electron beams.

A disadvantage of the known layered construction method is the fact that components manufactured with them often have a comparatively high structural anisotropy, which can lead to different mechanical properties depending on the direction. This in turn can lead to reduced strengths and stiffnesses, which have to be taken into account and compensated for in the component design.

The object of the present invention is to improve a layer construction method and a layer construction device of the type mentioned at the beginning in such a way that it is possible to produce components or component areas with more uniform mechanical properties in different spatial directions. Further objects of the invention consist in specifying a computer program product and a computer-readable storage medium which enable a corresponding control of such a layer construction device. Finally, it is the object of the invention to specify a component with at least one additively manufactured component area with more uniform mechanical properties in different spatial directions.

The objects are achieved according to the invention by a layer construction method with the features of claim 1, by a layer construction device with the features of claim 8, by a computer program product according to claim 10, by a computer-readable storage medium according to claim 11 and by a component according to claim 12. Advantageous refinements with expedient refinements of the invention are specified in the respective subclaims, wherein advantageous refinements of each aspect of the invention are to be regarded as advantageous refinements of the respective other aspects of the invention.

1. a) Bereitstellen zumindest eines Referenz-Überwachungsdatensatzes, welcher auf durch optische Tomographie zumindest eines Referenz-Bauteilbereichs eines Referenz-Bauteils während dessen additiver Herstellung erfassten Referenz-Falschfarbwerten basiert und lokale Intensitätsmaxima der Referenz-Falschfarbwerte charakterisiert;
2. b) Auftragen von mindestens einer Pulverschicht eines Werkstoffs auf mindestens eine Aufbau- und Fügezone mindestens einer bewegbaren Bauplattform;
3. c) lokales Verfestigen des Werkstoffs zum Ausbilden einer Bauteilschicht, indem der Werkstoff mit wenigstens einem Energiestrahl entlang von Scanlinien selektiv abgetastet und aufgeschmolzen wird, wobei wenigstens ein Belichtungsparameterwert des Energiestrahls in Abhängigkeit von dem zumindest einen Referenz-Überwachungsdatensatz und dadurch in Abhängigkeit von zumindest einem der lokalen Intentsitätsmaxima eingestellt wird;
4. d) Schichtweises Absenken der Bauplattform um eine vordefinierte Schichtdicke; und
5. e) Wiederholen der Schritte b) bis d) bis zur Fertigstellung des Bauteilbereichs.

Dies ist von Vorteil, da somit der wenigstens eine Belichtungsparameterwert in Abhängigkeit von den Referenz-Falschfarbwerten eingestellt werden kann, wodurch Informationen aus der optischen Tomographie des Referenz-Bauteilbereichs und zusätzlich oder alternativ des Referenz-Bauteils herangezogen werden können, um anhand dieser Informationen den wenigstens einen Belichtungsparameterwert einzustellen. Anhand der Referenz-Falschfarbwerte können während der additiven Herstellung entstehende, unterschiedlich stark erwärmte Zonen des Referenz-Bauteilbereichs bzw. des Referenz-Bauteils detektiert werden. Die optische Tomographie gestattet es beispielsweise warme von kalten Zonen der unterschiedlich stark erwärmten Zonen zu unterscheiden. Die Intensitätsmaxima können dabei jeweils die wärmsten Zonen charakterisieren. So kann dementsprechend ein oberstes Intensitätsmaximum der Intensitätsmaxima die wärmste Zone charakterisieren. Zudem liegt der Erfindung die Erkenntnis zugrunde, dass den warmen und kalten Zonen auch jeweils unterschiedliche Referenz-Gefügestrukturen, also Gefügestrukturen des Referenz-Bauteilbereichs und zusätzlich oder alternativ des Referenz-Bauteils, zugeordnet sein können. Eine warme Zone kann beispielsweise durch längere Energiestrahlbeaufschlagung, welche beispielsweise durch Laserbestrahlung erfolgen kann, entstehen, wohingegen eine im Vergleich dazu kalte Zone durch entsprechend kürzere Energiestrahlbeaufschlagung entstehen kann. Die Dauer der Energiestrahlbeaufschlagung kann jedoch die Referenz-Gefügestruktur maßgeblich beeinflussen, sodass bei längerer Energiestrahlbeaufschlagung (und entsprechend warmer Zone) größere Werkstoffkörner sowie eine größere Gefügeanisotropie auftreten können, als bei kürzerer Energiestrahlbeaufschlagung (kalte Zone). Dementsprechend können über die Referenz-Falschfarbwerte auch Informationen über die jeweilige, von den entsprechenden Zonen abhängige Referenz-Gefügestruktur in die Einstellung des wenigstens einen Belichtungsparameterwertes des Energiestrahls einfließen. Dies ermöglicht es beispielsweise größere, durch den Energiestrahl bewirkte Temperaturunterschiede an voneinander verschiedenen Stellen des Bauteilbereichs zu vermeiden, wodurch dementsprechend beispielsweise Gefügeanisotropieunterschiede zwischen den verschiedenen Stellen gering gehalten werden können und der Bauteilbereich dementsprechend mit gleichmäßigeren mechanischen Eigenschaften in unterschiedlichen Raumrichtungen erstellt werden kann, als beispielsweise der Referenz-Bauteilbereich. Die Referenz-Falschfarbwerte können beispielsweise als Referenz-Grauwerte ausgebildet sein.A first aspect of the invention relates to a layered construction method for the additive manufacture of at least one component region of a component, in particular a component of a turbo machine, comprising at least the following steps:

