DE102018112128A1 - Method for the generative production of a component, device for carrying out the method and motor vehicle - Google Patents

Abstract

The invention relates to a method for the generative production of at least one component, a device for carrying out the method and a motor vehicle, in particular a passenger car. In a method for the generative production of at least one component (12), a powder (20) of a material (22) is applied and at least partially melted and the molten material (22) solidifies for the purpose of at least partially forming the component (12). Applied powder (20) is compacted for the purpose of producing a powder composite, so that a proportion of gas or gas mixture contained in the powder composite is reduced in order to increase the mechanical strength of the powder composite.

Description

The invention relates to a method for the generative production of at least one component, a device for carrying out the method and a motor vehicle, in particular a passenger car.

Generative manufacturing processes, also referred to as additive manufacturing processes, have found their way into various areas of industrial production due to numerous advantages. In particular, the flexibility of these methods, which allow the production of components without molds and thus can be used without expensive or costly changes for the production of new or modified components, qualifies them for a wide range of applications.

In the case of the powder bed processes, a layered structure takes place in which a powder layer is applied and the individual powder particles are locally connected. This occurs during selective laser melting, for example by local melting by means of laser radiation. In binder jetting, on the other hand, the particles are bonded together by means of a binder and the component is produced in this way. This method has in common that a surface of a powder bed for the purpose of connecting the powder particles is processed in areas. The loose powder from unprocessed areas can be used to support the following powder layers to be joined and is typically removed after fabrication of the component. With such methods, components with overhangs of up to 15 ° can be produced.

In the previously known methods, following the joining of powder particles of a layer, the powder bed is lowered by one layer height and the application of another layer of loose powder.

The DE 10 2013 011 675 A1 describes a method for the generative component production, in which a powdery material is melted in layers by means of laser radiation. This is also called selective laser melting. The intensity of the laser radiation is spatially and / or temporally changeable within the processing plane. In a first range, the intensity is set such that the melting temperature of the material is reached or exceeded. In several outlying second areas each set a lower intensity. The intensities can be set independently of each other. In particular, a preheating of the material can be realized before melting.

The EP 3 034 205 A2 discloses an apparatus for generatively producing a component on a building surface with a coater for producing a powder layer and a laser for locally melting the powder layer. Furthermore, the device comprises a deflection device for deflecting the laser beam to different areas of the powder layer or for focusing the laser beam and a compensation device for aligning the construction surface and a focal surface of the laser beam to each other. This allows the correction of an adjusted during the manufacturing process focus position and thus serves to set the desired local energy density of the laser beam. For example, a measuring system may be arranged in the beam path of the laser to image the shape and size of the laser spot and to determine on the basis of whether the laser is focused. The deflector may include an F-theta lens to provide a planar focus area.

The DE 10 2015 103 127 A1 describes a laser-based irradiation system for a device for additive manufacturing with a first beam source and a second beam source. The irradiation system furthermore has a common scanner optics for focusing the two laser beams and a beam combiner for superimposing the two beams. Thus, split laser beams or different laser beams can be coupled into a single transport fiber and moved together by means of a scanner optics over a region of the powder layer to be melted. Radiation from an annular fiber sheath of a transport fiber having a larger focus diameter can heat the powder over a large area to a temperature near the melting point, and the laser beam from the fiber core of the transport fiber serves to melt the powder.

In other previously known 3-D printers for the production of metal components, several laser scanner units with respective laser sources divide the surface of a powder bed and are thus able to produce areas of components to be manufactured together or separate components. In this way, for example, calipers are produced. In this case, the speed can be increased significantly, since several laser scanner units can produce a component simultaneously. The disadvantage is that all scanners must have completed the production of their assigned area before a new layer of powder can be applied and the process begins again.

It is the object of the invention to provide a method and a device, by means of which the generative production at least one component is possible in a particularly simple and cost-effective manner.

The object is achieved by the method for the generative production of at least one component according to claim 1 and by the device for carrying out the method according to claim 7. Embodiments of the method are specified in the dependent claims 2-6, embodiments of the device are in the subclaims 8 and 9 specified. Furthermore, a motor vehicle, in particular a passenger car, according to claim 10 is provided.

A first aspect of the invention is a method for the generative production of at least one component, in which a powder of a material is applied and at least partially melted and the molten material solidifies for the purpose of at least partially forming the component. Applied powder is compressed to produce a powder composite, so that a proportion of the gas mixture or gas mixture contained in the powder composite is reduced in order to increase the mechanical strength of the powder composite.

