DE102009037893A1 - Production of hollow bodies or layers with cavities - Google Patents

Abstract

The invention relates to a method and components produced thereby, which comprise the steps of producing a hollow body having at least one cavity and / or for forming coatings having cavities on components:
Production of a shaped body (1) having an outer shape at least partially having the shape of the cavity, wherein the shaped body can be displaced by a solvent or by melting into a flowable state,
Coating the shaped body with a layer material (2) which forms the hollow body,
Removing the shaped body from the hollow body by dissolving or melting;
wherein the coating of the shaped body is carried out by powder injection molding and / or several layers are provided with different material composition during coating of the shaped body.

Description

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The The present invention relates to a process for producing a Hollow body and a method for repair and / or Production of cavities in a coating.

STATE OF THE ART

The Shaping of materials to form components becomes diverse used in the prior art. Nevertheless, there is still a Need to improve the efficiency of the process and components with optimized properties.

From the DE 40 23 618 C1 the production of a hollow shaped body made of metal, hard metal or ceramic is known in which a core is surrounded by a salt by flame or plasma spraying with a material. After the construction of the sheath, the core is dissolved by water and dissolved out of the hollow body. As a result, a molded hollow body or molded body having a complex cavity geometry can be produced. However, the applicability of the process due to the salt core and the coating method used is severely limited.

From the DE 10 225 062 A1 For example, a method of forming cooling passages for cylinder liners in an internal combustion engine is known in which the cylinder liners are produced by coating. Here, in the surface to be coated, a wire of AlSn20 is inserted into corresponding grooves of the engine block to be dissolved by water after coating, so that cooling channels are formed under the coating.

Although there are known methods which allow to form components having cavities and hollow bodies, wherein a mandrel is coated and the coated core is dissolved after the application of the coating to form the cavity, their use is less widespread. This may be because of the fact that DE 40 236 18 C1 a core of a salt is used, which is difficult to handle and can be coated only to a limited extent. In the DE 10 225 062 A1 the method is limited to provide only a flat coating and insert the metal to be dissolved as a preformed wire in a groove. Thus, the application is limited accordingly.

DISCLOSURE OF THE INVENTION

OBJECT OF THE INVENTION

It is therefore an object of the present invention, a method and to provide appropriate components that the Overcome the disadvantages of the prior art and a general and flexible, usable for three-dimensional structures Production possibility for arbitrarily shaped To create hollow body. In particular, a method be given, which is a simple, easy to handle way creates, arbitrarily complex three-dimensional hollow body structures to create or restore a sufficient mechanical Have stability and their surface in the cavity may have defined properties.

TECHNICAL SOLUTION

These The object is achieved by a method for the production corresponding hollow body with the features of the claim 1 and / or claim 3 and a method for repair and / or Production of cavities in a coating on a Component with the features of claim 4 and by components according to the Features of claim 17. Further advantageous embodiments are the subject of the dependent claims.

To A first aspect of the present invention is a method for producing a hollow body of metal, ceramic, Glass, quartz, plastic or similar composites claimed for example of metal and ceramic, in which the Hollow body has at least one cavity and which the production of a shaped body with an at least partially provides the shape of the cavity having outer shape. The molded body is formed of a material which by a solvent such as water or Acid, or by melting in a flowable Condition is displaceable, so that the molding after the Production of the hollow body or cavity out of this can be solved. This is the material for the shaped body chosen so that the melting temperature is in an area which, for the hollow body formed is harmless.

Of the corresponding shaped body is covered with a layer material coated, which forms the hollow body. After the education of the hollow body through the coating of the molding the molding is dissolved in accordance with a solvent or melted and from the hollow body or the corresponding Cavity out solved.

The Coating of the shaped body takes place according to the invention the first aspect of the invention by powder injection molding. These methods have over that of the prior Technique known procedure has the advantage of being defined, even thick and in particular stable, usable as structural components Hollow body can be formed. The powder injection molding also allows the use of materials that otherwise to form a corresponding hollow body under circumstances could not be used. In addition, you can very complex cavity geometries are made possible.

