DE102015214994A1 - A method of manufacturing or repairing a component and apparatus for manufacturing and repairing a component - Google Patents

Abstract

The invention relates to a device and a method for producing or repairing a component (32), in particular a blade for gas turbines, wherein at least a part of the component (32) based on a three-dimensional data model of a plurality of layers in a space (6) with the following Steps is formed. In step a) the installation space installation space (6) is provided. In step b), a metal powder is applied to at least one predetermined area of the construction space (6). In step c), the predetermined area for locally fusing the powder (41, 42) to produce the part of the component (32) is irradiated. In this case, at least one entire layer (60, 62) of the component (32) is produced in step c). After step c), a step d) follows. In step d), at least a portion (52) of this layer (60, 62) is reheated to a temperature which is lower than the melting temperature of the metal powder.

Description

The invention relates to a method for producing or repairing a component according to the preamble of claim 1. The invention further relates to a device for producing and repairing a component according to the preamble of claim 12.

STATE OF THE ART

The prior art discloses generative manufacturing processes for the rapid production of prototypes or for the production of components which are difficult to produce by other processes. Inter alia, methods such as selective laser melting (SLM), direct metal laser sintering (DMLS) or electron beam techniques are used. From the prior art, in particular also generative manufacturing processes for the production of components of a turbomachine, such as components of an aircraft engine or a gas turbine are known, for example, in the DE 10 2009 051 479 A1 described method or a corresponding device for producing a component of a turbomachine.

In this method, a corresponding component is produced by layer-wise application of at least one powdered component material on a component platform in the region of a buildup and joining zone as well as layer-by-layer and local melting or sintering of the component material by means of energy supplied in the region of the assembly and joining zone. The energy is supplied by laser beams, such as CO2 lasers, Nd: YAG lasers, Yb fiber lasers and diode lasers, or by electron beams. In the in the DE 10 2009 051 479 A1 described method, the produced component or the assembly and joining zone is further heated to a temperature just below the melting point of the component material by means of a zone furnace to maintain a directionally solidified or monocrystalline crystal structure.

From the publication DE 10 2006 058 949 A1 Also, an apparatus and method is known for rapidly producing and repairing blade tips of blades of a gas turbine, particularly an aircraft engine, using inductive heating in conjunction with laser or electron beam sintering.

To reduce the thermal gradient in combination with crack formation, a general heating of a (powder) layer can be provided. There are two variants of such additional heating or additive manufacturing processes.

One variant is that the heating in the layer-by-layer generative structure takes place via a heating plate (electrically). This is such that by means of a hotplate, the (metallic) component including the starting material (powder) to be built up is heated, in such a way that over this component (by thermal conduction) the temperature at which the next layer is to be built up brought to melt the powder is required.

The second variant is such that the working space in which the generative manufacturing process is carried out is itself a furnace. In other words, the component is generatively constructed in an oven. The furnace generates a uniform (high) temperature, which is necessary to build up the appropriate layer, and inevitably heats the entire component to be built up or built up.

In the publication DE 10 2012 206 122 A1 An apparatus and method for the generative production of a component is described. For local heating, two induction coils arranged above one another are used here, which accordingly pre-heat and / or reheat a joining zone located in the crossing region of the coils. The heat treatment thus takes place during the construction of the layer. The induction coils must follow the laser. This has the disadvantage that due to the inertia of the coils only limited melting can be driven. Thus, for structural mechanical reasons, it may be necessary for the laser beam to produce one part of the layer on one side of the construction space and for it to jump on another side of the installation space in the next moment, in order then to produce a further part of the layer there. This is only possible in that the process is slowed down so that the coils can be positioned accordingly. However, this has the disadvantage that then the generative process is unprofitable.

Thus, the object of the present invention is to provide a method which overcomes the disadvantages listed above.

The object is achieved by a method having the features of claim 1. The object is further achieved by a component having the features of claim 11. The object is further achieved by a device having the features of claim 12.

The invention relates to a method for producing or repairing a component. It will formed a part of the component based on a three-dimensional data model of a plurality of layers in a space with the following steps. In step a) the installation space is provided. In step b), a metal powder is applied to at least one predetermined area of the installation space. In step c), the predetermined region is irradiated, so that the powder melts locally and thereby a part of the component is produced. In step c), furthermore, at least one entire layer of the component is produced. After this step c), a step d) follows. In this step d) at least a portion of this layer is post-heated to a temperature which is lower than the melting temperature of the metal powder.