1. a) providing at least one reference monitoring data set which is based on reference false color values detected by optical tomography of at least one reference component region of a reference component during its additive manufacture and characterizes local intensity maxima of the reference false color values;
2. b) applying at least one powder layer of a material to at least one build-up and joining zone of at least one movable building platform;
3. c) local solidification of the material to form a component layer by the material is selectively scanned and melted with at least one energy beam along scan lines, at least one exposure parameter value of the energy beam depending on the at least one reference monitoring data set and thereby depending on at least one of the local intensity maxima is set;
4. d) Lowering the construction platform layer by layer by a predefined layer thickness; and
5. e) Repeating steps b) to d) until the component area is completed.

This is advantageous because the at least one exposure parameter value can thus be set as a function of the reference false color values, whereby information from the optical tomography of the reference component area and additionally or alternatively the reference component can be used to determine the at least set an exposure parameter value. On the basis of the reference false color values, zones of the reference component area or the reference component that are produced during the additive manufacturing and heated to different degrees can be detected. Optical tomography makes it possible, for example, to distinguish between warm and cold zones in the zones that are heated to different degrees. The intensity maxima can characterize the warmest zones. Accordingly, an uppermost intensity maximum of the intensity maxima can characterize the warmest zone. In addition, the invention is based on the knowledge that the warm and cold zones can also each be assigned different reference microstructures, that is to say microstructures of the reference component area and additionally or alternatively of the reference component. A warm zone can arise, for example, through longer exposure to energy beams, which can be effected, for example, by laser irradiation, whereas a zone that is cold in comparison thereto can arise through correspondingly shorter exposure to energy beams. The duration of the application of the energy beam can, however, have a decisive influence on the reference microstructure, so that larger material grains and a greater structural anisotropy can occur with longer exposure to the energy beam (and correspondingly warm zone) than with shorter exposure to the energy beam (cold zone). Correspondingly, information about the respective reference microstructure dependent on the corresponding zones can also flow into the setting of the at least one exposure parameter value of the energy beam via the reference false color values. This makes it possible, for example, to avoid greater temperature differences caused by the energy beam at different points in the component area, which means that, for example, structural anisotropy differences between the various points can be kept low and the component area can accordingly be created with more uniform mechanical properties in different spatial directions than, for example Reference part area. The reference false color values can for example be designed as reference gray values.

In addition, the reference false color values can be used to identify, for example, respective defects and thus defective structural areas of the reference component area and additionally or alternatively of the reference component. These defects (defective structural areas) can be present in several layers of the reference component area or the reference component and can be detected on the basis of the reference false color values. In the present layer construction method, by setting the at least one exposure parameter value as a function of the reference monitoring data set, it can be avoided that the respective defects occurring in the reference component area or reference component also occur in the component area or the component. This also contributes in an advantageous manner to the design of the component area or the component with more uniform mechanical properties in different spatial directions compared to the reference component area or the reference component.

In an advantageous development of the invention, the at least one reference monitoring data set characterizes a reference structural structure distribution at least in the reference component area and at least one reference exposure parameter value assigned to the reference structural structure distribution. The reference structural structure distribution can be understood to mean a distribution of different structural structures in the reference component area and additionally or alternatively in the reference component. By assigning the at least one reference exposure parameter value to the reference microstructure distribution, it is advantageously possible to create a direct relationship between the reference exposure parameter value and the reference microstructure distribution. This allows a particularly targeted setting of the exposure parameter value in order to achieve a particularly desired, in particular homogeneous, structural distribution in the component area.

