A powder bed additive manufacturing system

Abstract

This invention relates to a base body (2), at least one table (3) arranged on the base body (2) on which the powders (T) can be deposited and processed, several layers (4) formed by sintering or fusing the powders (T) deposited on the table (3), at least one energy source (5) located on the base body (2) which applies energy to the powders (T) deposited on the table (3), thereby enabling the production of layers (4), and at least one control unit (6) which enables the production of the layers (4) according to the parameters specified by the users.

Description

[0001] The invention relates to a system that performs additive manufacturing in the powder bed.

[0002] Additive manufacturing is a production process that enables the creation of three-dimensional parts and / or prototypes. It involves using a three-dimensional geometric model, subjecting suitable powders or thin wires to energy with a printer tip, and combining them in layers. Additive manufacturing is used in the production of metal, ceramic, or polymer materials. The ability to create the desired design with this production process allows for the production of parts with complex geometries that cannot be manufactured using conventional production methods. Within the rapidly developing field of aerospace technologies, the production of materials using additive manufacturing technology is gaining increasing importance.

[0003] In additive manufacturing, support structures are used to create unstable parts and prevent molten powder from moving or becoming damaged. The support structure serves to hold the main structure in place and prevent problems such as collapse and wear that can occur in the main structure. Support structures not only play a role in supporting the overhang structure but also in maintaining thermal balance to eliminate residual stresses. Support structures used for thermal purposes help reduce wear phenomena such as cracks, wrinkles, sagging, delamination, and shrinkage. Overhang parts manufactured without support will experience wear phenomena. Parts manufactured using conventional methods require post-processing to bring the part into its final shape.

[0004] German patent application number DE102016224060A1 describes a method for additively manufacturing a protruding component that must be supported by a support structure during additive manufacturing. A method for producing a protruding component that must be supported by a support structure during additive manufacturing is disclosed. A manufacturing area is disclosed that includes a component area and a protrusion area, wherein the component area of ​​the layer is selectively irradiated with an energy beam having a first energy density, and the protrusion area is irradiated with a second energy density that differs from the first energy density.

[0005] Using a powder bed-based additive manufacturing system developed with this invention, the separation of the support structure from the main structure in parts with an overhang structure produced by additive manufacturing is achieved without mechanical processing.

[0006] An aim of this invention is to enable the transfer of heat flow between the support structure and the main structure in parts with overhang structures produced by additive manufacturing, thus preventing the formation of negative thermomechanical effects such as deformation and torsion in the main structure.

[0007] Another objective of this invention is to ensure that overhang parts produced by additive manufacturing can be manufactured precisely, without post-processing, and with minimal deformation.

[0008] To achieve the object of the invention, the powder bed-based additive manufacturing system defined in the first claim and the claims dependent on this claim comprises a base body and a table located on the base body. Powders are distributed and processed on the table. Layers are formed by sintering or melting the powders distributed on the table. Production can be carried out using manufacturing processes such as selective laser sintering on the table, direct metal deposition, and electron beam melting. At least one energy source is located on the base body. The energy source introduces energy into the powders lying on the table. The energy source can preferably be a laser, an electron beam, or an arc. Powder exposed to energy forms layers.In the powder bed-based additive manufacturing system, there is a control unit that allows the part to be manufactured according to the parameters specified by the user.

[0009] The powder-bed-based additive manufacturing system of the invention comprises a part manufactured at least partially by stacking layers using the additive manufacturing method. While the part is being manufactured, the support element is manufactured using the additive manufacturing method to support the overhanging portion of the part and to manufacture it without distorting its geometry. The part and the support element are manufactured from layers. The energy source delivers the energy to the number of layers of the support element specified by the manufacturer, with the energy density decreasing. The layers of the support element are manufactured with different energy densities toward the layer where the support element comes into contact with the part.This allows the support element to be easily separated from the component after the support element and the component have been fully manufactured, without the need for any mechanical processing. A control unit allows the creation of layers with different energy densities, with the data input by the manufacturer. The control unit allows the energy source to gradually apply energy.

[0010] In one embodiment of the invention, the powder-bed additive manufacturing system comprises a support element that is manufactured simultaneously with the component. The component and the support element are manufactured as a single piece, and when production is complete, the support element is separated from the component, thus obtaining the finished component.

