Method and device for producing micro parts and micro components by means of additive manufacturing using micro laser sintering

Abstract

The invention relates to a method and a device for producing micro parts and micro components by means of additive manufacturing using micro laser sintering. A pulverulent agglomerating material (1) is applied in layers from a first powder reservoir (2), and the material is melted using laser light (4) after being applied. The invention is characterized in that the material (1) located in the first powder reservoir (2), which is open in the direction of a processing plane, is an agglomerating powder, the particle size (1) of which equals maximally 20 μm, and a force (F1) is applied to the agglomerating material (1) in the direction of a substrate (3) in a process region (100) at least during the application process, the agglomerating material (1) behaving as a fluid while being applied as a result of said force. For this purpose, the device has a horizontally aligned base (5) which is interrupted at least in some regions in a process region (100) above a substrate (3) and has a first powder reservoir (2) which is arranged above the base (5) in a horizontally movable manner over the base (5) and which comprises an interior for receiving a pulverulent agglomerating material (1), the particle size (1) of which equals maximally 20 μm, wherein the first powder reservoir (2) has a first means (6) in the interior thereof for applying a first axial force (F1), which acts in the direction of the base (5) and the substrate (3), to the pulverulent agglomerating material (1) located in the interior, the agglomerating material (1) behaving as a fluid in the process region (100) at least while being applied as a result of said force.

Description

[0001] Method and device for the production of micro-parts and micro-components by additive manufacturing using micro laser sintering

[0002] The present invention relates to a method for producing microparts and microcomponents by additive manufacturing using 3D microprinting and micro laser sintering. According to the preamble of the first patent claim.

[0003] Furthermore, the present invention relates to a device for carrying out the method according to the invention according to the preamble of the 10th patent claim.

[0004] Micro laser sintering is a powder-bed-based additive manufacturing technology often referred to as selective laser sintering or selective laser melting. Micro laser sintering is an industrial technology that provides micro metal parts for various industries.

[0005] Laser sintering is a process in which plastic or metal powder is melted layer by layer using a laser beam without the use of binders, and after the melt has solidified, a homogeneous material of high density is created.

[0006] A 3D CAD model of the target geometry is created for this purpose, containing all the details of the finished component. This CAD model is divided into several cross-sections, called layers. During manufacturing, a thin layer of powder is applied to a substrate. The powder is selectively melted by a laser beam according to each cross-section. The substrate is then lowered, and the process of powder coating, melting, and lowering the platform is repeated layer by layer until the part is finished.

[0007] Micro laser sintering combines the advantages of additive manufacturing with those of micromachining. This process produces micro-metal parts with high precision, detail resolution, and surface quality. These advantages make it possible to produce moving parts and assemblies in a single step. The basis for these outstanding results is the combination of a very small laser beam diameter, special micropowder, and very thin layers.

[0008] The parts are used in all industries that require small metal parts with high precision, smooth surface finish, excellent detail resolution, and complex shapes. Current main industries include medicine, semiconductors, mechanical engineering, aerospace, energy and chemicals, as well as jewelry and watches.

[0009] WO 2018 / 063969 A1 describes a system comprising: a deposition device configured to deposit powder particles onto a substrate; a laser configured to generate a laser beam for irradiating the deposited powder particles; and an optically transparent press configured to exert mechanical pressure on the deposited powder particles during their irradiation by the laser beam, wherein the laser beam irradiates the deposited powder particles through the optically transparent press. A disadvantage is that the pressure exerted during laser irradiation makes it difficult to create structures with an irregular surface because the shape of the manufactured component is already predetermined by the structure of the press.

[0010] CN 113458421 A discloses a system and a method for improving the quality of a powder bed in an additive manufacturing process. The system comprises a spatially displaceable powder scattering device and an excitation unit, wherein the scattering device is arranged for applying one or more powder layers on a processing plane to a substrate platform or a powder bed processed with the system. The excitation unit is arranged to break up clusters and / or adhesions between particles of the individual powder and / or between particles of the individual powder and a powder bed treated with the system, so that the powder scattering device can apply a smooth powder layer to the substrate platform and / or the previous powder layer / bed.

[0011] Powder accumulations are broken up by introducing vibrations that can be generated pneumatically, electromagnetically or by introducing ultrasound.

[0012] Other publications that suggest the introduction of vibrations include DE 10 2016 202 696 B4 and EP 3 292 989 A1.