It is noted that the subregion is smaller than the newly generated device layer. This can be specifically reheated locally. It is important that the corresponding layer has been completely produced before the postheating is carried out. Not every layer needs to be heated up. Preferably, the reheating can be done, for example, only every 2 to 10 layers. Suitable metal powders are, for example, nickel superalloys, MAR 247 or René 108.

In an advantageous embodiment of the invention, steps b) and c) take place simultaneously or successively. The three-dimensional data model is divided into several parallel layers. The energy beam strikes a powder bed in selective overlay welding (SLM). At the point where the energy beam strikes the surface of the powder bed, the powder melts. In this case, only the areas of the powder bed are exposed to the energy beam, which emerge from the three-dimensional data model for the layer to be created at the moment. After exposure, the component is lowered by one piece. In this case, the powder bed receives a fresh powder layer, so that the steps b) and c) are carried out one behind the other.

In laser powder build-up welding, by contrast, powder is conveyed directly into the energy jet by means of a powder nozzle, so that steps b) and c) take place simultaneously in this process.

In a further advantageous embodiment of the invention, the steps b) to d) are repeated until all layers of the part of the component are produced.

In a further advantageous embodiment of the invention, the irradiation in step c) by means of a laser beam and / or an electron beam. An electron beam has the advantage that it can be divided into several virtual beams (up to 200). The deflection of an electron beam, for example, by means of magnetic coils and / or capacitor plates, so that this beam can be deflected faster than an optical beam.

In a further advantageous embodiment of the invention, before step b) or step c), a locally limited, direct or indirect preheating of the installation space to a temperature which is greater than a predetermined minimum temperature and less than the melting temperature of the metal powder. This significantly reduces the energy input of the energy beam. The preheating can be done for example by means of a furnace, an energy beam and / or inductively.

In a further advantageous embodiment of the invention, the reheating takes place in step d) by at least one induction coil. Preferably, the local reheating by means of two crossed coils. This means that the component can be reheated very selectively and in a very small area. Furthermore, this has the advantage that the actual welding process is completely decoupled from the subsequent reheating. The inductive reheating until just below the melting point of the powder material causes defects, such as cracks, to heal. The temperature may be between 1000 ° C and 1300 ° C.

In a further advantageous embodiment of the invention, the installation space is optically and / or thermally detected during step c) or during step d) in order to detect the position of at least one defect, in particular a crack. An optical / thermal detection device for detecting defects is, for example, in the document DE 10 2013 201 629 A1 disclosed. Preferably, based on this information in step d), the position of the defect is reheated. Preferably, only the position of the defect or the positions of the defects is reheated to specifically heal these defects. This saves a lot of time.

In a further advantageous embodiment of the invention, in step d) after a certain pattern reheating. This serves to test the annealing or else step d) is simply repeated. Thus, for example, the outer contour of the last layer of a hollow blade can be moved clockwise. In conjunction with the cheeses, it is possible to specifically cure the outer walls of a component. In particular, if the material is to be applied monocrystalline, for example, orientation errors or lattice defects can be remedied.

The invention further relates to a device for producing and repairing a component. In this case, at least a part of the component is based on a formed three-dimensional data model of a plurality of layers in a space. The device comprises the installation space, an energy source for generating an energy beam, which is directed towards the installation space, an application unit of metal powder and a local heat source. In this case, the heat source is operated such that after generation of at least one entire layer of the part of the component, a partial region of this layer has a temperature which is lower than the melting temperature of the metal powder.

Further advantageous embodiments of the invention are given in the dependent claims.

Furthermore, preferred embodiments of the invention will be described in more detail with reference to the schematic drawing. Showing:

1 : a page presentation of a SLM system, and

2 : A top view on three area of the SLM facility 1 ,

The 1 shows a page display of a SLM system 2 with three areas 4 . 6 and 8th , a protective bell 10 which is a chamber 12 encloses, an energy source 14 connected to a control unit 16 is connected, and with a detection unit 18 , The three areas 4 to 8th are through four vertical walls 20 . 22 . 24 and 26 separated from each other.