[0011] In one embodiment of the invention, the powder-bed-based additive manufacturing system comprises a control unit that enables the production of layers by changing the power and / or speed parameters of the energy source. With the help of the control unit, the layers are produced during the production of the support element with different energy densities specified by the manufacturer. The number of layers of the support element specified by the manufacturer is supplied with different energy levels by the energy source.

[0012] In one embodiment of the invention, the powder-bed-based additive manufacturing system comprises a control unit that ensures that, starting from the layer in which the support element supports the component, the component itself is manufactured in a number of layers specified by the manufacturer with increasing energy density, while the remaining part of the component is manufactured. The part of the component that is manufactured on the support element after contact with the support element is manufactured with a gradually increasing energy density in a number of layers specified by the manufacturer and with a constant energy density after a layer specified by the manufacturer. In this way, the component can be separated from the support element without post-processing.

[0013] In one embodiment of the invention, the powder bed-based additive manufacturing system comprises a control unit that enables both the support element and the component to be produced from layers with gradually changing energy densities. Production takes place with decreasing energy intensity in the number of layers of the support element specified by the manufacturer. The layers of the support element are produced with gradually decreasing energy intensity up to the layer in which the support element contacts and supports the component. Starting from the layer of the support element that comes into contact with the component and thus supports it, components continue to be produced on this layer. In the section of the component that is still being produced, layers with increasing energy density are produced up to a layer specified by the manufacturer.From this layer, which is specified by the manufacturer, production proceeds with a constant energy intensity until the component is completely manufactured. This allows the component to be easily separated from the support element, and after separation, the surface quality of the finished component is better than with conventional processes.

[0014] In one embodiment of the invention, the powder-bed-based additive manufacturing system comprises a transition structure made up of layers between the component and the support element. Almost every layer of the transition structure contains layers with gradually changing energy densities, as specified by the manufacturer. The transition structure allows both the component and the support element to be easily separated without deformation of the component once the component and the support element are fully manufactured, thus achieving manufacturing with high geometric accuracy and good surface roughness.

[0015] In one embodiment of the invention, the powder-bed-based additive manufacturing system comprises a transition structure and a powdered layer within the component where the component comes into contact. Since the layer in the component where the component and the support element come into contact is in powder form, the support element can be removed from the component without the need to apply force.

[0016] In one embodiment of the invention, the powder bed-based additive manufacturing system comprises a support element manufactured at a constant energy density and a transition structure manufactured at variable energy densities. The support element is manufactured at the same constant energy density as the component. A transition structure is manufactured on the support element. Layers with a transition structure are manufactured at different energy densities specified by the manufacturer.

[0017] In one embodiment of the invention, the powder-bed-based additive manufacturing system comprises components manufactured for use in aircraft and / or spacecraft. The component is manufactured with a precision suitable for use in aircraft and / or spacecraft.

[0018] The powder bed-based additive manufacturing system used to achieve the objective of this invention is illustrated in the attached figures. In these figures: Fig. 1 - schematic representation of the “powder bed-based additive manufacturing system”. Fig. 2 - is the perspective view of the component and the support element. Fig. 3 - is the schematic view of the transition element, which consists of layers with gradually changing energy densities.

[0019] The components in the figures are individually numbered and the correspondences of these numbers are given below. 1. Powder bed-based additive manufacturing system 2. Basic body 3. Table 4th layer 5. Energy source 6. Control unit 7. Component 8. Support element 801. Transitional structure (Ü) Powder

[0020] The powder bed-based additive manufacturing system (1) comprises a base body (2), at least one table (3) arranged on the base body (2) onto which the powders (T) can be deposited and processed, a plurality of layers (4) formed by sintering or fusing the powders (T) deposited on the table (3), at least one energy source (5) located on the base body (2) and applying energy to the powders (T) deposited on the table (3), thereby enabling the production of layers (4), and at least one control unit (6) enabling the layers (4) to be produced according to the parameters specified by the user. Fig. 1)

[0021] The powder bed-based additive manufacturing system (1) which is the subject of the invention comprises at least one component (7) which is at least partially manufactured by stacking layers (4) using the additive manufacturing method, at least one support element (8) which is manufactured to support the portion of the component (7) which needs to be supported while the component (7) is manufactured, an energy source (5) which energizes the number of layers (4) of the support element (8) with decreasing energy densities as specified by the manufacturer, and a control unit (6) which enables the production of layers (4) with different energy densities using the data entered by the manufacturer. Fig. 2)