This is based on the knowledge that the reference structure distribution depends on the reference exposure parameter value. The reference exposure parameter value can, for example, correspond to a reference energy input into the reference component area as a result of the application of an energy beam or an energy beam power, that is to say a power of the energy beam. For example, it has generally been shown that with a higher reference energy input based on the energy beam in partial areas of the reference component area, a greater structural anisotropy and thus larger material grains also occur in these partial areas, with the partial areas of the reference component area with a higher reference energy input also correspondingly higher reference false color values determined by optical tomography, for example in the form of higher gray values, can be recognized, in particular quantified. The higher the reference false color values (for example reference gray values), the greater the corresponding material grains or the corresponding structural anisotropy in the reference component area or in the reference component as a result of the reference energy input.

In a further advantageous development of the invention, depending on the reference structure distribution and the at least one reference exposure parameter value, at least one correction value is determined by which the at least one exposure parameter value is set differently from the at least one reference exposure parameter value, whereby at least the component area with a Structural structure distribution is provided, which has a lower defect density and / or a lower number of defects than the reference microstructural structure distribution. In other words, the exposure parameter value can differ from the reference exposure parameter value by the correction value. A particularly targeted reduction in the defect density, in other words a density of defects and additionally or alternatively the number of defects, in other words a number of defects, can thereby advantageously take place. Such defects can be designed as defective structural areas, for example as pores or cracks.

In a further advantageous development of the invention, an energy input of the at least one energy beam is set as the at least one exposure parameter value. This is advantageous because by adjusting the energy input a particularly direct influencing of a microstructure in the component layer and thus in the component area of the component can take place. The energy input can have the unit J / mm ³ and thus indicate an input of energy per unit volume.

In a further advantageous development of the invention, in step c) a monitoring data set based on optical tomography of at least the component layer is created, which is compared with the reference monitoring data set to monitor the additive manufacturing of at least the component area. This is advantageous because pores and, additionally or alternatively, cracks can already be recognized during the additive manufacturing of the component area. The monitoring data set can include false color values recorded by optical tomography during the additive manufacturing of at least the component area. The monitoring can take place in that the false color values are compared with the reference false color values. This makes it possible to recognize if, for example, one of the false color values deviates by an impermissibly large amount from a corresponding reference false color value, which can indicate the presence of pores, cracks or other defects. Like the reference false color values, the false color values can be embodied as gray values, for example. Using the false color values, for example, respective defects and thus defective structural areas of the component area and additionally or alternatively of the component can be recognized at an early stage. These defects (defective structural areas) can be present in several component layers of the component area or the component and can be recognized on the basis of the false color values, in particular by comparing the false color values with the reference false color values. A preferred, layer-by-layer comparison of the false color values with the reference false color values advantageously enables a particularly early and particularly precise assessment of whether, for example, rejects are produced when the component region or the component is produced. In addition, based on the layer-by-layer comparison of the false color values with the reference false color values, the at least one exposure parameter value can be changed in layers, so that the exposure parameter value is set differently, so to speak, in different component layers of the component area. This makes it possible to build up further component layers with fewer defects on a particularly defective component layer in order to avoid rejects being produced during the production of the component region.

In a further advantageous development of the invention, a laser beam is used as the energy beam in step c). This is advantageous since the laser beam enables particularly targeted local solidification of the material.

In a further advantageous development of the invention, at least a material from the group of steel, aluminum alloys, titanium alloys, cobalt-based alloys, chromium-based alloys, nickel-based alloys, copper alloys, intermetallic alloys or any mixture thereof is used. Although the material can in principle also be a plastic such as ABS, PLA, PETG, nylon, PET, PTFE or the like, components or component areas with higher mechanical, thermal and chemical resistance can generally be produced with the help of metallic and / or intermetallic materials . For example, the material can contain elements from the iron, titanium, nickel, chromium, cobalt, copper, aluminum or titanium group. The material can be an alloy from the group consisting of steel, aluminum alloy, titanium alloy, cobalt alloy, chromium alloy, nickel-based alloy or copper alloys. For example, the material can be a high temperature-resistant nickel-based alloy such as Mar M-247, Inconel 718 (IN718), Inconel 738 (IN738), Waspaloy or C263. Intermetallic alloys such as Mg ₂ Si and titanium aluminides can also be provided.