The first area 4 is located here at the bottom left has a vertically movable residual powder table 28 on, between the first wall 20 and the second wall 22 is arranged. The residual powder table 28 is preferably moved vertically down to the receiving volume for the remaining powder 29 to enlarge if necessary.

The second area 6 is to the right of the first area 4 arranged. The second area 6 includes between the second wall 22 and the third wall 24 a construction table 30 on which a component 32 located. The component 32 is in the powder bed 34 embedded. If necessary, the construction table 30 moved vertically downwards. The second area 6 represents the installation space. The component 32 has a lower area 32a and an upper area 32 b on. In this case, the lower area 32a be an existing shovel in this facility 2 is repaired. So, the upper area represents 32b the area to be repaired. In another case, the lower area 32a one in the plant 2 Represent constructed sub-blade. The upper area 32b then represents the area still to be produced.

The third area 8th is right of the second area 6 arranged. The third area 8th includes between the third wall 24 and the fourth wall 26 another table 36 for the powder supply 38 , The further table 36 can be moved vertically upwards if necessary. Over the fourth wall 26 is a squeegee 40 arranged the metal powder from the powder supply 38 takes over the space 6 distributed and the remaining powder 29 in the second area 4 pushes. Thus, the squeegee 40 because there is a uniform fresh powder layer 41 respectively. 42 in the installation space 6 is applied.

Over the three areas 4 to 8th are a first in the y direction running rail 44 with a first induction coil 46 and a second x-directional rail 48 with a second induction coil 50 arranged. The spools 46 and 50 Here are essentially rectangular with rounded corners. Other coil forms can be found in the publication DE 10 2014 204123 be removed. The spools 46 and 50 are here in 1 arranged in parking position.

The 2 shows a plan view of the three areas 4 to 8th , In the installation space 6 is the upper area 32b of the component 32 visible, noticeable. The first coil 46 is located here in y-direction at the bottom. The second coil 50 is arranged in the x-direction such that the two coils 46 and 50 at the front edge 52 of the component 32 , here a turbine shovel, overlap. This allows locally the leading edge 52 warmed up (heated up), as explained below.

Now, an embodiment of the method according to the invention with reference to the two 1 and 2 explained.

First, the squeegee carries 40 in step b) a first fresh powder layer 41 on. Subsequently, in step c) the energy source 14 (here a laser) so controlled that the energy beam 15 the fresh powder layer 41 in the powder bed 34 meets and a first component layer 60 manufactures. For example, steps b) and c) are repeated again here. The squeegee 40 carries a second fresh layer of powder 42 on. Subsequently, in step c) the energy source 14 so controlled that the energy beam 15 on the second powder layer 42 at the point 62 impinges and there brings the powder to melt. In 1 is only a first part of the second component layer 62 displayed. During the exposure of the component room 6 can the registration unit 18 absorb the radiation energy. As a registration unit 18 For example, a CCD camera can be used. Such CCD cameras can still detect the near infrared range. Should be in the first 60 and second 62 Component layers Defects such as cracks may be included, so the evaluation unit 14 , the xy position of the defects from the information of the CCD camera 18 determine. It should be noted that the exposure parameters in step c) are selected such that the microstructure of the individual component layers 60 and 62 if possible no or small cracks are generated.

After here the first two component layers 60 and 62 have been made, these layers by means of the two coils 46 and 50 reheated in step d). Here are the two coils 46 and 50 positioned accordingly so that the crossing area 64 the coils over the freshly prepared layers 60 and 62 is arranged. The two coils 46 and 50 are then operated with alternating current. This results in the crossing area 64 Such a high alternating magnetic field that only in the component layers 60 and 62 By induction, an alternating current flows that the component 32 heats up at the appropriate place. The temperature remains below the melting point of the component material. Because of the high electrical resistance of the powder bed 34 No alternating currents can flow therein, so that the powder remains relatively cool. The two coils 46 and 50 can be controlled such that the crossing area 64 always over the outer contour of the component 32 (For example, a blade wall) is arranged. The crossing area 64 can be moved, for example, clockwise until this is the contour of the component 32 at least once.