[0022] The powder bed-based additive manufacturing system (1) comprises a base body (2) and at least one table (3) arranged on the base body (2), on which powder (T) can be deposited and processed. The powder (T) deposited on the table (3) is sintered or melted by the energy source (5). In this way, more than one layer (4) is produced. At least one energy source (5) is located on the base body (2), which applies energy to the powder (T) deposited on the table (3). The energy source (5) enables the production of layers (4) by supplying energy. There is a control unit (6) that enables the layers (4) to be produced according to the parameters specified by the user.

[0023] By depositing the layers (4) on top of each other, a component (7) is produced. If an overhang structure of the component (7) arises during production of the component (7), a support element (8) is produced to support this part. The energy source (5) provides energy to the layers (4) in such a way that the number of layers (4), which is specified by the manufacturer, has decreasing energy densities while the support element (8) is produced. There is a control unit (6) that enables the production of layers (4) with different energy densities based on the data entered by the manufacturer.

[0024] In one embodiment of the invention, the powder-bed-based additive manufacturing system (1) comprises the support element (8), which is manufactured simultaneously with the component (7). The component (7) and the support element (8) are manufactured simultaneously, and when production is complete, the support element (8) is separated from the component (7) and discarded by the manufacturer.

[0025] In one embodiment of the invention, the powder bed-based additive manufacturing system (1) comprises a control unit (6) that enables the layers (4) to be produced with energy densities specified by the manufacturer by changing the power and / or speed parameters of the energy source (5). With the aid of the control unit (6), the layers (4) that form the support element (8) are produced such that they have different energy densities specified by the manufacturer. By changing the parameters of the energy source (5), such as the scanning strategy, the beam diameter, the translation parameter, and the hatching spacing, layers (4) with different desired energy densities are produced.

[0026] In one embodiment of the invention, the powder bed-based additive manufacturing system (1) comprises the control unit (6), which enables the production of the number of layers (4) specified by the manufacturer with gradually increasing energy density and at constant energy density after a layer (4) specified by the manufacturer, while the component (7) is being produced. In the section of the component (7) that is produced on the layer (4) in contact with the support element (8), a number of layers (4) specified by the manufacturer with gradually increasing energy density are produced. After a layer (4) specified by the manufacturer, the remaining section of the component (7) that needs to be produced is produced with constant energy density. In this way, the support element (8) has the desired geometric precision and surface roughness after separation from the component (7).

[0027] In one embodiment of the invention, the powder bed-based additive manufacturing system (1) comprises a control unit (6) which controls production with decreasing energy density in a number of layers (4) specified by the manufacturer down to the layer (4) in which a manufactured part of the support element (8) comes into contact with the component (7), production with increasing energy density from the section of the component (7) in contact with the support element (8) up to a predetermined layer (4) of the component (7), and production at constant energy density, starting with this layer (4), until the component (7) is completely manufactured, and thus enables the component (7) to be separated from the support element (8) without post-processing.Production takes place with decreasing energy density in the number of layers (4) specified by the manufacturer towards the layer (4) at which the support element (8) comes into contact with the component (7) and supports the component (7). Starting from the layer (4) of the support element (8) that comes into contact with the component (7) and thus supports the component (7), the component (7) is further manufactured on this layer (4). Layers (4) with increasing energy density are created up to a layer (4) of the component (7) specified by the manufacturer. Starting from this layer (4), which is specified by the manufacturer, production takes place at a constant energy density until the component (7) is completely manufactured. This means that the support element (8) can be separated from the component (7) easily and without additional force, and a higher manufacturing quality is achieved compared to conventional processes.

[0028] In one embodiment of the invention, the powder bed-based additive manufacturing system (1) comprises at least one transition structure (801) produced from layers (4) between the component (7) and the support element (8) and consisting of layers (4) with gradually changing energy densities in almost each layer (4), as specified by the manufacturer. The transition structure (801) minimizes structural defects, such as sagging or deformation of the component (7), when the component (7) is fully manufactured, compared to the overhang regions produced without support, so that the component (7) can be manufactured with high dimensional accuracy. Fig. 3)

[0029] In one embodiment of the invention, the powder-bed-based additive manufacturing system (1) comprises a layer (4) that is produced almost entirely in powder form (T) in the region where the transition structure (801) and the component (7) come into contact. The intermediate layer (4) produced in powder form (T) allows the transition structure (801) to be easily separated from the component (7).