For example, the heating can be realized by means of irradiation by laser radiation. In doing so, it heats the powder in the area so that it is at least partially melted. Laser radiation is directed to a surface of the powder to form a point of impact. Of course, the entry point is not a point in the mathematical sense, but rather a performance surface. In the process, the surface and possibly also powder underneath are heated or melted.

In particular, the method according to the invention describes a method for selective laser melting, typically abbreviated SLM, but the method according to the invention can also be implemented as 3D printing, also referred to as binder jetting. In addition to laser radiation a variety of known methods for heating the powder are possible, which can be selected according to the respective requirements.

A powder in the sense of the invention is a material in the form of solid particles. The particle size is typically ≤ 0.5 mm. However, it is also possible to use granular substances or substance mixtures with larger particles. In particular, metallic materials are used. However, the invention is not limited thereto since it is also possible to process thermal plastics or plastic-coated metal particles, as known from the binder jet process. The latter are sintered at higher temperatures in an oven, in particular following the layered construction of the component, in which the plastic for the mechanical connection of the individual powder grains is at least partially melted, to produce a metallic structure with a higher strength.

The powder is especially applied for the purpose of producing a powder bed. This is typically done on a receiving device for receiving a powder and / or on material which has previously been at least partially melted and in particular solidifies again.

After solidification of the previously melted powder located in the region, in particular a renewed application of powder takes place, so that the component is produced in layers in this manner.

Typically, powder or surface forming powder disposed in a layer is partially melted. This means that only areas of the layer are melted, so that only in the molten areas, the component is produced, and other areas of the layer are not melted and thus continue to exist as a powder. The at least partial melting of the powder possibly also means that individual particles of the material are only partially melted, in particular in the respective edge regions of the particles, so that there is no continuous liquid phase. In this way, a fusion of the individual particles to form a substantially solid layer is possible. In other words, individual particles can be completely melted, individual particles can be partially melted, for example in edge regions, and / or individual particles can not be melted or remain solid.

The proportion of the gas or gas mixture means its share of the total volume of the powder and can also be referred to as a void fraction. He means that gas or gas mixture which is present between the powder grains or outside the powder grains. This is at least partially removed by the compression, which causes a volume reduction of the powder.

In addition, the powder can be densified so that powder grains are deformed. In other words, the yield strength of at least some powder grains is at least partially exceeded, so that even without removal or after the removal of corresponding gas or gas mixture volume, a volume reduction of the powder takes place. For example, powder grains interlock or nestle against one another. In this way, the mechanical strength of the resulting powder composite is also increased.

In particular, a mechanical compression is meant, ie an introduction of force into the powder in order to minimize the proportion of the gas or gas mixture or for the purpose of compression of the powder.

A significant advantage of the method according to the invention is that the compaction of the powder makes it possible to produce components with projecting regions or overhangs of any angle without the need for supporting structures. The strength of the compacted and unfused powder composite is suitable for carrying molten material. The hitherto necessary support structures for these purposes have hitherto required a possibly complicated post-processing of manufactured components for the separation and removal of the support structures. In this context, the proper process can increase the speed of manufacturing components and the proportion of reusable powder. In addition, the powder composite is insensitive to vibration. The powder composite means the compacted powder.

Also, higher layer thicknesses are possible, which - with suitable geometry of the components to be produced - possibly bring about a further significant increase in speed and efficiency of production. This is partly due to the fact that the heat conduction in the compressed powder composite is better than in the non-compacted powder and thus, for example, by irradiation by laser radiation, a melting thicker layers of the powder composite is possible.

Another advantage of the method according to the invention is that a smaller volume shrinkage occurs during melting, since the proportion of gaseous substances between the powder grains is reduced. In this way, components with higher quality can be produced.

In one embodiment of the method, powder is applied to a third region of the powder or powder composite which is adjacent to a region melted for the purpose of forming the component, optionally compressed and at least partially melted, so that a projecting or overhanging region of the component to be produced only the compacted powder and thus without the use of a supporting element such as a support structure is formed. In other words, at any position, a portion of the component to be manufactured is formed such that it is supported only by compacted powder.

An embodiment of the method for the generative production of at least one component is characterized in that, for compacting, a compression element movable relative to the powder exerts a force on the region of the powder for compressing at least one region of the powder. In particular, the compression element introduces vibrations into the powder.

