DE102019209020A1 - Support structure, computer program product and method for removing the support structure - Google Patents

Abstract

A support structure (1) for supporting a component area (10) in the additive, in particular powder-bed-based, production of the component (10) is specified. The support structure comprises a volume support area (2) with a connecting element (3) for forming a positive connection with a tool (20), and a contact area (5) for structurally connecting the volume support area (2) to the component area (10) during additive manufacturing the component area (10). Furthermore, a corresponding computer program product and a method for removing the support structure (10) from the component area (10) are specified, wherein the method, a), the provision of a support structure (10), b), the production of the connecting element (3) in the Volume support area of the support structure (1), c), the connection of a tool (20), having a complementary connection means (23), to the connection element (3), and, d), the separation of the support structure (1) from the component area by ( 10) includes mechanical force (F, R).

Description

The present invention relates to a support structure or an auxiliary structure for supporting a component area or overhanging area in the additive manufacturing of components, in particular by powder-bed-based processes. The invention also relates to a corresponding computer program product and a method for removing the support structure.

Said component area or a corresponding component having this area in turn preferably relates to a component made of a high-temperature-resistant material with a complex composition, in particular for use in the hot gas path of a turbo machine such as a gas turbine. Accordingly, the component can consist of a superalloy, in particular a nickel- or cobalt-based superalloy. The alloy can furthermore be precipitation hardened or precipitation hardenable. Due to its potential to disrupt industry, generative or additive manufacturing is also becoming increasingly interesting for the series production of the above-mentioned turbine components, such as turbine blades or burner components. Alternatively, the component or component area can be other components, for example components used in the automotive or aviation area.

Additive manufacturing processes include, for example, powder bed processes such as selective laser melting (SLM) or laser sintering (SLS), or electron beam melting (EBM).

Further additive processes are, for example, “Directed Energy Deposition (DED)” processes, in particular laser deposition welding, electron beam or plasma powder welding, wire welding, metallic powder injection molding, so-called “sheet lamination” processes, or thermal spray processes (VPS LPPS, GDCS).

Such additive processes have also proven to be particularly advantageous for complex or filigree components, for example labyrinth-like structures, cooling structures and / or lightweight structures. In particular, additive manufacturing is advantageous due to a particularly short chain of process steps, since a manufacturing or manufacturing step of a component can largely take place on the basis of a corresponding CAD file and the selection of corresponding manufacturing parameters.

A method for the additive manufacture of a component with support structures is known from, for example GB 2458745 B .

Despite great degrees of freedom per se with regard to the shaping of additively manufactured parts, component sections or components, there are restrictions on the additive formation of overhanging areas or inner cavities or cavities, especially larger cooling channels, in particular with high-strength, high-temperature-resistant or other highly resilient materials. In the case of powder bed-based manufacturing processes (“powder bed fusion”), the component to be manufactured is built up along a fixed, predetermined assembly direction (vertical Z-direction). Each component area, which now forms an overhang with regard to the direction of construction, must be supported by so-called support structures at certain or supercritical overhang angles in order to enable a stable process. At least as important as mechanical support in the powder bed is the heat dissipation, which, due to the quasi-thermal insulating powder bed, can practically only take place via a substrate or mounting plate. Selective beam melting processes represent welding processes which, depending on the selected parameters, can have very high local temperature gradients of sometimes more than 10 ⁶ K / s due to the strong beam focusing.

Both a too weak heat input via beam power or laser power that is too low, for example, can have a negative effect on the structure of the component, as can an excess of energy which can be introduced into the powder and only insufficiently removed again. The support structure therefore also has the important task of dissipating the heat introduced during additive manufacturing.

Another problem is that the support structures, which are made of the same materials when building high-strength components, can hardly be processed mechanically and are therefore very difficult to remove again afterwards.

It is therefore an object of the present invention to provide an improved support structure which fulfills the above-mentioned objects and, in particular, can be removed again relatively easily by subsequent means. It is also an object of the present invention to remove the described support structure simply and efficiently, for example in just a few reworking steps.

This object is achieved by the subject matter of the independent patent claims. Advantageous refinements are the subject of the dependent claims.