• - mindestens eine Pulverzuführung zum Auftrag von mindestens einer Pulverschicht eines Werkstoffs auf mindestens eine Aufbau- und Fügezone mindestens einer bewegbaren Bauplattform;
• - mindestens eine Strahlungsquelle zum Erzeugen wenigstens eines Energiestrahls zum schichtweisen und lokalen Verfestigen des Werkstoffs durch selektives Abtasten und Aufschmelzen des Werkstoffs entlang von Scanlinien; und
• - eine Steuereinrichtung, welche dazu ausgebildet ist:
• - die Pulverzuführung so zu steuern, dass diese mindestens eine Pulverschicht des Werkstoffs auf die Aufbau- und Fügezone der Bauplattform aufträgt; und
• - die Bauplattform so zu steuern, dass diese schichtweise um eine vordefinierte Schichtdicke abgesenkt wird.

Gemäß der Erfindung ist vorgesehen, dass die Steuereinrichtung dazu eingerichtet ist, die Strahlungsquelle anzusteuern und dadurch wenigstens einen Belichtungsparameterwert des Energiestrahls in Abhängigkeit von zumindest einem Referenz-Überwachungsdatensatz einzustellen, wobei der zumindest eine Referenz-Überwachungsdatensatz auf durch optische Tomographie zumindest eines Referenz-Bauteilbereichs eines Referenz-Bauteils während dessen additiver Herstellung erfassten Referenz-Falschfarbwerten basiert und lokale Intensitätsmaxima der Referenz-Falschfarbwerte charakterisiert, wobei die Steuereinrichtung dazu eingerichtet ist, den wenigstens einen Belichtungsparameterwert des Energiestrahls in Abhängigkeit von zumindest einem der lokalen Intensitätsmaxima einzustellen. Die Schichtbauvorrichtung kann beispielsweise eine Kamera, insbesondere Wärmebildkamera, umfassen, mittels welcher die Referenz-Falschfarbwerte des Referenz-Bauteilbereichs des Referenz-Bauteils erfasst werden können. Weitere Merkmale und deren Vorteile sind den Beschreibungen des ersten Aspekts der Erfindung zu entnehmen, wobei vorteilhafte Ausgestaltungen des ersten Aspekts der Erfindung als vorteilhafte Ausgestaltungen des zweiten Aspekts der Erfindung anzusehen sind. Umgekehrt sind vorteilhafte Ausgestaltungen des zweiten Aspekts der Erfindung als vorteilhafte Ausgestaltungen des ersten Aspekts der Erfindung anzusehen.A second aspect of the invention relates to a layer construction device for the additive production of at least one component region of a component by an additive layer construction method, comprising:

• - At least one powder feed for applying at least one powder layer of a material to at least one build-up and joining zone of at least one movable building platform;
• - At least one radiation source for generating at least one energy beam for layer-by-layer and local solidification of the material by selective scanning and melting of the material along scan lines; and
• - a control device which is designed to:
• - to control the powder supply so that it applies at least one powder layer of the material to the construction and joining zone of the construction platform; and
• - to control the building platform so that it is lowered layer by layer by a predefined layer thickness.

According to the invention it is provided that the control device is set up to control the radiation source and thereby set at least one exposure parameter value of the energy beam as a function of at least one reference monitoring data set, the at least one reference monitoring data set being based on at least one reference component area by optical tomography Reference component is based on reference false color values detected during its additive production and characterizes local intensity maxima of the reference false color values, the control device being set up to set the at least one exposure parameter value of the energy beam as a function of at least one of the local intensity maxima. The layer construction device can for example comprise a camera, in particular a thermal imaging camera, by means of which the reference false color values of the reference component area of the reference component can be recorded. Further features and their advantages can be found in the descriptions of the first aspect of the invention, with advantageous refinements of the first aspect of the invention being regarded as advantageous refinements of the second aspect of the invention. Conversely, advantageous configurations of the second aspect of the invention are to be regarded as advantageous configurations of the first aspect of the invention.

In an advantageous development of the invention, the layer construction device is designed as a selective laser sintering and / or melting device. In this way, component areas and complete components can be produced whose mechanical properties are at least essentially direction-independent. For example, CO2 lasers, Nd: YAG lasers, Yb fiber lasers, diode lasers or the like can be provided to generate a laser beam as the energy beam. It can also be provided that two or more electron and / or laser beams are used as the respective energy beams.

A third aspect of the invention relates to a computer program product, comprising instructions which, when the computer program product is executed by a control device of a layer construction device according to the second aspect of the invention, cause the layer construction device to execute the layer construction method according to the first aspect of the invention. A fourth aspect of the invention relates to a computer-readable storage medium comprising instructions which, when executed by a control device of a layer construction device according to the second aspect of the invention, cause the layer construction device to carry out the layer construction method according to the first aspect of the invention.

