DE102017210909A1 - Method for the additive production of a component by means of auxiliary structure - Google Patents

Abstract

The invention relates to a process for the additive production of a component (10) by a selective sintering and / or melting process, comprising, during the additive construction a) of the component (10) of a powdered component material (2), the introduction c) of a prefabricated one Auxiliary structure (20) in the additive structure (10), wherein the auxiliary structure (20) serves as a support for subsequently applied to the auxiliary structure (10) layers of the component material (2) and wherein the material of the auxiliary structure (20) is selected during the sintering and / or melting process to remain dimensionally stable.

Description

The present invention relates to a method for the additive production of a component by a selective manufacturing method, in particular a sintering and / or melting method and a correspondingly produced component.

The component is preferably intended for use in a turbomachine, preferably in the hot gas path of a gas turbine. The component is preferably made of a nickel-based or superalloy, in particular a nickel- or cobalt-based superalloy. The alloy may be precipitation hardened or precipitation hardenable.

Generative or additive manufacturing processes include, for example, as powder bed processes, selective laser melting (SLM) or laser sintering (SLS), or electron beam melting (EBM). Laser deposition welding (LMD) is also one of the additive processes.

A method for selective laser melting is known, for example EP 2 601 006 B1 ,

Additive manufacturing processes (English AM: "additive manufacturing") have proven to be particularly advantageous for complex or complicated or filigree designed components, such as labyrinthine structures, cooling structures and / or lightweight structures. Although there may be hardly any restrictions on the design degrees of freedom in the additive manufacturing or 3D printing of plastic components, the production process for complicated and heavy-duty metal components is limited by the fact that large overhangs or cavities are not produced due to the construction direction determined by powder bed-based processes can be.

In particular, the additive manufacturing is further advantageous by a particularly short chain of process steps, since a manufacturing or manufacturing step of a component can be done directly on the basis of a corresponding CAD file.

Furthermore, the additive manufacturing is particularly advantageous for the development or production of prototypes, which can not or can not be produced efficiently, for example, by means of conventional subtractive or machining processes or casting technology.

One problem that constantly arises, especially in the powder bed-based production of complex metal components by SLM or EBM, is the difficulty, as described above, of providing overhangs or overhanging structures or undercuts in the corresponding component or component. The powder bed-based production of metallic components with wide or steeply overhanging areas or surfaces, the surface normal with a mounting direction, for example, includes an angle of more than 45 °, is currently not possible or only with very large compromises in terms of structural and surface quality of the components.

It is therefore an object of the present invention to provide means which allow the components to be provided with respective overhanging areas while still taking advantage of additive manufacturing.

This object is solved by the subject matter of the independent patent claims. Advantageous embodiments are the subject of the dependent claims.

One aspect of the present invention relates to a method for additive production of a component by a selective sintering and / or melting process, comprising during the additive construction of the component of a powdery component material, i. Preferably between the construction of individual layers for the component, the introduction of a prefabricated, preferably ceramic auxiliary structure in the additive structure, wherein the auxiliary structure serves as a support for subsequently applied to the auxiliary structure layers of the component material, and wherein the material (and preferably the design) the auxiliary structure is chosen to remain dimensionally stable during the sintering and / or melting process.

The component material is preferably a base material for the component.

The term "structure" is intended herein to designate the component itself, preferably at any time during its additive production.

By means of the method described, it becomes possible-via the introduction of the auxiliary structure-to be able to define or form overhangs. Such an overhang can be defined by cavities. Thereby, the freedom of geometry according to components to be produced is decisively increased, since in particular even large cavities or undercuts can be produced.

In one embodiment, the auxiliary structure acts as a support structure for supporting a component overhang.

In one embodiment, the auxiliary structure acts as a shield for the particular thermal Shielding further, possibly previously introduced into the structure components, such as functional components, such as sensors. For this embodiment, these components can be particularly useful from harmful thermal effects are preserved.

In one embodiment, the auxiliary structure comprises a ceramic material.

In one embodiment, the auxiliary structure consists of a ceramic material.