One aspect of the present invention relates to a support structure or auxiliary structure for Support of a component area, in particular an interior component area or a cavity-defining component area in the additive, particularly powder-bed-based, production of the component.

In the present case, the component area preferably relates to a part of the component that must be mechanically supported for additive manufacturing, since it forms or defines an overhang. The component area preferably defines an inner cavity of the component or - in the finished component - a cooling channel, the upper part of which, for example due to its expansion, can only be built up with support structures.

The method comprises a, preferably structurally solid and / or dimensionally stable, volume support area with a connecting element for forming a form-fitting connection, for example if a tool is subsequently connected to the connecting element.

The connecting element is preferably an element which is designed to form a detachable connection, for example via a form fit and / or force fit with a further, complementary connection element of the tool. This can be a screw connection, a tongue and groove connection, a tooth coupling or another connection.

The support structure furthermore comprises a contact area for structurally connecting the volume area to the component area during the additive production of the component area or the component. The contact area preferably designates a surface area of the volume support area.

The structural or material connection is preferably carried out by means of additive manufacturing itself.

The described volume support area of the support structure advantageously creates an area via which the support structure can be removed again in a simple manner by applying mechanical forces. In other words, a force applied to the volume support structure, for example by means of an external tool, can be particularly expediently transferred in this way and the support structure can thus be removed uniformly or homogeneously without damaging the component area.

Via the contact area and / or a contact support area described below, the structural connection of the support structure to the component area can subsequently be released again particularly easily and efficiently, i.e. especially destroyed. The contact area can furthermore comprise extensions or parts of a contact support area.

In one embodiment, the connecting element is a form-fitting connecting element, i. a connecting element which is designed to enter into a positive connection with a further, complementary connecting element.

In one embodiment, the connecting element comprises a thread, a bayonet locking element, a tongue and groove connecting element or a toothed coupling element.

The named “elements” expediently form a functional part which can form a corresponding connection with a corresponding complementary connecting element or part of the tool (compare the mentioned tongue groove connection, bayonet connection or tooth coupling).

In one embodiment, the component region comprises or defines an overhanging region of the component, a cavity or a channel of the component to be additively manufactured, for example a cavity thereof.

The expression “overhang” or “overhanging area” can mean in the present case that a surface or surface tangent forms a slope or an angle of more than 90 ° relative to a production plane.

In one configuration, the support structure has internal lattices or lattice structures within the volume support area. However, these lattices or lattice structures preferably do not impair the dimensional stability of the volume support area, but advantageously only allow a more economical additive structure.

In one configuration, the support structure is designed to mechanically support the component region during additive manufacturing (of the component and the support structure).

In one configuration, the support structure is designed to thermally couple the component area to a substrate or a construction platform during additive manufacturing. This advantageously improves the dissipation of heat from the additively constructed structures, since heat exchange via the substrate with the environment is made possible. This in turn can prevent or limit the likelihood of hot cracks or crack centers developing during additive manufacturing.

In one embodiment, the support structure is or will be produced by the same additive method as the component, including the component area.

In one embodiment, the volume support area in the contact area is connected to the component area via a contact support area during additive manufacturing, the contact support area being structurally weaker than the volume support area. As indicated above, this configuration advantageously enables the support structure to be mechanically removed from the component region, such as, for example, the support structure breaking out of a component cavity.

Another aspect of the present invention relates to a computer program product comprising geometry or design information of the support structure, for example in the form of a CAD file, the computer program product further comprising commands that initiate a data processing device and / or a computer-aided additive manufacturing system when executing a corresponding program to build the support structure as part of an additive manufacturing process.

A computer program product such as a computer program means, for example as a (volatile or non-volatile) storage medium, e.g. a memory card, a USB stick, a CD-ROM or DVD, or also in the form of a downloadable file from a server in a network can be provided or included. The provision can also take place, for example, in a wireless communication network by transmitting a corresponding file with the computer program product or the computer program means. A computer program product can include program code, machine code, G-code and / or executable program instructions in general.