The present invention may be implemented using a computer program product comprising program modules accessible from a computer usable or computer readable medium and storing program code used by or in connection with one or more computers, processors, or instruction execution systems of a layering device. For the purposes of this description can a computer-usable or computer-readable medium can be any device that can contain, store, communicate, distribute, or transport the computer program product for use by or in connection with the instruction execution system or layered device. The medium can be an electronic, magnetic, optical, electromagnetic, infrared or semiconductor system or a propagation medium per se, since signal carriers are not included in the definition of the physical, computer-readable medium. These include semiconductor or solid-state memory, magnetic tape, removable computer diskette, random access memory (RAM), read-only memory (ROM), rigid magnetic disk, and an optical disk such as read-only memory (CD-ROM, DVD , Blue-Ray etc.), or a writable optical disc (CD-R, DVD-R). Processors as well as program code for implementing the various aspects of the invention can be centralized or distributed (or a combination thereof).

A fifth aspect of the invention relates to a component, in particular a turbine component of a turbomachine, comprising at least one component area which is produced by means of a layer construction device according to the second aspect of the invention and / or by means of a layer construction method according to the first aspect of the invention. As a result, the component according to the invention has a highly uniform and at least essentially direction-independent microstructure, which leads to a significantly higher resistance to cyclic loads and to significantly increased strength and rigidity values. The features resulting therefrom and their advantages can be found in the descriptions of the first and second aspects of the invention, with advantageous configurations of each aspect of the invention being regarded as advantageous configurations of the other aspects of the invention. The component can be designed as a turbine blade for a gas turbine, in particular for an aircraft engine.

• 1 eine schematische Schnittansicht einer Schichtbauvorrichtung;
• 2 eine schematische Darstellung einer Schichtoberfläche eines Referenz-Bauteilbereichs eines Referenz-Bauteils während dessen additiver Herstellung, wobei durch optische Tomographie ermittelte Referenz-Falschfarbwerte der Schichtoberfläche gezeigt sind;
• 3 eine schematische Darstellung einer Schichtoberfläche eines Bauteilbereichs eines Bauteils während dessen additiven Herstellens, wobei durch optische Tomographie ermittelte Falschfarbwerte der Schichtoberfläche gezeigt sind;
• 4 eine schematische Detailansicht eines Oberflächensegments innerhalb eines in 2 umrahmten Bereichs A;
• 5 eine schematische Detailansicht eines weiteren Oberflächensegments innerhalb eines in
• 2 umrahmten Bereichs B;
• 6 ein Gefügeschliffbild, welches eine Referenz-Gefügestruktur des Referenz-Bauteilbereichs zeigt; und
• 7 ein weiteres Gefügeschliffbild, welches eine weitere Referenz-Gefügestruktur des Referenz-Bauteilbereichs zeigt.

Further features of the invention emerge from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respectively specified combination, but also in other combinations, without falling within the scope of the invention leave. There are thus also embodiments of the invention to be considered as encompassed and disclosed, which are not explicitly shown and explained in the figures, but emerge from the explained embodiments and can be generated by separate combinations of features. Designs and combinations of features are also to be regarded as disclosed, which therefore do not have all the features of an originally formulated independent claim. In addition, designs and combinations of features, in particular through the statements set out above, are to be regarded as disclosed which go beyond the combinations of features set forth in the back references of the claims or differ from them. It shows:

• 1 a schematic sectional view of a layer construction device;
• 2 a schematic representation of a layer surface of a reference component region of a reference component during its additive production, with reference false color values of the layer surface determined by optical tomography being shown;
• 3 a schematic representation of a layer surface of a component region of a component during its additive manufacturing, with false color values of the layer surface determined by optical tomography being shown;
• 4th a schematic detailed view of a surface segment within an in 2 framed area A. ;
• 5 a schematic detailed view of a further surface segment within an in
• 2 framed area B. ;
• 6th a micrograph showing a reference microstructure of the reference component area; and
• 7th Another micrograph showing a further reference microstructure of the reference component area.