To another aspect of the present invention, for independently and independently as well as in combination With other aspects of the invention, protection is sought Method of producing a hollow body of metal, Ceramic, plastic, glass, quartz or a composite material, for example made of metal and ceramic by coating a shaped body thereby extended over the prior art and the Area of use thus made more flexible by the coating of the Shaped body to form the hollow body deposition comprises several layers. This allows functional and Protective layers disposed on the surface of the cavity so that components for a wide variety of uses can be made. In addition, again uniform layer thicknesses for very complex cavity geometries be achieved.

To another aspect of the present invention, for independently and independently as well as in combination With other aspects of the invention, protection is sought Process, in particular for the production and / or repair of coatings be provided by a component, wherein the coating at least includes a cavity that passes through the coating. Such a component may for example be a turbine component, such as a turbine blade, the cooling channels which pass through the coating. By the inventive method with the training a shaped body, arranging the shaped body the component and coating the shaped body and the component with the layer material which forms the coating and which The corresponding cavities can be very simple In turn, a complex cavity geometry in both the new production corresponding components as well as in the repair of the component formed become. Especially for the repair of turbine blades with thermal barrier coatings and corresponding corrosion and diffusion protection layers, which are also cooling channels have a corresponding method as a repair method proved to be advantageous.

For this For example, the molded body whose outer shape the extension of a recess in the component, such as a cooling duct, simply on the component, in particular be partially arranged in the recess, so that subsequently the coating of the component replenished or reapplied can be.

Also here two or more layers can be deposited, so that in particular a multilayer layer construction, as often with corresponding turbine blades with thermal barrier coatings and hot gas corrosion protection layers can be found built can be.

at the formation of protective layers and / or functional layers the surface of the cavity to be formed, the corresponding protective and / or functional layers are first applied to the molding and subsequently only the layer material is applied, which the actual hollow body or the coating of a component forms.

With Protective layers are both protective layers meant as protection serve subsequent layers in the manufacturing process, as well Protective layers, the hollow body or the cavity in the Protect later use, even if this is here can also be referred to as functional layers.

Corresponding the protective layers can in particular waterproof lacquer layers and metallic layers of nickel, nickel-chromium alloys, MCrAlY alloys with M = nickel and / or cobalt include, where For example, the waterproof lacquer layers serve the following Layers before an attack of the solvent water Dissolve the molded body with water to protect. Correspondingly, acid-resistant layers can also be used be provided when acid as a solvent is used. Generally solvents can thus stable layers that are used on the Solvent for dissolving out the molding are coordinated.

The metallic layers of nickel, nickel-chromium alloys and / or MCrAlY alloys with M = nickel and / or cobalt are used in particular the protection in further depositions of layers, for example by high-speed flame spraying or kinetic cold gas spraying.

As functional layers, a multiplicity of very different layers can be provided, which can fulfill a wide variety of functions on the surface or in the near-surface region of the surface of the cavity. For example, Kings A slurry layers are deposited, which serve to produce a diffusion coating, in particular a Alitierung or an inching. There may be provided metallic donor layers for diffusion coatings, in particular chromium, aluminum, platinum and / or palladium layers, which may contribute to the corresponding processing of the hollow body or the coating on a component to corresponding diffusion coatings, the z. B. again provide corrosion resistance for the cavity. In addition, metallic layers for the production of conductivity, hard coatings against wear, thermal barrier coatings, such as zirconium-stabilized yttria for temperature protection, corrosion protection layers such as MCrAlY layers with M = nickel or cobalt or ceramic layers can be provided. In principle, the provision of various functional layers with all possible suitable functions is possible.