Another aspect of the present invention relates to a method for removing or separating the support structure from the additively, in particular powder-bed-based, manufactured component area, in particular from an inner component area, such as a cavity, of the component. The method comprises the provision of the support structure, preferably in an additive manner, during the production of the component.

The method further includes the production of the, in particular form-fitting, connecting element in the volume support region of the support structure.

The method further comprises connecting a tool having a complementary connecting element to the described connecting element and separating the support structure from the component region by the action of mechanical force.

In one embodiment, the mechanical force or force includes a relative torsion or rotation between the support structure and the component area.

In one embodiment, the mechanical force action comprises a (mechanical) pulling movement or translation between the support structure and the component area, to the effect that the support structure can be separated from the component area.

In one embodiment, the mechanical action of force comprises a relative torsion as well as a (mechanical) pulling movement or translation between the support structure and the component area.

As a result of these described configurations, the support structure can subsequently be separated or detached from the component area in a particularly simple, efficient and non-destructive manner for the component.

In one embodiment, the connecting element is produced additively, in particular an internal thread or a bayonet locking element or part of a tongue and groove connection or tooth coupling is produced additively. This configuration advantageously makes it possible to dispense with further conventional processing steps for producing the connecting element following the additive production.

In one embodiment, the connecting element is produced, in particular conventionally, by making a threaded hole in the volume support area. This configuration can also simplify the removal of the support structure as a whole since, for example, no such complex additive manufacturing is required.

In one embodiment, the connecting element comprises a threaded hole, again comprising an internal thread.

In one embodiment, the complementary connecting means comprises a threaded pin, which can be screwed into the described internal thread, in particular to remove the support structure.

In one embodiment, the support structure is cooled via the tool or in some other way after the connection or before the separation of the support structure. Accordingly, the tool can comprise a corresponding cooling device, such as a cooling channel, or be formed in some other way To put the support structure under thermal prestress. This advantageously enables mechanical contraction or shrinkage of the support structure, which firstly prefers the removal of the support structure and furthermore minimizes surface damage to the component area. The cooling can be accomplished, for example, via a fluid such as liquid nitrogen or other media.

Refinements, features and / or advantages that can relate to the support structure or the computer program product, furthermore relate to the described method for removing the support structure from the component area, or vice versa.

Further features, properties and advantages of the present invention are explained in more detail below on the basis of exemplary embodiments with reference to the accompanying figures.

All the features described so far and below are advantageous both individually and in combination with one another. It goes without saying that other embodiments can be used and structural or logical changes can be made without departing from the scope of protection of the present invention. The following description is therefore not to be interpreted in a restrictive sense.

As used herein, the term "and / or" when used in a series of two or more items means that any of the listed items can be used alone, or any combination of two or more of the listed items can be used.

• 1 deutet anhand eines schematischen Längsschnitts eine Stützstruktur gemäß der vorliegenden Erfindung an.
• 2 deutet anhand eines schematischen Querschnitts eine Stützstruktur gemäß der vorliegenden Erfindung an.
• 3 deutet anhand eines Längsschnitts Einzelheiten der Stützstruktur gemäß 2 an.
• 4 zeigt ein schematisches Flussdiagramm, welches erfindungsgemäße Verfahrensschritte andeutet.

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

• 1 indicates a support structure according to the present invention on the basis of a schematic longitudinal section.
• 2 indicates a support structure according to the present invention on the basis of a schematic cross section.
• 3 indicates details of the support structure according to a longitudinal section 2 at.
• 4th shows a schematic flow diagram which indicates method steps according to the invention.

In the exemplary embodiments and figures, elements that are the same or have the same effect can each be provided with the same reference symbols. The elements shown and their proportions to one another are fundamentally not to be regarded as true to scale; rather, individual elements can be shown exaggeratedly thick or with large dimensions for better illustration and / or for better understanding.

1 shows sections or regions of a component in a schematic sectional view 10 . The component 10 has a cavity or a cavity 11 on. The one above the cavity 11 shown component area (here also with the reference number 10 marked) accordingly represents an overhang area of the component.

Although this is not explicitly marked in the figures, a geometry of the cavity 11 be round and the component 10 accordingly, for example, have a round or elliptical continuous channel, such as a cooling channel for cooling the component during operation. The dimensions of the cavity 11 or a corresponding cavity can in the finished component 10 , preferably at least 5 mm in diameter.