1 shows a schematic sectional view of a layer construction device 10 . The layer building device 10 serves for the additive manufacturing of at least one component area 12 of a component 14th through an additive layer construction process. The layer building device 10 comprises at least one powder feed 16 with a powder container 18th and a coater 20th . The powder feed 16 is used to apply at least one powder layer of a material 22nd on a build-up and joining zone II one according to the arrow B. movable build platform 24 . This is done by the coater 20th according to arrow III moved to material 22nd from the powder container 18th to the build-up and joining zone II to transport. The layer building device 10 furthermore comprises at least one radiation source 26th for generating at least one energy beam 28 , for example in the form of a laser beam, to consolidate the material in layers and locally 22nd by the material 22nd With the energy beam 28 along from in 2 and 3 strongly schematically indicated scan lines 40 is selectively scanned and melted. In addition, there is a control device 30th provided, which is designed to feed the powder 16 control so that there is at least one powder layer of the material 22nd on the build-up and joining zone II the build platform 24 applies and the build platform 24 layer by layer by a predefined layer thickness according to the arrow B. lowers. Furthermore, the layer construction device comprises 10 an optical device 32 , by means of which the energy beam 28 over the build-up and joining zone II can be moved. The radiation source 26th and the facility 32 are with the control device 30th coupled for data exchange. Furthermore, the layer construction device comprises 10 a heater 34 , by means of which the powder bed can be tempered to a desired base temperature. The heating device 34 can for example comprise one or more induction coil (s). Alternatively or additionally, other heating elements, for example IR radiators or the like, can also be provided.

The control device 30th is set up for this, the radiation source 26th to control and thereby at least one exposure parameter value of the energy beam 28 as a function of at least one reference monitoring data record 50 adjust. The reference monitoring record 50 is based on at least one reference component area through optical tomography 60 of a reference component 62 reference false color values recorded during its additive manufacturing 64 as in 2 are recognizable. In addition, the reference monitoring data set characterizes 50 local intensity maxima 66 the reference false color values 64 . The control device 30th is also set up to include the at least one exposure parameter value of the energy beam 28 as a function of at least one of the local intensity maxima 66 adjust. The reference monitoring record 50 can in a memory of the control device 30th and thus for the additive manufacturing of the component area 12 of the component 14th can be provided by the additive layer construction process. The reference component area can preferably 60 and the component area 12 be congruent to each other. The reference component 62 and the component 14th be congruent to each other. The layer building device 10 in the present case includes a camera 36 , in particular thermal imaging camera, by means of which the reference false color values 64 can be captured. The camera 36 is with the control device 30th coupled for data exchange.

2 shows a schematic representation of a layer surface of the reference component area 60 and thus at least part of the reference component 62 during its additive manufacturing based on the layer construction device 10 . In addition, in 2 using the camera 36 Reference false color values determined by optical thermography 64 as well as the various local intensity maxima 66 the reference false color values 64 recognizable.

The reference monitoring record 50 characterizes a reference structure distribution in the entire reference component 62 as well as in the reference component area 60 . In addition, the reference monitoring data set characterizes 50 at least one reference exposure parameter value assigned to the reference structure distribution. The reference exposure parameter value can correspond, for example, to an energy input which is caused by the energy beam 28 can be effected to the reference component 62 from the material 22nd in the additive manufacturing of the reference component 62 to manufacture. The energy input can also be referred to as energy input. Furthermore, the energy can be introduced as a function of location and additionally or alternatively as a function of the geometry.

The control device 30th is also set up to determine at least one correction value as a function of the reference structure distribution and the at least one reference exposure parameter value. The at least one exposure parameter value is then set to deviate from the at least one reference exposure parameter value by the at least one correction value, whereby at least the component area 12 is provided with a structure distribution which has a lower defect density and / or a lower number of defects than the reference structure distribution.

3 shows the layer surface of the component area in a schematic representation 12 and thus at least part of the component 14th during its additive manufacturing through the layer construction process. In 3 are also respective, based on the camera 36 false color values determined by optical thermography 74 recognizable. Just like the reference false color values 64 are also the false color values 74 using the camera 36 recorded and stored in layers. So is based on the false color values 74 and thus the monitoring data set based on optical tomography of the various component layers 70 created, which for monitoring the additive manufacturing of at least the component area 12 with the reference monitoring data set 50 is compared. The monitoring record 70 is in the memory of the control device 30th saved.

From the synopsis of 2 and 3 it can be seen that during the production of the component area 12 (please refer 3 ) a much more even energy input by means of the energy beam 28 occurs than during the production of the reference component area 60 (please refer 2 ).

4th and 5 each show schematic detailed views of various surface segments of the reference component area 60 . 4th shows an enlarged view of an in 2 bordered area A. , whereas 5 an enlarged view of an in 2 outlined area B. shows. In the area A. During additive manufacturing, a greater amount of energy was introduced using the energy beam 28 , being in the area A. one of the intensity maxima 66 can be seen. Accordingly is in the area A. a greater number of defects 76 (Number of defects) in the form of pores and cracks and a greater density of defects 76 (Defect density) recognizable as in the area B. , as from the synopsis of 4th and 5 emerges.