In one embodiment, the auxiliary structure for the intended purpose of the component remains in the component. In other words, the auxiliary structure is not removed after the actually additive structure of the component from the component material.

In an alternative embodiment, the auxiliary structure after the additive structure of the component, for example, by a selective method, for example, a chemical etching process, removed from the (actual) component or removed therefrom.

In one embodiment, prior to introducing the auxiliary structure into the additive structure, the method comprises partially removing pulverulent component material from a region of the structure, for example from a powder bed, into which the auxiliary structure, preferably subsequently, is to be introduced.

Another aspect of the present invention relates to a component which can be produced or produced according to the method described, furthermore comprising at least one overhang which has or includes an overhang angle of more than 45 ° relative to a mounting direction.

In one embodiment, the component further comprises below a surface thereof a functional component, such as a sensor, for example a force, pressure, strain, vibration, temperature or sound sensor or another sensor.

Embodiments, features and / or advantages which in the present case relate to the method may also relate to the component or vice versa.

Further details of the invention are described below with reference to the figures.

The 1 to 4 indicate in each case by means of schematic sectional views of an additive manufacturing process.

5 shows a schematic flow diagram, which describes method steps of the present method.

In the exemplary embodiments and figures, identical or identically acting elements can each be provided with the same reference numerals. The illustrated elements and their proportions with each other are basically not to be regarded as true to scale, but individual elements, for better representation and / or better understanding exaggerated be shown thick or large.

1 illustrates an additive, powder bed-based building process of a component 10 on a building board 1 , The component 10 is preferably currently in its additive production. The component 10 is preferably along a construction direction AR from a powder bed 2 constructed of a powdery component material. This is preferably done by alternately coating a manufacturing surface (not explicitly marked) and correspondingly solidifying the applied component layers by means of an energy beam, preferably a laser beam (not explicitly indicated in the figures). The coating described is preferably carried out with a squeegee or a slider, which newly coated the manufacturing surface in layers with a thin powder layer of, for example, about 40 microns thick. Exposing and melting of the powder with the energy beam expediently then takes place only at the points which are to be solidified according to the individual geometry of the component.

The component 10 out 1 has a recess in the upper left area 12 on. The recess 12 was preferably formed by the fact that the component material was no longer exposed in this area with an energy beam. Dashed lines in 1 is an overhang angle α, which is a possible overhang 11 (see 4 below) in the final geometry of the component 10 of about 45 °. In this case, a surface normal of the overhang preferably includes the overhang angle α with the construction direction AR.

2 shows in contrast to 1 in that powdered component material 2 or powder from the recess 12 , For example, was removed by suction.

3 continues to point in contrast to 2 at that in the area of the recess 12 , which was previously freed from powder, an auxiliary structure 20 was introduced. The auxiliary structure 20 is preferably directly in the structure or in the recess 12 inserted. This is expediently such that under the auxiliary structure 20 - And later, for example, completely from the component material 2 enclosed - a cavity 30 or another functional component remains (see also 4 ). In other words, the auxiliary structure acts 20 which preferably keeps its shape stable throughout the process as a bridge across the cavity or channel or component.

Preferably, the dimension of the auxiliary structure defines the dimension of an overhang later provided for the component (see reference numeral 11 in 4 ).

In the cavity 30 For example, in the case of a component applied in the hot gas path of a gas turbine, it may be a cooling channel. The dimensions of the cavity 30 are preferably chosen such that it can not be manufactured by conventional additive manufacturing due to the involved overhanging areas.

4 illustrated as being at the introduction of the auxiliary structure 20 in the additive construction subsequent step, the further additive structure of the component from the component material 2 so that the material still built up the overhang 11 of the component forms. A welding or a cohesive or metallurgical bonding of the auxiliary structure 20 with the component material 2 expediently takes place after introduction of the auxiliary structure 20 and during the further additive construction, in particular the solidification of the first layer or layer of component material 2 on the auxiliary structure 20 ,

The auxiliary structure thus preferably acts as a carrier for further component material to be applied 2 ,

According to 4 It may be the reference 30 instead of a cavity and a functional component, for example, a sensor component, such as a force, pressure, strain, vibration, temperature or sound sensor or another sensor act. In addition to its supporting action, the auxiliary structure functions 20 preferably further as a thermal shield for the sensor, so that the auxiliary structure protects it during the additive construction from the high temperatures and temperature gradients involved, for example a laser melting process.