at the deposition of multiple layers on the molding and / or in the repair and / or production of coatings with continuous Cavities can be a variety of coating methods such as electroplating, thermal spraying, Arc wire spraying, high-speed flame spraying, plasma spraying, Powder injection molding, metal powder injection molding, Ceramic powder injection molding, cold gas spraying, kinetic Cold gas spraying, build-up welding, laser powder build-up welding, Slip application, brushing, brushing, spray spraying, chemical and electroless metallization and combinations thereof. Especially can different layers in a layer stack, be applied with different coating methods.

at the use of the powder injection molding in particular the Metal powder injection molding or ceramic powder injection molding The manufacturing process also includes a step of removing the Binder (debindering) and / or a sintering step and / or heat treatment of the layer material of Injection molded green body. The molded body can be either from the injection-molded green body, the binder removed brown part (metal powder injection molding) or White part (ceramic powder injection molding) or finished sintered hollow body are dissolved out.

The Binder, which is used for shaping in powder injection molding is provided, can be chosen so that a dissolution of the molded article without attacking the binder the greenling takes place. In this case can then on a corresponding protective layer between the molding and the Layer material for the formation of the hollow body or the coating can be dispensed with.

at the preparation of the hollow body or the coating can Further process steps, such as the processing of the outer Shape of the deposited layers or individual layers and / or steps for adjusting the properties of the material or materials, for example by temperature treatment, be provided. In particular, a temperature or heat treatment to be provided, which is the final Generation of the surface layer (s) on the surface of the cavity.

By the inventive method can complicated cavity geometries are provided with coatings and be provided on corresponding components. In particular are complex cavity geometries possible, with a coating of the molding of more than one side, in particular a circumferential coating can be made from several sides. at Contemplation of a body of six pages according to the independent one Spatial directions, for example in a Cartesian coordinate system, In particular, a coating of four or five Pages take place, each with two sides of an independent Spaced spatial direction.

Corresponding become according to a further aspect of the present invention also for the components produced by the process protection particularly for air turbine components, such as air turbine blades, as well as in particular hollow bodies with complex cavities which are almost completed or difficult to access and still a uniform, homogeneous coating have the surface of the cavity.

BRIEF DESCRIPTION OF THE FIGURES

The Further advantages, characteristics and features of the present invention will be in the following detailed description of embodiments be clear from the attached drawings.

The Figures show this in a purely schematic way in

1 the method steps for producing a hollow body according to a first embodiment of the invention;

2 the process steps for repair or production of a coating with cavities according to a second embodiment of the invention;

3 the process steps for the production a hollow body with provided on the surface of the cavity coating according to a third embodiment of the invention, and in

4 the process steps for the production of a hollow body with provided on the surface of the cavity coating according to a fourth embodiment of the invention.

EMBODIMENTS

The 1 shows in the sub-images a) to d) process steps for producing a hollow body 5 according to a first embodiment of the invention. In this case, according to the partial image a) first a shaped body 1 made, which can also be referred to as a blank. This shaped body can be formed, for example, from a water-soluble alloy such as AlSn20. For this purpose, all manufacturing and molding processes that are suitable for the production of the molded article, conceivable.

The molded body 1 is then covered with a coating 2 provided according to a first embodiment of the invention by powder injection molding process. Will the coating 2 made of a metallic material, the metal powder injection molding method is used, while in a ceramic coating or a coating of a composite material of metal and ceramic, such as cermet, a ceramic powder injection molding method is used. In these methods, the metal or ceramic powder or powder made of a composite material is provided with a binder and injected via an injection molding process in a mold, in which the molding 1 is included as a core.

After injection molding of the powder with binders, a so-called green body is present, which contains the powder with the binder as a coating on the shaped body 1 includes (see drawing c)). The greenling 3 can now be further processed into a finished hollow body, in which the binder is dissolved out. The binder can be dissolved out by dissolving in a solvent, by melting or by catalytic debinding, ie the transfer of the binder in the gaseous state. The resulting brown part in metallic materials or white part in ceramic materials can be brought by a corresponding heat treatment, ie sintering in the finished form or the final state. In the heat treatment of the finished sintered component, the heat treatment can be carried out so that a correspondingly suitable adjustment of the properties of the coating material or of the material of the hollow body is set.