[0013] The publication DE 11 2008 000 027 T5 discloses a "laminating molding device" with which a high-precision multi-layer article with a compact design can be produced. The prior art cited therein discloses that a lifting table for raising the molding plate and a molding frame enclosing the lifting table are provided. A mold plate is lowered and a lifting table is raised in a single step. The powder has an average particle size of 20 μm; therefore, particles with a size larger than 20 μm are always present, which is unsuitable for some applications.

[0014] The publication DE 10 2016 107 769 A1 concerns additive manufacturing and handling mechanisms for additive manufacturing. It does not address the particle size, and it is not disclosed that an agglomerating powder is used. This solution is intended to allow powder recovery.

[0015] For example, the document DE 10 2017 124 047 A1 discloses a composition for use in additive manufacturing processes in which an anti-agglomeration agent is used to prevent agglomeration of the powder used. This requires increased effort, and these agents can change the chemical composition of the materials used. This can be an exclusion criterion, especially in the medical device sector. Devices that remain in the body for extended periods and, of course, implants are critical in this regard. Furthermore, these additives can burn or evaporate completely or partially when the metal powder is melted during the additive process. This can lead to defects, cavities, or shrinkage holes in the material structure of the component. There is a risk of deterioration in the mechanical, chemical, and electrical properties of the components.These risks are particularly high when manufacturing small components with thin walls in the micrometer range—as is the case with micro laser sintering. A defect of 3 micrometers, for example, represents a 3 percent weakening of a 100 micrometer thick wall, making it significant.

[0016] A disadvantage of the current processes and devices is that the reliable and uniform application of the powder is sometimes not guaranteed due to the very small particle size, which negatively affects the quality of the components.

[0017] The invention is therefore based on the object of providing microparts and microcomponents that exhibit improved quality compared to the prior art, particularly when using an agglomerating powder with a small particle size. This object is achieved by the features of independent patent claim 1 and by the features of independent patent claim 10. Further expedient embodiments of the invention are the subject of the dependent patent claims.

[0018] This object is achieved by a method and a device for producing micro-parts and micro-components by additive manufacturing using micro laser sintering, wherein a powdery agglomerating material (hereinafter referred to as powdery material) is applied layer by layer from a first powder reservoir and, after application, is melted by means of a laser beam, wherein, according to the invention, the powdery material located in the first powder reservoir is subjected to a force, wherein the force acts both when filling the first powder reservoir and when moving over a base plate and when applying to the substrate.

[0019] The force applied to the powdered material can be provided, for example, mechanically by means of spring force and / or by electric motor and / or by means of pneumatics and / or hydraulics.

[0020] The method comprises in particular the following steps: a. compacting the powdered material in a first powder reservoir open in the direction of a processing plane by exerting axial pressure on the powdered material in the direction of the substrate; b. applying and forming a first powder layer of the powdered material on an upper side of a substrate by moving the first powder reservoir parallel to the upper side of the substrate while simultaneously exerting force on the powdered material in the direction of the upper side of the substrate; c. selectively melting the first powder layer using a laser beam; d. lowering the substrate and e.Application of the compacted powdered material from the first powder reservoir while simultaneously exerting force on the powdered material on the first selectively melted powder layer or on further already formed and selectively melted powder layers and formation of further powder layers which are selectively melted until the micro-part or micro-component is completed, wherein the substrate is lowered before each further powder layer is applied.

[0021] It can further be provided that the powdered material is stored in a second powder reservoir, from which it is conveyed and / or pressed into the first powder reservoir. Preferably, the powdered material is pre-compacted in the second powder reservoir, and is then further compacted in the first powder reservoir if necessary.

[0022] From the second powder reservoir, the agglomerating material is preferably pressed into the first powder reservoir by a motor using a second force of 30N to 50N.

[0023] The force applied during application ensures that agglomerating powder is applied evenly and adheres reliably to the substrate.

[0024] During the entire application process, a first force always acts, particularly vertically downwards, in the direction of the substrate and the base plate.

[0025] This first force is constant.

[0026] The constant first force acts when moving over the base plate and the substrate and preferably also when filling the first reservoir.

[0027] The first force is intended to ensure that the agglomerating material behaves like a fluid, particularly when applied to the substrate and the further layers already melted and solidified above the substrate.

[0028] The anti-agglomeration agents previously used in the state of the art are no longer required with the solution according to the invention.