6th shows a micrograph of the in 5 area shown B. , whereas 7th another micrograph of the in 4th area shown A. shows. In the 6th and 7th The representations shown can be obtained, for example, by electron backscattering (EBSD). From the synopsis of 6th and 7th it can be seen that a lower energy input leads to lower reference false color values 64 as well as too small a grain size (see 6th ) in a microstructure of the reference component area 60 can lead, whereas a comparatively larger energy input can lead to larger reference false color values 64 as well as larger grain sizes (see 7th ) in the microstructure of the reference component area 60 can lead. Overall, it has been shown that the higher the energy input based on the energy beam 28 in partial areas of the reference component area 60 or the component area 12 A greater structural anisotropy and thus larger material grains also occur in these subregions, the subregions with higher energy input also due to correspondingly higher reference false color values determined by optical tomography 64 or false color values 74 , for example in the form of higher gray values, recognized, in particular quantified. The higher the reference false color values 64 or false color values 74 that is, the greater are the corresponding material grains or the corresponding microstructure anisotropy due to the energy input.

The present layer construction method or the present layer construction device 10 enables an effective estimation of an expected defect distribution in the form of defect frequency and defect size or defect density and additionally or alternatively the number of defects depending on the component geometry based on the determined reference false color values 64 or false color values 74 , which can be, for example, respective gray values. Optical tomography can use the reference false color values 64 or false color values 74 a respective evaluation of an orientation and distribution of material grains of medium and maximum size take place. Optical tomography can also be used to melt the energy beam 28 Influenced heat balance in the component 14th or in the component area 12 be optimized. Optical tomography allows it on the basis of the reference false color values 64 or false color values 74 to recognize the respective sub-areas in which different temperatures prevail. Using optical tomography, for example, heat conduction conditions in the component area 12 or in the reference component area 60 due to the respective component geometry and thus undesired changes of influencing variables such as a scan vector length and a track overlap are avoided. As a result, undesired, substantial changes in the respective reference microstructure or microstructure and associated changes in the material properties (static and cyclic strength, defect density) of the melted material can be avoided 22nd be avoided.

The layer construction method or the layer construction device 10 allow the local intensity maxima 66 to use to adjust the heat balance in a targeted manner. In addition, a reference false color mean value can also be obtained from the reference false color values 64 are formed around the additive manufacturing of the component area 12 or the component 14th based on the reference false color mean value, which can be designed as a gray value position mean value, for example, to be kept stable in layers.

Using the present layer construction method or using the layer construction device 10 can be a correlation between the local intensity maxima 66 the reference false color values 64 and the material properties of the material 22nd as well as the defect distribution can be used around the component area 12 or the component 14th additive manufacturing.

By analyzing each, using the camera 36 recorded layer data of the reference component area 60 or the reference component 62 in relation to the local intensity maxima 66 the changes in the heat balance, as based on 2 recognizable, shown and evaluated.

The reference part area 60 or the reference component 62 can initially with a constant reference exposure parameter value of the energy beam 28 built up and recorded by optical tomography, whereby the reference false color values 64 can be recorded in layers, for example as reference gray values. A normalization and adjustment of the recorded reference false color values 64 on a defined reference target value (with a defined reference microstructure and defect distribution) can be an input variable for the calculation of the component geometry of the component area 12 or the component 14th related parameter in the form of the at least one exposure parameter value, the aim of which is a more uniform microstructure and defect distribution in the component area 12 or in the component 14th supplies.

Show, for example, the reference false color values 64 in the additive manufacturing of the reference component area 60 or the reference component 62 Intensity fluctuations of 20%, the at least one exposure parameter value can be used for additive production of the component area 12 or the component 14th be set in such a way that the energy input during the production of the component area 12 or the component 14th compared to additive manufacturing of the reference component area 60 or the reference component 62 is reduced by 20%.

The analysis of the local reference false color values 64 (for example the local reference gray values) enables a local and therefore location-dependent evaluation of the heat balance and the resulting material properties in the reference component 62 or the component 14th . The analysis of the local reference false color values 64 can be used as an input variable for the component geometry-dependent adaptation of the exposure parameter value. By three-dimensional analysis of one of the individual layers of the reference component area 60 or the reference component 62 Especially relevant areas for a destructive test can be identified when the reference image stack is built up. The possibility of monitoring the reference false color values 64 can also be used to secure parameters for specific structure adjustments with certain mechanical properties.