After the finished sintering of the hollow body 5 can the molding 1 by melting or dissolving, for example, be dissolved out in water, so that the cavity 4 in the finished manufactured component or hollow body 5 results.

However, according to an alternative approach, the shaped body 1 already from the green 3 or be dissolved out after the leaching of the binder from the brown part or white part. Will the molding 1 is leached from the green compact by a solvent such as water or an acid, the binder for the injection-molded powder should be chosen so that it is not affected by the solvent for the molding 1 is dissolved out. Alternatively, as shown in another embodiment, the first layer may be a protective coating on the molding 1 be provided, which protects the subsequent layer, which forms the later hollow body, during the dissolution of the molded body from the solvent.

The 2 shows in the sub-images a) to e) another embodiment of the invention, in which cavities are produced in a coating or a corresponding coating, which should have cavities, can be repaired. In particular, the shows 2 a method for producing a coating or repair of a coating of a turbine component, such as a turbine blade, the cavities, such as cooling channels comprises.

In the embodiment of the 2 becomes according to the partial image a) first a component 10 which cavities 11 has provided. For example, this may be a turbine blade 10 with cooling channels 11 act.

As in drawing b) the 2 can be seen, are in the cooling channels 11 at least partially shaped body 12 used, which in turn can be made in any suitable manner from a material which is suitable as a core for the formation of the coating and can be subsequently dissolved or melted accordingly. The molded body 12 This represents an extension of the cooling channels 11 represents.

On the prepared component 10 becomes a coating in a suitable manner 13 applied, which the one or more moldings 12 from several sides at least partially encloses. Are the moldings 12 For example, formed as pins in the cooling channels 11 the component of the turbine blade 10 are arranged according to the coating, as shown in drawing c) 2 is enclosed by five pages, which are assigned to the independent spatial directions.

The layer 13 is in accordance with part d) the 2 mechanically reworked, with part of the layer 13 is removed and also a part of the moldings 12 Will get removed. This results in a machined surface 14 the layer 13 , In this finished state, the moldings 12 from the cooling channels 11 dissolved, for example, by dissolving in water or other solvent such as acid or melting out, so that the cavities 16 as an extension of the cooling channels 11 in the layer 13 be formed. This can be easily for turbine blades 10 with cooling channels 11 coatings 13 Achieve a passage of the cooling channels 11 exhibit.

The 3 shows in the diagrams a) to h) a further embodiment of the invention, in which a component having a cavity, that is a hollow body 27 is created, which in the interior or cavity 26 a diffusion coating, for example an alitier layer or an inching layer (alitization or inchomation) 28 has (see sub-picture h) of the 3 ). In this embodiment, in turn, a shaped body 20 made of, for example, a water-soluble alloy or other fusible or dissolvable material which can be suitably shaped into the appropriate shape.

On this molding 20 is a paint job of a waterproof paint 21 applied to protect the subsequently applied coating when dissolving out the molding 20 serves.

At the protective layer 21 it can also be a metallic protective layer in addition to the water-resistant paint. Alternatively, a donor layer for the diffusion coating could also be provided here, for example a chromium layer in the case of a chromium plating.

On the paint layer 21 becomes a slip 22 applied, which is used for the subsequent diffusion coating. For example, this may be a slip of the brand name Ceral 10 for the Alitierung or Ceral 20 act for the chroma. The slip layer can be applied by brushing or by application by means of a spray gun, ie by spray spraying.

On the slip layer 22 for the subsequent diffusion coating can be another protective or functional layer 23 such as a water insoluble lacquer to protect the slurry, a seed layer with, for example, palladium to render the device conductive, a nickel layer applied by electroplating or electroless nickel plating, a platinum or palladium plated layer to form a Platinum / aluminum layer or a palladium / aluminum layer, if the slip layer is intended for Alitierung, as well as a metallic layer such as a layer of nickel, nickel-chromium or MCrAlY with M = Ni and / or Co. These layers can in different manner by thermal spraying, chemical, electroless plating, electrodeposition or be applied in any other suitable manner. Here are a variety of functional and / or protective layers in multilayer design and in any combination conceivable.