[0029] The initial force acting in this process is between 5 N and 50 N, particularly in the process range. Tests have shown that at this force the agglomerating powder, which has a maximum particle size of 20 p.m, behaves like a fluid, ensuring that it is applied more evenly.

[0030] During compaction of the powdered material in the first powder reservoir, a counterforce is preferably applied simultaneously with the compaction force to ensure uniform compaction. The counterforce can be provided, for example, by a horizontal base plate over which the first powder reservoir is moved before the first powder layer is applied.

[0031] Preferably, the substrate is lowered according to the required layer thickness of the next powder layer to be produced.

[0032] As an alternative to lowering the substrate, the processing plane and the first powder reservoir, as well as possibly other components that are present for carrying out the process, can be raised in such a way that their distance from a stationary substrate increases in accordance with the required layer thickness of the next powder layer to be produced.

[0033] Preferably, after the completion of the micro-component or micro-part, the micro-component or micro-part is separated from the substrate. The separation is preferably carried out by wire EDM. To reuse the substrate for a further implementation of the method according to the invention, any component residues remaining on the substrate after wire EDM are ground off, and the substrate surface is structured.

[0034] Advantageously, the substrate is structured prior to application of the powdered material such that the structure of the substrate surface is substantially adapted to the particle size of the powdered material. The structure may include depressions whose size corresponds to 0.5 to eight times the particle size of the powdered material. Advantageously, the individual particles of the powdered material remain in the depressions, thereby ensuring adhesion of the powdered material to the substrate surface.

[0035] Preferably, an infrared fiber laser is used to melt the first and / or subsequent powder layers. Laser sintering can be performed under a protective gas, which can be argon, for example.

[0036] A metallic material is preferred as the powdered material. Alternatively, a ceramic powder can be used.

[0037] It is also possible to process various metallic powders and / or ceramic powders.

[0038] In particular, stainless steel and / or titanium are used as powdered materials.

[0039] Preferably, the particle size of the agglomerating powdered material is a maximum of 20 pm

[0040] The object is further achieved by a device for carrying out the method according to the invention, comprising a horizontally oriented processing plane and a first powder reservoir arranged above the processing plane and horizontally movable on the processing plane, said first powder reservoir having an interior space for receiving a powdered material. According to the invention, the first powder reservoir is open in the direction of the processing plane, and the first powder reservoir has in its interior a means for generating an axial force acting in the direction of the processing plane on the powdered material located in the interior space, by means of which the agglomerating material 1 behaves like a fluid, at least during application in the process area 100.

[0041] The means for generating the axial force is preferably a piston whose dimensions completely or almost completely cover the cross-section of the interior of the first powder reservoir. The force transmitted to the powdered material by the means for generating the axial force can be provided mechanically by means of a spring and / or electrically and / or pneumatically and / or hydraulically.

[0042] It can be provided that the first powder reservoir has a measuring device in its interior with which the amount of powdered material present in the first powder reservoir can be determined. In particular, the device has a substrate arranged below the processing plane for receiving a first powder layer.

[0043] The substrate preferably has a substrate surface that, for example, acts like the surface of the agglomerating powdered material. This preferably results in forces acting between the substrate surface and the powdered material, so that the applied powdered material remains fully in contact with the substrate surface.

[0044] The structure of the substrate surface can be provided with depressions whose size corresponds to 0.5 to eight times the particle size of the powdered material. Advantageously, the individual particles of the powdered material remain in the depressions of the substrate surface, thereby ensuring that the powdered material adheres reliably to the substrate surface as the first layer.

[0045] In a preferred embodiment, the device according to the invention further comprises a second powder reservoir arranged below the processing plane with an interior space for receiving a powdery material, wherein the second powder reservoir is open in the direction of the processing plane and wherein the second powder reservoir has in its interior space second means for generating an axial force acting in the direction of the processing plane on the powdery material located in the interior space and is provided to fill the first powder reservoir.

[0046] The second means for generating the axial force in the second powder reservoir can also be a piston whose dimensions completely or almost completely cover the cross-section of the interior of the second powder reservoir. The force transmitted to the powdered material by the second means for generating the axial force can be provided mechanically by means of a spring and / or electrically and / or pneumatically and / or hydraulically.

[0047] The second powder reservoir is preferably designed in the form of a cartridge prefilled with powder, the lower base of which is motor-driven and displaceable toward the first powder reservoir using the second force. While the first powder reservoir is moved horizontally across the base plate, the base plate exerts a counterforce to the axial force exerted by the means(s) arranged in the first powder reservoir for generating the axial force.