For example, the compacting element vibrates with respect to the powder and introduces it into the powder. Typically, the compacting member contacts the powder to apply the force and compress it. The compression element can thus be configured as a compression ram.

This embodiment has the advantage that the compaction of the powder is realized in a particularly simple, efficient and less error-prone manner.

A further embodiment of the method for the generative production of at least one component is characterized in that a substantially flat surface of the powder is produced prior to compacting, in particular by stripping off excess powder.

It can be a uniform, optionally flat, surface are prepared, for example by means of a doctor blade to ensure a uniform heating of the powder. A flat surface according to the invention means a surface running along a non-curved plane.

This embodiment has the advantage that defined layer thicknesses can be set in a particularly simple manner and thus a high dimensional accuracy of the manufactured components is achieved.

In one embodiment of the method for the generative production of at least one component, the volumetric fraction of the gas or gas mixture contained in the powder composite after compaction is less than 20% and in particular less than 10%.

As described, this means the volumetric fraction between gas or gas mixture located between the powder grains and the total volume of the powder or powder composite. For example, the volumetric proportion of the gas or gas mixture is about 5%. Without compression, for example, the proportion is about 30%.

It has been found that the proportion below 20% and in particular below 10% is advantageous because it allows using comparatively low energy for the compression of the powder, a particularly good mechanical strength of the resulting powder bed.

A further embodiment of the method is characterized in that a secondary region of the powder, which is adjacent to a part of the powder to be melted or melted for the purpose of forming the component, is heated. The heating minimizes dissipation of heat from the molten powder by reducing temperature differences between the molten powder and the minor portion of the powder.

By minimizing the temperature difference and the associated minimization of heat dissipation, the total temperature of the powder bed or of the component to be produced is increased. In other words, a heat accumulation is generated. This has the advantage of minimizing thermal distortion resulting from volume shrinkage of the solidifying or cooling material. The cooling is slowed down and evened out. As a result, the stresses arising in the component, in particular tensile stresses, as are known in conventional methods, minimized. In one embodiment of the method, thermal insulation of the powder takes place. In this way, cooling of the powder is slowed down and evened out.

A further embodiment of the method is characterized in that the powder is moved along a feed direction, wherein the application of the powder, the compacting of the powder and in particular the melting of the powder at least in time sections at the same time take place at different positions along the feed direction.

The movement takes place in particular relative to an application device for applying the powder to a receiving device for receiving a powder and / or material, which may be previously at least partially melted and in particular solidified again, to a compacting device for compacting the powder and / or at least one Melting device for heating the powder for the purpose of at least partially melting the powder, such as a laser source for emitting laser radiation.

Typically, the powder is moved linearly. It may for example be arranged on a conveyor belt to be moved by means of this. Of course, the powder can also be moved in time periods without irradiation.

In other words, a continuous process for the generative production of at least one component is provided. This advantageously allows a particularly fast and cost-effective production of components.

A further embodiment of the method is characterized in that melting of a first region of the powder of the material arranged in a first plane takes place. At least at certain times at the same time, a powder of a material in a second plane spaced from the first plane is applied to a previously at least partially molten and especially again solidified second region of the material arranged in the first plane, optionally compressed and at least partially melted. In this way, at the same time an education several levels of a component takes place.

In particular, the first and the second plane are aligned parallel to one another. Typically, the same material is applied in the second level as in the first level.

In other words, a plurality of parallel planes of at least one component are produced at least in sections at the same time. There is a continuous, step-shaped production of several layers of at least one component. In this way, an entire component or a plurality of components can be produced completely in a continuous process. Due to the spatial proximity of the effective ranges of the respective laser radiation, which is possibly accompanied in the continuous process with rapidly successive irradiations by the individual laser sources, thermal gradients between individual regions of the component to be produced and / or the powder bed are reduced, so that a slow and uniform cooling can take place, which minimizes thermal distortion so that components of higher quality can be produced in a particularly simple manner.

In one embodiment of the method, powder is applied, heated and at least partially melted at least in sections of time in at least ten levels, in particular at least fifty levels, and in one embodiment in at least one hundred levels.