The component is preferably a component which is used in the hot gas path of a turbo machine, for example a gas turbine. In particular, the component can be a rotor or guide vane, a segment or ring segment, a burner part or a burner tip, a frame, a shield, a heat shield, a nozzle, a seal, a filter, a mouth or lance, a resonator, punch or a Whirler designate, or a corresponding transition, insert, or a corresponding retrofit part.

Accordingly, the component is preferably made from a highly temperature-resistant, in particular highly heat-resistant material such as a superalloy. For the additive structure of the component or the component area 10 In particular, using powder bed-based methods such as selective laser melting or electron beam melting, a corresponding alloy is provided, preferably in powder form, and the component is then solidified and built up in layers by selective irradiation.

In 1 it can be seen that within the cavity 11 a support structure 1 is arranged.

The support structure 1 is provided in particular around the upper part of the component area 10 , which forms an overhang in relation to a construction direction Z, to be supported. The support structure also functions 1 as a heat sink or enables or facilitates the heat exchange or the heat dissipation of process heat during the selective melting, preferably with a laser or electron beam (not explicitly identified).

In the course of additive manufacturing - according to the direction of construction Z - a lower part of the component or component area is initially created 10 (here also with substrate 12th marked) and then the support structure 1 . After completing the support structure 1 in the Z direction, preferably the next or upper (overhanging) component area is consolidated in layers.

The support structure 1 has a volume support area 2 on. The volume support area 2 has an, in particular form-fitting and / or force-fitting, connecting element 3 on. With the connector 3 it is preferably a form of a detachable connecting means, which is designed, for example, to form a screw, clamp, tongue-and-groove connection or another form-fitting connection, for example a bayonet lock or a toothed coupling, if necessary with a further complementary connecting element.

The volume support area 2 advantageously enables in particular the introduction of the connecting element 3 , for example as a threaded hole with an internal thread. It can be seen that the connecting element 3 in the present case can be designed as a bore, in particular a threaded bore (thread not explicitly identified), which extends over an axial length x of the support structure 1 extends.

The length x is preferably greater than half the axial extent of the support structure 1 or the volume support area 2 . Due to the great length or expansion of the connecting element 3 , in particular the threaded hole, can in particular have a large force and / or a large torque when removing the support structure 1 relative to the part area 10 transferred, and the support structure 1 can be removed easily and efficiently.

In a contact area 5 exhibits the support structure 1 preferably a contact support area 6th on. The contact support area 6th or the contact area 5 are for the structural or material connection of the volume support area with the component area 10 set up during additive manufacturing. In other words, the contact support area connects 6th the support structure 1 preferably on all sides with the component area 10 on which the support structure 1 to the component 10 adjoins.

A functional relationship between the volume support area 2 and the contact area 5 or the contact support area 6th advantageously enables a particularly favorable force flow or a favorable force transmission with a subsequent removal of the support area from the component area, which affects the operation or the function of the finished component, for example for the flow through the cavity 11 as a cooling channel with a cooling fluid, is essential.

The contact support area 6th for example, an in 1 Weak structural connection (between component area 10 and support structure 1 ) and / or a type of predetermined breaking point can be formed.

The contact support area 6th is preferably provided in a radially outermost region of the support structure in order to make contact with the component region 10 to build.

The support structure 1 further comprises grids or grid-like structures 7th , which in a radially outer, central area of the support structure 1 , but radially outside of the connecting element 3 , arranged or provided. The grid-like structures 7th serve in the present case to make the additive structure more efficient through less build-up of material mass, but at the same time a sufficient stability of the support structure 1 or the volume support area 2 to offer. These are the case with the support structure 1 four “chambers” with grid-like structures 7th exemplified, which are all radially outside the connecting element 3 are realized.

A connection between the inner part of the volume support area 2 and parts thereof lying further radially on the outside are present via support webs or volume support webs 4th guaranteed.

Furthermore, in 1 already a tool 20th drawn, which according to the method described below is already in the connecting element 3 or is arranged connected to this.