[0048] Advantageously, the base plate is at least partially interrupted in a process area above the substrate. The interruption of the base plate above the substrate allows the powdered material to be applied from the first powder reservoir to the substrate surface.

[0049] It can further be provided that the base plate is at least partially interrupted in a filling area above the second powder reservoir. The interruption in a filling area makes it possible for the powdered material to be pressed from the second powder reservoir located below the filling area into the first powder reservoir located above the filling area. For this purpose, the first and second powder reservoirs preferably have the same opening area, via which the respective interior of the first and second powder reservoirs is open toward the interruption in the base plate in the filling area.

[0050] The device preferably comprises a laser for melting the first powder layer and / or additional powder layers. It can also be provided that the surface of the substrate is structured using the laser. The laser is preferably an infrared fiber laser. The laser beam is deflected in a known manner via one or more mirrors.

[0051] The invention advantageously utilizes the powder's inherent forces, which are also responsible for the generally undesirable agglomeration / clumping. In particular, by applying energy to the powdered material, the otherwise disruptive powder-inherent forces are overcome.

[0052] The invention is explained in more detail below with reference to exemplary embodiments and associated figures, without being limited to these.

[0053] They show:

[0054] Figure 1 shows the process steps of micro laser sintering according to the state of the art, Figure 2 shows a schematic representation of the filling process of the first powder reservoir,

[0055] Figure 3 Application of the first powder layer using the first reservoir,

[0056] Figure 4 Melting the required areas of the first layer using a laser beam,

[0057] Figure 5 shows the application of a further layer of powder with the substrate lowered, Figure 6 shows a device for unidirectional application of the powder with a one-sided recess in the base plate,

[0058] Figure 7 shows a device for bidirectional application of the powder with recesses on both sides to the substrate in the base plate,

[0059] Figure 8 shows a device for bidirectional application of the powder with barriers on two strips in a recess of the base plate and on both sides of the substrate,

[0060] Figure 9 shows a device for bidirectional application of the powder with barriers on two strips on the top side of the base plate and on both sides of the substrate.

[0061] Figure 10 inclined first powder reservoir.

[0062] Figure 1 shows the process steps for producing a component according to the prior art. A three-dimensional CAD model M of the product was created, from which a component is then produced by additive manufacturing using micro laser sintering. For this purpose, a powder reservoir 2' containing fine-grained powdered material T moves, as shown in illustration A, in a first step over the surface of a substrate 3' to which a thin layer of powder adheres. Subsequently, as shown in step B, the powdered material T on the substrate is melted by a laser beam 4' at the positions where it is to solidify. In step C, the substrate 3' is lowered by the amount of the next layer thickness to be produced.A further layer of material T is applied to the first layer using the powder reservoir 2', which moves horizontally over the already solidified layer. This layer is then also melted and solidified using the laser beam 4' (not shown). The substrate 3' is then lowered again (Figure D) and coated again with the powdered material T, and so on, until component B is completed according to the CAD model M as shown in Figure E by micro laser sintering using the laser beam 4'. Any unmelted powder is removed. Figure F shows the finished component B, which has been detached from the substrate.

[0063] A disadvantage of the prior art is that the powder does not adhere to the entire surface during application, which can lead to defects. Figure 2 shows a schematic representation of a first step of the method according to the invention, carried out on a device according to the invention.

[0064] The device comprises a base plate 5 with a top side 5a, a first powder reservoir 2 arranged above the top side 5a, and a second powder reservoir 7 arranged below the top side 5a. In Figure 2, both the first powder reservoir 2 and the second powder reservoir 7, which is preferably provided as a prefilled cartridge, are located in a filling area 200 of the device, in which the base plate 5 has an undesignated interruption.

[0065] In the first powder reservoir 2 there is a first means 6 for generating an axial force F1, by means of which the powdery material 1 in the interior of the first powder reservoir 2 is subjected to an axial force F1 in the direction of the base plate 5.

[0066] Located in the interior of the second powder reservoir 7 is a powdered material 1, which is subjected to a second axial force F2 acting in the direction of the first powder reservoir 2 by a second means 8 for generating it, indicated by an arrow in the figures. In the illustrated embodiment, the second means 8 for generating a second axial force F2 is a piston, which, for example, can also simultaneously be the base of the cartridge (which forms the second reservoir 7), which is axially adjustable within the peripheral wall (not designated) in the direction of the first reservoir 2.