Alternatively or in combination, the crossing area 64 to the from the drive unit 14 determined defect sites are positioned to heal specifically identified defects.

The temperature in the crossing region can be determined, for example, by means of the detection unit 18 be measured. By means of the evaluation unit 16 can the temperature in the crossing area 64 be regulated again.

With this method and device according to the invention, the melting step can be completely decoupled from the postheating step. The reheating temperature is between 20 ° and 100 ° C below the melting temperature of the powder.

LIST OF REFERENCE NUMBERS

2

SLM system

4

first area

6

second area

8th

third area

10

protective bell

12

chamber

14

Energy source (laser)

15

energy beam

16

control unit

18

acquisition unit

20

first wall

22

second wall

24

third wall

26

fourth wall

28

Residual powder table

29

remaining powders

30

build table

32

component

32a

lower area of 32

32b

upper area of 32

34

powder bed

36

another table

38

powder storage

40

doctor

41

first fresh powder layer

42

second fresh powder layer

44

first rail

46

first coil

48

second rail

50

second coil

52

Leading edge of 32

60

first component layer

62

second component layer

64

Crossing area of 46 and 50

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009051479 A1 [0002, 0003]
• DE 102006058949 A1 [0004]
• DE 102012206122 A1 [0008]
• DE 102013201629 A1 [0019]
• DE 102014204123 [0030]

Claims (14)

Method for producing or repairing a component ( 32 ), in particular a blade for gas turbines, wherein at least a part of the component ( 32 ) based on a three-dimensional data model of a plurality of layers in a construction space ( 6 ) is formed with the following steps: a) providing the installation space ( 6 ); b) applying a metal powder to at least one predetermined area of the construction space ( 6 ); c) irradiating the predetermined area for locally fusing the powder ( 41 . 42 ) for producing the part of the component ( 32 ); characterized in that in step c) at least one whole layer ( 60 . 62 ) of the component ( 32 ) and after step c) a step d) follows, wherein in step d) at least a portion ( 52 ) of this layer ( 60 . 62 ) is reheated to a temperature which is less than the melting temperature of the metal powder.  The method of claim 1, wherein steps b) and c) occur simultaneously or in succession. Method according to at least one of the preceding claims, characterized in that the steps b) to d) are repeated until all layers of the part of the component ( 32 ) are made. Method according to at least one of the preceding claims, characterized in that the irradiation in step c) by means of a laser beam ( 15 ) and / or an electron beam. Method according to at least one of the preceding claims, characterized in that before step b) or step c) a locally limited, direct or indirect preheating of the installation space ( 6 ) to a temperature greater than a predetermined minimum temperature and less than the melting temperature of the metal powder. Method according to at least one of the preceding claims, characterized in that in step d) the reheating by at least one induction coil ( 46 . 50 ) he follows. Method according to at least one of the preceding claims, characterized in that in step d) the temperature is between 1000 ° C and 1300 ° C. Method according to at least one of the preceding claims, characterized in that during step c) or during step d) the installation space ( 6 ) is optically and / or thermally detected to determine the position of at least one defect ( 66 ), in particular a crack. Method according to claim 8, wherein in step d) the position of the detected defect ( 66 ) is reheated or wherein the step d) is repeated. Method according to at least one of the preceding claims, characterized in that in step d) is reheated according to a specific pattern.  Component, manufactured or repaired according to at least one of the preceding claims. Device for producing and repairing a component ( 32 ), wherein at least a part of the component ( 32 ) based on a three-dimensional data model of a plurality of layers in a construction space ( 6 ), the device comprising: - the installation space ( 6 ), - an energy source ( 14 ) for generating an energy beam ( 15 ), on the space ( 6 ), - an order unit ( 40 ) of metal powder and - at least one local heat source ( 46 . 50 ), characterized in that the heat source ( 46 . 50 ) is operated such that after generation of at least one entire layer of the component ( 32 ) a portion of this layer ( 60 . 62 ) has a temperature which is lower than the melting temperature of the metal powder. Apparatus according to claim 12, wherein the heat source comprises at least one induction coil ( 46 . 50 ) having. Device according to at least one of claims 12 to 13, characterized in that the energy source ( 14 ) has a laser and / or an electron gun.

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