Preferably and as in 1 shown is the tool 20th around a threaded pin via which the tool is positively and / or non-positively connected to the volume support area 2 the support structure 1 is connected (see procedural steps c) further down).

This advantageously allows a simple and efficient separation (compare process step d) below) of the support structure 1 from the component area 10 by mechanical means.

2 shows schematically a cross-sectional view of an embodiment of the support structure according to the invention 1 . For simplicity, the tool is 20th not shown. It can be seen that the cavity 11 round, especially circular, is designed. The support structure 1 is still inside the cavity 11 Arranged over a large cross-sectional area in such a way that the component area 10 is appropriately supported. The round or circular cross-section of the cavity 11 or of the component in the upper area, it is owed that the contact area has individual contact elements or teeth, which are also given the reference number 5 are marked, has different sizes. The contact area 5 also has teeth of different sizes on the underside. Accordingly, the support structure 1 be formed axially symmetrical with respect to a horizontal.

To the support structure by way of the method described in detail below 1 appropriately from the component area 10 to separate, in particular in order to minimize the moment of resistance in the direction of pull (in the illustration of the 2 from the plane of representation), the individual teeth are preferably formed along the assembly direction Z and taper upwards or downwards. This advantageously enables a relatively simple mechanical removal of the support structure and - during construction - an appropriate supporting effect and an appropriate heat removal.

3 indicates - similar to the representation of the 1 - a longitudinal section of the support structure 1 out 2 at. For simplicity, the grids are 7th and the tool 20th also not shown here. In contrast to the representation of the 1 it can also be seen that the individual contact area elements 5 have a length l in the axial direction. Over this length l, the resistance which is used to remove the support structure 1 must be overcome. The greater the length l, the stronger the structural connection of the contact area 5 with the component area 10 and the greater the resistance is likely to be.

Unlike the rest of the 2 and 3 shown, the contact area elements 5 viewed in longitudinal section - similar to in 1 indicated - (pointed), and in cross-section have a certain extension to them in the pulling direction when removing the support structure 1 simply "snap off".

4th indicates method steps according to the invention with the aid of a schematic flow diagram.

The method presented according to the invention is a method for removing a support structure 1 from an additively manufactured component area 10 . The procedure includes, a) , providing a support structure 10 , as described above.

The support structure 1 is expediently built up or manufactured using the same additive process as the component 10 itself. Accordingly, a shape or a design or their information is expediently already provided in the steps preparatory to production, for example in the form of a CAD file. The reference character CPP in the flow chart of FIG 4th a computer program product which comprises the named design information, for example in the form of structural or functional data or information.

Furthermore, the computer program product can comprise instructions which, when a corresponding program is executed by a data processing device or computer-aided additive manufacturing system, cause the support structure to be implemented 10 to be set up as part of an additive manufacturing process.

The method further includes, b) the manufacture of the connecting element 3 in the volume support area 2 the support structure 1 . The connecting element 3 , in particular as a blind hole (threaded hole) comprising a thread, can already be built up as a whole as part of additive manufacturing.

Alternatively, the connecting element 3 in a conventional manner following the provision of the support structure 1 by making a threaded hole in the volume support area 2 getting produced.

The method further includes, c) , connecting the described tool 20th , having a complementary connecting element 23 , with the connector 3 .

According to the embodiment shown of the connecting element 3 as a threaded hole with an internal thread, comprises the connecting means complementary thereto 23 of the tool 20th preferably a threaded pin with an external thread. In 1 is already shown that the tool 20th in the volume support area 2 is screwed in.

In contrast to what is shown here, connections other than screw connections are of course used for connecting the tool 20th with the volume support area 2 conceivable and intended. For example, a simple bayonet connection between the tool 20th and support structure 1 already for an expedient removal of the support structure 1 from the component area 10 sufficient. Other possible connections are clamp connections or teeth (see above).

The method further includes, d) , separating the support structure 1 from the component area by 10 mechanical force. The mechanical force or force can be a relative torsion or rotation R. (compare curved arrows in 1 ) between the support structure 1 and the component area 10 include and / or a mechanical pulling movement F. or translation (compare arrow pointing to the right in 1 ) between the support structure 1 and the component area 10 .