[0067] The powdered material 1 is thus conveyed from the second reservoir 7 into the interior of the first powder reservoir 2 and compressed therein.

[0068] Since both the first powder reservoir 2 and the second powder reservoir 7 are open towards the base plate 5 in the filling area 200, the powdered material 1 is pressed into the interior of the first powder reservoir 2 when F2 is greater than F1.

[0069] Once the first powder reservoir 2 is filled, the first powder reservoir 2 is moved horizontally over the base plate 5 toward a process area 100 of the device, indicated by a dashed arrow. In the process area 100, the base plate 5 is interrupted above a substrate 3. The substrate 3 has an upper side 3a. A scanner with deflection mirrors 4.2 for deflecting a laser beam 4 of the laser 4.1, indicated by a dashed line, is arranged above the substrate; the laser 4.1 is not yet operating here. When moving over the base plate 5 and the substrate 3, a constant force F1 acts on the agglomerating material 1 located in the first reservoir 1.

[0070] Figure 3 shows schematically the step of the method according to the invention when applying a first powder layer S1 to the upper side of the substrate 3a in which the first powder reservoir 2 is moved over the upper side 5a of the base plate 5 and the upper side 3a of the substrate 3, here in the direction of the arrow to the right.

[0071] The first powder reservoir 2 moves over the substrate 3, whose upper side 3a lies slightly below the upper side 5a of the base plate 5, preferably exactly the layer thickness of the first powder layer S1 to be produced or in the order of magnitude of the layer thickness to be produced. With further downward axial force applied by the piston 6 to the powdered agglomerating material 1, the material is applied to the upper side of the substrate 3 with the force F1, whereby the agglomerating material 1 behaves like a fluid.

[0072] A first powder layer S1 of the material 1 remains on the upper side 3a of the substrate 3. The upper side 1a of the first powder layer S1 forms the processing plane for the selective melting of the first powder layer S1 by means of the laser beam 4 indicated here, after the substrate 3 has been completely coated with the first powder layer S1.

[0073] After application, the upper side 1 a of the first powder layer S1 lies in particular slightly above the upper side 5a of the base plate 5 and is preferably 20 to 200 pm higher than the upper side 5a of the base plate 5.

[0074] The substrate upper side 3a preferably has a surface quality that ensures that the first powder layer S1 of the powdered material 1 remains in place over its entire surface.

[0075] The laser 4.1 and the deflection mirror 4.2 of the scanner are arranged above the substrate 3.

[0076] After the first powder reservoir 2 has been moved completely over the substrate 3, the first powder layer S1 applied to the substrate 3 from the powdered material 1 is selectively melted by means of the laser beam 4 of the laser 4.1 and its deflection by means of the scanner 4.2 at the positions that are to be solidified, whereby after cooling, a solid laser-sintered metal layer 1.1 is formed at least in some areas (see Figure 4).

[0077] The substrate 3 is then lowered according to the required layer thickness of the next powder layer to be created (see Figure 5), and a further powder layer, here a second powder layer S2 made of the powdered material 1, is applied to the first layer S1 by an axial movement (dashed arrow) of the first powder reservoir 2, whereby the force F1 also acts. The upper side 2a of the second powder layer S2 now forms the new processing plane. The second layer S2 is then partially melted, so that a solid laser-sintered metal layer is formed, at least in some areas.

[0078] During the horizontal movement of the first powder reservoir 2 over the base plate 5, the powdered material 1 located in the first powder reservoir 2 is preferably further compressed by the first means 6 for generating an axial force F1 and subjected to the constant force F1 in the direction of the base plate 5 and the substrate 3 or the applied laser-sintered layer. The base plate 5 is preferably designed such that no or almost no powdered material 1 remains on the base plate 5 while the first powder reservoir 2 moves over it.

[0079] Laser 4.1 is preferably a fiber laser. For example, an infrared laser or a laser with a different wavelength is used. If necessary, the use of a different energy source is also possible, such as electron beams or beams emitted by LEDs.

[0080] Figure 6 shows a variant of the device according to the invention, in which the base plate 5 has a recess 5.1 next to the substrate 3 in the application direction (arrow direction), through which a barrier B is formed. This prevents the powder from being applied further onto the upper side 5a of the base plate 5.