[0030] In one embodiment of the invention, the powder bed-based additive manufacturing system (1) comprises the support element (8) produced at a constant energy density and the transition structure (801) produced at variable energy densities. The support element (8) is produced with a fixed energy density from a number of layers (4) specified by the manufacturer. The transition structure (801) is produced on the support element (8) with varying energy densities from a number of layers (4) specified by the manufacturer. The layers (4) that form the component (7) on the transition structure (801) are further produced.

[0031] In one embodiment of the invention, the powder-bed-based additive manufacturing system (1) comprises components (7) manufactured for use in aircraft and / or spacecraft. The component (7) manufactured using the powder-bed-based additive manufacturing system (1) has tolerances suitable for use in aircraft and / or spacecraft. Manufacturing with gradual energy densities eliminates defects such as twisting, deformation, etc. in the component (7). The finished component (7) manufactured complies with aerospace standards. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This 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

[0000] DE 102016224060A1

[0004]

Claims

[1] A powder bed-based additive manufacturing system (1), comprising a base body (2), at least one table (3) arranged on the base body (2) on which the powders (T) can be deposited and processed, a plurality of layers (4) formed by sintering or fusing the powders (T) deposited on the table (3), at least one energy source (5) arranged on the base body (2) which applies energy to the powders (T) deposited on the table (3), thereby enabling the formation of layers (4), at least one control unit (6) which enables the layers (4) to be produced according to the parameters specified by the user, characterized byin that at least one component (7) is manufactured at least partially by superimposing layers (4) using the additive manufacturing method and at least one support element (8) is manufactured to support the part of the component (7) that needs to be supported while the component (7) is manufactured, wherein an energy source (5) energizes the number of layers (4) of the support element (8) with decreasing energy densities specified by the manufacturer, and wherein the control unit (6) enables the production of layers (4) with varying energy densities with the data entered by the manufacturer. [2] Powder bed-based additive manufacturing system (1) according to claim 1, characterized by that a support element (8) is produced at the same time as the component (7). [3] Powder bed-based additive manufacturing system (1) according to claim 1 or 2, characterized bythat the control unit (6) enables the production of the layers (4) with energy densities specified by the manufacturer by changing the power and / or speed parameters of the energy source (5). [4] Powder bed-based additive manufacturing system (1) according to one of the preceding claims, characterized by that the control unit (6) ensures the production of the number of layers (4) specified by the manufacturer with gradually increasing energy density during the production of the component (7), starting with the layer (4) in which a manufactured part of the support element (8) touches the component (7) and supports the component (7), and the production with constant energy density after a layer (4) specified by the manufacturer. [5] Powder bed-based additive manufacturing system (1) according to one of the preceding claims, characterized bythat the control unit (6) manufactures with decreasing energy density in a number of layers (4) specified by the manufacturer down to the layer (4) in which a manufactured part of the support element (8) comes into contact with the component (7), manufactures with increasing energy density from the section of the component (7) that is in contact with the support element (8) up to a predetermined layer (4) of the component (7) and manufactures at constant energy density, starting with this layer (4), until the component (7) is completely manufactured, and thus enables the component (7) to be separated from the support element (8) without post-processing. [6] Powder bed-based additive manufacturing system (1) according to one of the preceding claims, characterized byin that it comprises at least one transition structure (801) made of layers (4) between the component (7) and the support element (8), consisting of layers (4) with gradually changing energy densities in almost each layer (4), as specified by the manufacturer. [7] Powder bed-based additive manufacturing system (1) according to claim 6, characterized by that it comprises a layer (4) which is produced almost entirely in powder form (T) in the region in which the component (7) comes into contact with the transition structure (801). [8] Powder bed-based additive manufacturing system (1) according to claim 6 or 7, characterized by that it comprises: the support element (8) which is manufactured with constant energy density, and the transition structure (801) which is manufactured with variable energy densities. [9] Powder bed-based additive manufacturing system (1) according to one of the preceding claims, characterized bythat the component (7) is manufactured for use in aircraft and / or spacecraft.

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