On this optional functional and / or protective layer 23 , which may also be omitted, if the subsequent coating process for applying the base material for the hollow body allows this, as for example in powder injection molding, the material for the formation of the essential structure of the hollow body, the so-called base material is applied, in which case all coating methods used can be used to form an appropriate layer on the prepared molding 20 possible are. Here are all methods, such as thermal spraying, electrodeposition, Pulverspritzgießverfahren, build-up welding or other methods conceivable. In particular, high speed flame spraying, plasma spraying such as arc wire spraying or cold gas kinetic spraying, as well as metal powder injection molding and ceramic powder injection molding can be used. The base material layer 24 can according to the drawing f) the 3 If necessary, mechanically processed, such as with the machined surface 25 in part f) of the 3 is indicated. This step can be omitted, for example, in the powder injection molding process.

After completion of the shape of the hollow body material 24 or the base material layer 24 can the molding 20 be dissolved out by suitable methods such as dissolution or melting from the hollow body, so that a cavity 26 gives as in part g) the 3 you can see.

Thereafter, a temperature treatment of the hollow body closes 27 at which partially the applied layers 21 . 22 . 23 dissolve and / or at least appropriately convert or with each other or with the base material of the hollow body, in the layer 24 has been separated, react. As a result, for example, forms a diffusion layer 28 made out as alitating or inchomizing the surface of the cavity 26 even with complex cavity geometry evenly and homogeneously, and in particular with uniform layer thickness surrounds.

The 4 shows a further embodiment of the present invention, wherein the individual process steps schematically in the sub-images a) to e) of 4 are shown.

In the first step, according to part of a) the 4 again a shaped body 30 provided, which is formed of a material which can be shaped accordingly and can be dissolved or melted again. For example, again it may be a water-soluble alloy such as AlSn20. A coating layer, such as an MCrAlY layer with M = Ni and / or Co, is applied to the shaped body, with all possible suitable deposition methods being suitable. In particular, multi-layer systems of metallic, ceramic or corresponding composite materials can be applied.

On the coating 31 in sub-step b) of 4 has been applied, in turn, a layer 32 applied, which comprises the material for the actual hollow body. Also this layer 32 can be applied with all common coating methods, for example, kinetic cold gas spraying may be preferred.

The layer 32 is again brought in the form of step d), wherein, for example, a mechanical, such as tensioning machining of the outer mold is possible.

After the completion of the hollow body 34 in the form of a corresponding formation of the outer layer 32 becomes the shaped body 30 dissolved out, such as by dissolving the shaped body by means of water, so that a cavity 35 is formed. In this way, a hollow body with a cavity 35 are formed, which has an inner pad layer, for example, MCrAlY. Here may be another heat treatment to form suitable properties of the hollow body 34 connect, wherein the heat treatment for forming the support layer is not required, as for example in the diffusion layers of the embodiment of 3 the case was.

Even though the present invention with reference to the accompanying embodiments has been described in detail and in detail is for the expert of course that the Invention is not limited to these embodiments but rather modifications in the form of different combinations the features as well as by omitting individual features possible are without the scope of the appended claims leave.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 4023618 C1 [0003, 0005]
• - DE 10225062 A1 [0004, 0005]

Claims (17)