[0081] The upper side 1a of the first layer S1, which is applied to the upper side 3a of the substrate 3, also forms the processing plane above the substrate 3.

[0082] The top side 1a is also preferably located 20 pm to 200 pm above the top side 5a of the substrate 3.

[0083] In the variant shown in Figure 6, the powder in the form of the agglomerating material 1 is applied unidirectionally in the direction of the arrow, with the first force F1 acting. Laser sintering is then performed, and the next powder layer is applied in the direction of the arrow. The return movement of the first powder reservoir 2 occurs in the opposite direction to the arrow before or after laser sintering. During the return movement, no powder layer is applied in the unidirectional mode.

[0084] In a further variant, the powder 1 is applied and then partially melted as the powder reservoir 2 moves back and forth in each direction. The powder 1 is thus applied in a first direction and partially melted, and then applied in the other direction and subsequently partially melted. In this bidirectional application, in which the first force F1 always acts on the agglomerating material 1, the doctor blades 9 located on the underside of the reservoir preferably have the same height at their lower edges 9.1 (see Figures 7-9). The substrate 3 is lowered before each powder layer is applied.

[0085] In these bidirectional orders, a barrier B can be provided in each order direction.

[0086] Figure 7 shows a variant for bidirectional application, in which a depression 5.1 is also present in the base plate 5, which here extends on both sides of the substrate 3, whereby a barrier B in the form of a shoulder is formed in both directions of movement of the first reservoir 2.

[0087] According to Figure 8, a barrier B is formed by strips L arranged in the recess 5.1 of the base plate 5 on both sides of the substrate 3 and transverse to the direction of movement of the first powder reservoir 2. The sides of the strips L facing toward the second powder reservoir 2 form the barrier B.

[0088] Figure 9 shows an embodiment variant in which the base plate 5 has no recess, wherein the strips L on the upper side 5a of the base plate 5 are also positioned on both sides of the substrate 3 and, with their sides facing the second powder reservoir 2, also form a barrier B for the powder layer of powder 1 to be applied.

[0089] In the three aforementioned variants, the powder 1 is applied bidirectionally by means of the first reservoir 2, i.e., alternately back and forth in the direction of the dashed arrows. When using, for example, strips L with barrier B as shown in Figures 8 and 9, it is possible to arrange the strips L so that they can be adjusted toward and away from the substrate 3, as indicated by the arrows. This variable arrangement of the barrier(s) B makes it possible to adapt the distance of the barrier B from the substrate 3 to the coating properties of the powder 1 or the agglomerating properties of the powder 1.

[0090] According to variants not shown, the use of the portable barrier can also be applied for unidirectional application as shown in Figure 6.

[0091] In the variant shown in Figure 10, the powdered material is applied in one direction at a greater height and then removed in the opposite direction to the desired height h. The powdered material 1 is applied unidirectionally, from left to right, and removed from right to left.

[0092] For this purpose, the powder reservoir 2 has a first doctor blade 9 with a lower edge 9.1 in the application direction and, opposite thereto in a withdrawal direction (arrow direction), a second doctor blade 10 with a lower edge 10.1, wherein the lower edge 9.1 of the first doctor blade 9 has a smaller distance to the upper side 5a of the base plate 5 than the lower edge 10.1 of the second doctor blade 10.

[0093] When moving over the substrate 3 in the application direction - here to the right, a higher first layer S1 with a higher top side 1a' is applied to the substrate 3, corresponding to the height of the second squeegee 10. During the subsequent removal in the opposite direction - here to the left, the powder is removed to the height of the processing plane 1a by means of the first squeegee 9 and then melted.

[0094] The adjustment of the different heights of the doctor blades 9, 10 can be realized, for example, by an inclination of the powder reservoir 2 by an angle a between a longitudinal axis A of the reservoir 2 and the upper side 5a of the base plate 5 in the application direction.

[0095] When the first reservoir 2 is moved back in the withdrawal direction, the excess powder is leveled / removed to the correct height h by means of the first doctor blade 9.

[0096] Subsequently, the melting of the powder 1 can take place in the processing plane of the upper side 1a of the first layer S1 located above the substrate 3. The height H of the applied powder 1 is approximately 2 to 10 times the height h of the removed layer S1... S2, etc., in the unidirectional application described above in relation to Figure 10.

[0097] The layer thickness of the respective equalized layer S1, S2... etc. before laser processing is preferably one to four times the particle size of the powder 1.