The auxiliary structure 20 can consist of a ceramic.

The auxiliary structure 20 may further comprise only partially a ceramic.

Furthermore, the auxiliary structure 20 for the intended purpose of the component or its application, remain in the additive structure. Alternatively, the component may, for example, define a cavity under the overhang 11 , in particular by a selective chemical process from the (additive) structure again removed or removed.

• Schritt a) beschreibt den eigentlichen additiven Aufbau des Bauteils 10 (vergleiche 1 bis 4).
• Schritt b) beschreibt vorzugsweise das selektive Entfernen von Bauteilmaterial 2 im Bereich der Ausnehmung 12 (vergleiche 2).
• Schritt c) beschreibt das Einbringen der Hilfsstruktur 20 in den additiven Aufbau wie anhand von 3 beschrieben.
• Schritt d) beschreibt das mögliche Herauslösen der Hilfsstruktur 20 aus dem Bauteil 10, beispielsweise durch eine selektives Ätzverfahren nach dem eigentlichen additiven Aufbau des Bauteils 10 aus dem Bauteilmaterial 2.

5 indicates, with reference to a schematic flowchart, method steps of the present method:

• Step a) describes the actual additive structure of the component 10 (see 1 to 4 ).
• Step b) preferably describes the selective removal of component material 2 in the region of the recess 12 (see 2 ).
• Step c) describes the introduction of the auxiliary structure 20 in the additive construction as based on 3 described.
• Step d) describes the possible detachment of the auxiliary structure 20 from the component 10 , For example, by a selective etching process after the actual additive structure of the component 10 from the component material 2 ,

The invention is not limited by the description based on the embodiments of these, but includes each new feature and any combination of features. This includes in particular any combination of features in the patent claims, even if this feature or combination itself is not explicitly stated in the patent claims or exemplary embodiments.

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

• EP 2601006 B1 [0004]

Claims (10)

Method for the additive production of a component (10) by a selective sintering and / or melting process, comprising, during the additive construction a) of the component (10) of a powdered component material (2), the introduction c) of a prefabricated auxiliary structure (20) in the additive structure (10), wherein the auxiliary structure (20) serves as a support for subsequently applied to the auxiliary structure (10) layers of the component material (2), wherein the material of the auxiliary structure (20) is selected during the sintering and / or melting process to remain dimensionally stable. Method according to Claim 1 , wherein the auxiliary structure (20) acts as a support structure for supporting a component overhang (11). method Claim 1 or 2 wherein the auxiliary structure (20) functions as a shield for thermal shielding of further components introduced into the structure (10), for example functional components (30), such as sensors. Method according to one of the preceding claims, wherein the auxiliary structure (20) comprises a ceramic material. Method according to one of the preceding claims, wherein the auxiliary structure (20) consists of a ceramic material. Method according to one of the preceding claims, wherein the auxiliary structure (20) for the intended purpose of the component (10) remains therein. Method according to one of Claims 1 to 5 , wherein the auxiliary structure (20) after the additive structure of the component (10), for example by a selective method, dissolved out of this (d)) or removed therefrom. Method according to one of the preceding claims, comprising - before introducing the auxiliary structure into the additive structure - the partial removal (b)) of powdered component material (2) from a region of the structure in which the auxiliary structure (20) is to be introduced. Component (10) which is produced or producible according to one of the preceding claims, furthermore comprising at least one overhang (11) which has an overhang angle (α) of more than 45 ° relative to a construction direction (AR). Component (10), which is produced or producible according to one of the preceding claims, further comprising below a surface (13) of the component (10), a functional component (30).

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