In order to further increase the mechanical force or to apply it more expediently or in a more targeted manner, when removing the support structure 1 , for example to the component areas 10 a counter bracket 21st be set. The counter bracket 21st is in 1 drawn on the right edge and allows a stop against which the support structure 1 out of the cavity 10 can be pulled out or unscrewed.

When separating or removing a (weaker) structure of the contact support area 6th - as with a predetermined breaking point - preferably destroyed or partially torn off. However, this is due to the dimensional stability of the volume support area 2 Over an entire axial extent of the cavity 11 or the support structure 1 particularly homogeneously possible, so that a subsequent mechanical post-processing of the inner surfaces of the cavity after the separation or removal 11 proves to be simple or can even be omitted.

The method according to the invention can optionally also include cooling of the tool 20th , in particular after connecting the same to the connecting element 3 , have (compare process step e) in 4th . For this purpose, the tool can, for example, have a cooling channel 22nd have, which is shown here only in a simplified manner. Before separating the tool 20th accordingly preferably a cooling fluid, for example comprising liquid nitrogen, flows through it. This advantageously causes a contraction or a shrinkage of the structure of the volume support area 2 and sets the support structure 1 still thermally under tension. This in turn makes it easier to remove the support structure 1 and at the same time prevents disadvantageous surface damage to inner surfaces of the component area 10 .

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

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• GB 2458745 B [0006]

Claims (15)

Support structure (1) for supporting a component area (10) in the additive, in particular powder-bed-based, production of a component (10), comprising: - A volume support area (2) with a connecting element (3) for forming a form-fitting connection with a tool (20), - A contact area (5) for structurally connecting the volume support area (2) to the component area (10) during the additive production of the component area (10). Support structure (1) according to Claim 1 wherein the component region (10) comprises an overhanging region, a cavity or a channel of the component (10) to be produced additively. Support structure (1) according to Claim 1 or 2 wherein the connecting element (3) comprises a thread, a bayonet locking element, a tongue and groove connecting element or a tooth coupling element. Support structure (1) according to one of the preceding claims, wherein the connecting element (3) extends over more than half of an extent of the volume support region (2) or projects into it. Support structure (1) according to one of the preceding claims, which has internal lattice structures (7) within the volume support area (2). Support structure (1) according to one of the preceding claims, which is designed to mechanically support the component region (10) during the additive manufacturing and to thermally couple it to a substrate (12). Support structure (1) according to one of the preceding claims, which is produced by the same additive method as the component comprising the component region (10). Support structure (1) according to Claim 7 , the volume support area (2) in the contact area (2) being connected to the component area (10) via a contact support area (6) during additive manufacturing, and the contact support area (6) being structurally weaker than the volume support area (2). Computer program product (CPP), comprising design information, for example in the form of a CAD file, of a support structure (1) according to one of the preceding claims, wherein the computer program product (CPP) further comprises instructions that cause a corresponding program to be executed by a computer-aided additive manufacturing system to build the support structure (10) as part of an additive manufacturing process. A method for removing a support structure (10) from an additively manufactured component area (10), comprising: - a) providing a support structure (10), in particular a support structure (10) according to one of the preceding claims, - b) producing a connecting element (3) in a volume support area of the support structure (1), - c) connecting a tool (20), having a complementary connecting element (23), to the connecting element (3), and - d) Separation of the support structure (1) from the component area by (10) the action of mechanical force (F, R). Procedure according to Claim 10 , wherein the mechanical force action comprises a relative torsion (R) and a mechanical tensile movement (F) between the support structure (1) and the component area (10). Procedure according to Claim 10 or 11 , wherein the connecting element (3) is produced additively. Procedure according to Claim 10 or 11 , wherein the connecting element (3) is produced by making a threaded hole in the volume support area (2). Method according to one of the Claims 10 to 13 wherein the connecting element (3) comprises a threaded hole (3) comprising an internal thread and the complementary connecting means (23) comprises a threaded pin. Method according to one of the Claims 10 to 14th , wherein the support structure (1) is cooled (e) after being connected via the tool (20).

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