[0098] After completion of the micro-part or micro-component, the micro-part or micro-component is separated from the substrate 3, for example by wire erosion.

[0099] The substrate is preferably made of a metallic material, e.g., stainless steel, titanium, or ceramic. After separating a component from the substrate, the substrate surface can be processed so that it can be reused as a substrate in a subsequent process for manufacturing microcomponents. For this purpose, the surface is ground, for example, and then structured, for example, using a laser.

[0100] List of reference symbols

[0101] Reference numerals for Figure 1 - State of the art

[0102] T powdered material

[0103] 2' powder reservoir

[0104] 3' substrate

[0105] 4' laser beam

[0106] B component

[0107] M three-dimensional CAD model

[0108] Reference numerals for Figures 2 to 7

[0109] 1 powdered material

[0110] 1a Top side of the first powder layer S1 / processing plane 1a' Top side of the layer S1 applied in the application direction

[0111] 1.1 solid laser-sintered metal layer

[0112] 2 first powder reservoir

[0113] 2a Top side of the second powder layer S2 / processing level

[0114] 3 Substrat

[0115] 3a Top of the substrate

[0116] 4 laser beam

[0117] 4.1 Laser

[0118] 4.2 Scanner deflection mirror

[0119] 5 Base plate

[0120] 5.1 Deepening

[0121] 5a Top of the base plate

[0122] 6 first means for generating an axial force

[0123] 7 second powder reservoir

[0124] 8 second means for generating an axial force

[0125] 9 first squeegee

[0126] 9.1 Lower edge of the first squeegee

[0127] 10 second squeegees

[0128] 10.1 Lower edge of the second squeegee

[0129] 100 Process area 200 Filling area B Barrier F1 first axial force F2 second axial force L Bar

[0130] S1 first layer S2 second layer α inclination angle

Claims

AMENDED CLAIMS received by the International Bureau on 6 June 2024 (06.06.2024) 1. A method for producing micro-parts and micro-components by additive manufacturing using micro laser sintering, wherein a powdered agglomerating material (1) is applied layer by layer from a first powder reservoir (2) and melted after application by means of a laser beam (4), characterized in that the material (1) located in the first powder reservoir (2) open in the direction of a processing plane is agglomerating powder whose particle size (1) is a maximum of 20 pm and that the agglomerating material (1) is subjected to a constant first force (F1) during an entire application process in the direction of a substrate (3), a process area and a base plate (5), by means of which force the agglomerating material (1) behaves like a fluid during application, wherein the force (F1) is 5 N to 50 N at least during the application process of the agglomerating material (1).

2. Method according to claim 1, characterized in that the force (F1) acts both during filling of the first powder reservoir (2) and when moving over a base plate (5) and the substrate (3) in the process area (100), wherein the first powder reservoir (2) is filled from a second powder reservoir (7) arranged below the processing plane and open towards the processing plane in a filling area (200), wherein in the second powder reservoir (7) an axial second force (F2) acting in the direction of the processing plane acts on the powdery material (1) located in the interior, and by an interruption of the base plate (5) in the filling area (200), the powdery material (1) is drawn from the second powder reservoir (7) arranged below the filling area (200) into the first powder reservoir located above the filling area (200). (2) is pressed,if the second force (F2) in the second powder reservoir (7) is greater than the first force (F1) in the first powder reservoir (2)., 3. Method according to claim 1 or 2, comprising the steps of: a. Compacting the powdered material (1) in a first powder reservoir (2) open in the direction of a processing plane by exerting axial pressure with the first force (F1) on the powdered agglomerating material (1) in the direction of the substrate (3) in the process area (100), b. Applying and forming a first powder layer of the powdered agglomerating material (1) onto the structured upper side (3a) of the substrate (3) by moving the first powder reservoir (2) parallel to the upper side of the substrate (3a) while simultaneously exerting force on the powdered agglomerating material (1) in the direction of the upper side (3a) of the substrate (3); c. Selectively melting the first powder layer (S1) using a laser beam (4); d. Lowering the substrate (3), and e.Application of the compacted powdery agglomerating material (1) from the first powder reservoir (2) with simultaneous exertion of force on the powdery material (1) on the first selectively melted powder layer or on further already formed and selectively melted powder layers and formation of further powder layers which are selectively melted until the micro-part or the micro-component is completed, wherein before the application of each further powder layer the substrate (3) is lowered.