List of reference symbols

10

Layer building device

12

Component area

14th

Component

16

Powder feed

18th

Powder container

20th

Coater

22nd

material

24

Build platform

26th

Radiation source

28

Energy beam

30th

Control device

32

Facility

34

Heating device

36

camera

40

Scan line

50

Reference monitoring data set

60

Reference part area

62

Reference component

64

Reference false color values

66

local intensity maximum

70

Monitoring record

74

False color values

76

malfunction

II

Build-up and joining zone

III

arrow

B.

Movement of the build platform

Claims (12)

Layered construction method for the additive production of at least one component region (12) of a component (14), in particular a component (14) of a turbo machine, comprising at least the following steps: a) Providing at least one reference monitoring data set (50) which is based on reference false color values (64) recorded by optical tomography of at least one reference component area (60) of a reference component (62) during its additive production and local intensity maxima (66) characterizes the reference false color values (64); b) applying at least one powder layer of a material (22) to at least one building and joining zone (II) of at least one movable construction platform (24); c) local solidification of the material (22) to form a component layer by the material (22) being selectively scanned and melted with at least one energy beam (28) along scan lines (40), at least one exposure parameter value of the energy beam (28) as a function from the at least one reference monitoring data set (50) and thereby depending on at least one of the local intensity maxima (66); d) lowering the construction platform (24) layer by layer by a predefined layer thickness; and e) repeating steps b) to d) until the component area (12) is completed. Layer construction process according to Claim 1 characterized in that the at least one reference monitoring data set (50) characterizes a reference structure distribution at least in the reference component area (60) and at least one reference exposure parameter value assigned to the reference structure distribution. Layer construction process according to Claim 2 , characterized in that as a function of the reference structure distribution and the at least one reference exposure parameter value, at least one correction value is determined by which the at least one exposure parameter value is set differently from the at least one reference exposure parameter value, whereby at least the component area (12) with a structure distribution is provided which has a lower defect density and / or a lower number of defects than the reference structure distribution. Layer construction method according to one of the preceding claims, characterized in that an energy input of the at least one energy beam (28) is set as the at least one exposure parameter value. Layer construction method according to one of the preceding claims, characterized in that in step c) a monitoring data set (70) based on optical tomography of at least the component layer is created, which is used to monitor the additive manufacturing of at least the component area (12) with the reference monitoring data set (50). is compared. Layer construction method according to one of the preceding claims, characterized in that in step c) a laser beam is used as the energy beam (28). Layer construction method according to one of the preceding claims, characterized in that at least one material from the group of steel, aluminum alloys, titanium alloys, cobalt-based alloys, chromium-based alloys, nickel-based alloys, copper alloys, intermetallic alloys or any mixture thereof is used as the material (22). Layer construction device (10) for the additive production of at least one component area (12) of a component (14) by an additive layer construction method, comprising: - at least one powder feed (16) for applying at least one powder layer of a material (22) to at least one construction and joining zone (II) at least one movable building platform (24); - At least one radiation source (26) for generating at least one energy beam (28) for layer-by-layer and local solidification of the material (22) by selective scanning and melting of the material (22) along scan lines (40); and - a control device (30) which is designed to: - control the powder feed (16) in such a way that it applies at least one powder layer of the material (22) to the build-up and joining zone (II) of the building platform (24); and - to control the building platform (24) in such a way that it is lowered in layers by a predefined layer thickness, characterized in that the control device (30) is set up to control the radiation source (26) and thereby at least one exposure parameter value of the energy beam (28) depending on at least one reference monitoring data set (50), wherein the at least one reference monitoring data set (50) is based on reference false color values detected by optical tomography of at least one reference component area (60) of a reference component (62) during its additive manufacture (64) and characterizes local intensity maxima (66) of the reference false color values (64), the control device (30) being set up to set the at least one exposure parameter value of the energy beam (28) as a function of at least one of the local intensity maxima (66) . Layer building device (10) according to Claim 8 , characterized in that it is designed as a selective laser sintering and / or melting device. Computer program product, comprising instructions which, when the computer program product is executed by a control device (30), of a layer construction device (10) Claim 8 or 9 cause the layer building device (10), the layer building method according to one of the Claims 1 to 7th execute. Computer-readable storage medium, comprising instructions which, when executed by a control device (30), follow a layered construction device (10) Claim 8 or 9 cause the layer building device (10), the layer building method according to one of the Claims 1 to 7th execute. Component (14), in particular a turbine component of a turbomachine, comprising at least one component area (12), which by means of a layer construction device (10) Claim 8 or 9 and / or by means of a layer construction method according to one of the Claims 1 to 7th is made.

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