Method for producing a hollow body having at least one cavity, comprising the steps of: producing a shaped body ( 1 ) having an outer shape at least partially having the shape of the cavity, wherein the shaped body is displaceable by a solvent or by melting in a flowable state, coating the shaped body with a layer material ( 2 ), which forms the hollow body, detaching the shaped body from the hollow body by dissolving or melting; characterized in that the coating of the shaped body is carried out by powder injection molding. Method according to claim 1, characterized in that that during coating of the molding several layers be provided with different material composition. Method for producing a hollow body having at least one cavity, comprising the steps of: producing a shaped body ( 20 ) with an at least partially the shape of the cavity ( 26 ), wherein the shaped body is displaceable by a solvent or by melting in a flowable state, coating the shaped body with a layer material which forms the hollow body, detaching the shaped body from the hollow body by dissolving or melting; characterized in that during coating of the shaped body a plurality of layers ( 21 . 22 . 23 . 24 ) are applied with different material composition. Method for repairing and / or producing a coating with at least one cavity ( 16 ) on a component ( 10 ), wherein the cavity extends through the coating, in particular production and / or repair of coatings with cooling channels on turbine components, in particular turbine blades, comprising the steps: production of a shaped body ( 12 ) having an outer shape at least partially having the shape of the cavity, wherein the shaped body is displaceable by a solvent or by melting in a flowable state, arranging the shaped body on the component, coating the shaped body and the component with a layer material which forms the coating, wherein the shaped body protrudes from the surface of the deposited coating or the coating is subsequently removed again at least to the shaped body, detaching the shaped body from the coating forming a hollow body by dissolving or melting. Method according to claim 4, characterized in that that the shaped body, the extension of a recess represents in the component and the molding partially in the Recess is arranged in the component. Method according to one of claims 4 or 5, characterized in that during the coating of the shaped body at least two or more layers of different material composition be deposited. Method according to one of claims 2, 3 or 6, characterized in that the layers functional layers for adjusting the surface of the cavity and / or protective layers to protect the first deposited layers from further coating steps include. Method according to claim 7, characterized in that that the protective layers at least one waterproof lacquer layer and metallic layers of nickel, nickel-chromium alloys and MCrAlY alloys with M = Ni and / or Co include. Method according to claim 7, characterized in that that the functional layers at least one layer from the group comprising slip layers for producing a diffusion coating, Slip layer for creating an alitization, slip layer to produce a chroma, a metallic donor layer for a diffusion coating, a Cr, Al, Pt and / or Pd donor layer for a diffusion coating, metallic layers for the generation of conductivity, hard coatings, thermal barrier coatings, Corrosion protection layers, wear protection layers, MCrAlY layers with M = Ni or Co, ceramic layers, zirconium stabilized yttria. Method according to one of claims 3 to 9, characterized in that the coating of the shaped body by one or more methods from the group comprising: galvanic coating, thermal spraying, electric arc wire spraying, High-speed flame spraying, plasma spraying, powder injection molding, Metal powder injection molding, ceramic powder injection molding, Cold gas spraying, kinetic cold gas spraying, build-up welding, Laser powder build-up welding, slip application, painting, Spray spraying, chemical, electroless metallization and Combinations of it. Method according to one of claims 1 or 10, characterized in that the method comprises a step of removing the binder (Entbin and / or comprises a step of sintering and / or heat treatment of the layer material of the green body produced by injection molding. Method according to one of claims 1, 10 or 11, characterized in that the shaped body of the injection-molded green body, freed from the binder Brown part or white part or the finished sintered hollow body is solved out. Method according to one of claims 1 or 10 to 12, characterized in that the powder of metal, ceramic or a composite material thereof during injection molding a binder is held in the form, which upon dissolution of the molded body from the hollow body not from the injection molded body Will get removed. Method according to one of the preceding claims, characterized in that the shaped body by water or an acid is dissolved out. Method according to one of the preceding claims, characterized in that the method comprises at least one step the processing of the outer shape of the deposited Layer or individual layers and / or at least one step of Adjustment of the properties of or materials by temperature treatment includes. Method according to one of the preceding claims, characterized in that the shaped body of more than a page, in particular circulating or enclosing of four or five or all sides are coated, where each assigned two sides of an independent spatial direction are. Component, in particular air turbine component manufactured according to one of the methods of the preceding claims and / or with a coating of the surface of a cavity in an almost closed or inaccessible cavity a hollow body.

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