4. Method according to one of claims 1 to 3, characterized in that the first powder reservoir (2) is moved horizontally over a base plate (5) and the substrate (3) after being filled with the powdered agglomerating material (1) and compacting the powdered material (1), wherein the constant first force (F1) acts.

5. Method according to one of claims 1 to 4, wherein after the completion of the micro-component, the micro-component is separated from the substrate (3), wherein the separation is preferably carried out by means of wire erosion.

6. Method according to one of claims 1 to 5, wherein an infrared fiber laser is used to melt the first and / or further powder layers of the agglomerating material (1). "I. Method according to one of claims 1 to 6, wherein a metallic or ceramic material is used as the powdery agglomerating material (1). 8.Device for carrying out a method according to one of claims 1 to 6, wherein the device has a horizontally oriented base plate (5) which is at least partially interrupted in a process area (100) above a substrate (3) and with a first powder reservoir (2) arranged horizontally displaceably above the base plate (5) and above the base plate (5) and having an interior space for receiving a powdery agglomerating material (1), characterized in that the first powder reservoir (2) is open in the direction of the base plate (5) and a substrate (3) arranged within the base plate (5), and wherein the first powder reservoir (2) has in its interior space first means (6) for generating a constant axial first force (F1) acting in the direction of the base plate (5) and the substrate (3) on the powdery agglomerating material (1) located in the interior space with a particle size of maximum 20 p.m, by means of which the agglomerating material (1) behaves like a fluid at least in the process area (100), wherein the first force (F1) is 5 N to 50 N.

9. Device according to claim 8, characterized in that the first powder reservoir (2) has in its interior first means (6) for generating the axial force (F1) acting in the direction of the base plate (5) and the substrate (3) on the powdery agglomerating material (1) located in the interior, which also acts when filling the first powder reservoir (2) in a filling area (200), and in that the device has a second powder reservoir (7) with an interior for receiving a powdery agglomerating material (1), wherein the second powder reservoir (7) has second means (8) for generating a second force (F2) acting in the direction of the first powder reservoir (2) on the powdery material (1) located in the interior,wherein the base plate (5) has an interruption in the filling area (200) and both the first powder reservoir (2) and the second powder reservoir (7) are open towards the base plate (5), and the powdery agglomerating material (1) can be pressed from the second powder reservoir (7) arranged below the filling area (200) into the first powder reservoir (2) located above the filling area (200) when the second force (F2) in the second powder reservoir (7) is greater than the first force (F1) in the first powder reservoir (2).

10. Device according to claim 8 or 9, characterized in that the device has in the process area (100) a substrate (3) arranged below a processing plane with a structured upper side (3a) for receiving a first powder layer (S1), wherein the processing plane is formed by the upper side (1a) of the powdery material (1) applied in the area of ​​the substrate (3).

11. Device according to one of claims 8 to 10, characterized in that an upper side (3a) of the substrate (3) is structured such that the structure of the substrate surface is adapted to the particle size of the powdered agglomerating material (1), wherein the structuring has depressions whose size corresponds to 0.5 times to eight times the particle size of the powdered material.

12. Device according to one of claims 8 to 11, characterized in that it has a base plate (5) arranged below the processing plane.

13. Device according to one of claims 8 to 12, characterized in that the base plate (5) has a recess (5.1) next to the substrate (3) in the application direction, by means of which a barrier (5.2) is formed which prevents the powder from being pushed beyond it.

14. Device according to one of claims 8 to 13, characterized in that the first powder reservoir (2) has, in the case of bidirectional powder application transversely to the direction of movement, doctor blades (9) on both sides of / on the first powder reservoir (2), the lower edges (9.1) of which are at the same distance from the upper side (5a) of the base plate (5).

15. Device according to one of claims 8 to 14, characterized in that in a unidirectional powder application, the first powder reservoir (2) has a first doctor blade (9) in an application direction and a second doctor blade (10) in an opposite withdrawal direction, wherein the lower edge (9.1) of the first doctor blade (9) has a smaller distance to the upper side (5a) of the base plate (5) than the lower edge (10.1) of the second doctor blade 16. Device according to claims 8 to 15, characterized in that the second powder reservoir (7) is designed in the form of a cartridge pre-filled with powder, the base of which can be displaced by motor in the direction of the first powder reservoir with the second force (F2).

17. Device according to one of claims 8 to 16, further comprising a laser and scanner (4.1) for melting the first powder layer and / or further powder layers and for structuring the substrate (3).

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