In particular, a distance measured along an advancing direction of the powder between an occurrence point of the laser radiation on the first region of the powder and an occurrence point of the laser radiation on the powder applied to the second region is less than 10 cm, in particular less than 3 cm. This can be achieved by the high quality of the laser radiation which can be realized by means of the method according to the invention, that is to say by the high beam quality or beam quality and optionally by high-quality polygon mirrors and long focal lengths of the lenses used. In this way, an apparatus for carrying out the method can be produced by means of which components constructed from several hundred layers are produced on a comparatively small space or with a relatively short distance.

In particular, the powder is applied in a thickness of between 50 μm and 1 mm. In one embodiment, a layer thickness between 50 microns and 1 mm is produced.

In one embodiment, the solidified material of the second region of the first plane during the application of the powder in the second plane at a temperature between 500 ° C and 1500 ° C, in particular between 700 ° C and 1000 ° C. Compared to conventional methods for the generative production of at least one component in which each molten layer largely cools before applying a further powder layer, in the inventive method in this way caused by volume shrinkage thermal distortion and thus remaining in the component or in the Component registered tensile stresses minimized. In other words, a heat build-up comprising multiple printed layers is realized, allowing slow and even cooling.

A second aspect of the invention is an apparatus for carrying out the method according to the invention. This comprises an application device for applying a powder and a compacting device for compacting the powder applied in order to produce a powder composite with a reduced proportion of gas or gas mixture contained in the powder composite for increasing the mechanical strength of the powder composite. The apparatus further comprises at least one melting device, in particular a laser source, for at least partial melting of the compacted powder.

The application device is used in particular for applying the powder to a receiving and moving device or to previously at least partially melted and in particular again solidified material.

The melting device is in particular a laser source for realizing laser radiation on at least one region of the powder for heating the powder. However, it may alternatively or additionally comprise any known device for heating the powder, which can be selected according to the respective requirements.

The device according to the invention is simple and inexpensive and serves the particularly efficient generative production of components. It is suitable for carrying out the method according to the invention and therefore has the above-described advantages of producing arbitrarily cantilevered or overhanging molds without support structures, the higher possible layer thicknesses and the low volume shrinkage.

An embodiment of the device for carrying out the method is characterized in that the compression device comprises a movably arranged compacting element with a compacting surface for exerting a force on at least one region of the powder along a force-exerting direction for producing a compacted surface.

In particular, the compacting surface is flat, so that it is suitable for producing a powder composite with a flat surface. The compacting device may further comprise a compression drive for moving the compacting element relative to the powder for compacting the powder. This can be configured, for example, as a vibration drive in order to vibrate the compression element in relation to the powder. Thus, the compression element according to the principle of the vibrating plate act.

The compacting element can be designed, for example, as a stamp, which executes vibrations in relation to the powder and introduces these into the powder for compression.

In particular, the compression element is set up or arranged such that its lifting height is adjustable in order to be able to produce a defined layer thickness in this way.

In one embodiment, the compression surface extends along a compression plane and the compression element has an insertion surface which forms a common edge with the compression plane and for compacting powder to introduce the powder below the compression surface upon relative movement between the powder and the compression element perpendicular to the force application direction suitable is.

The insertion surface is in particular a flat surface which is arranged at an angle with respect to the compression surface and outside the compression surface. The insertion surface faces the compression plane and the powder to be compacted. In other words, in the described relative movement between the powder and the compression element, the insertion surface compacts the powder which has not yet been compacted and compresses the surface of the powder, so that it can be moved in a simple manner below the compression plane of the insertion surface. This can also be referred to as pre-compaction. In particular, the insertion surface is designed as an insertion bevel.

The insertion surface can be selected in terms of their length and their angle to the compression plane depending on the compression properties of the powder to be compacted. For example, moreover, the feed rate of the relative movement between the powder and the compression element perpendicular to the direction of force and the stroke frequency can be coordinated so that each area of the powder is arranged below the compression element during a defined number of strokes and thus each area is uniformly compressed.

This embodiment has the advantage that the device is suitable for particularly simple and less susceptible to damage compaction of the powder.

The apparatus may comprise means for producing a substantially planar surface of the powder, in particular a squeegee for scraping off excess powder.

In a further embodiment of the device, this comprises a receiving and moving device for receiving a powder and movement of the powder along a feed direction and a plurality of generative devices for the generative production of a respective material layer of at least one component. Each generation device comprises an application device for applying the powder for the purpose of arranging the powder on the receiving and moving device or on material which has previously been at least partially melted and in particular again solidified. Each generation device further comprises a compression device and a melting device.

In particular, the generation devices are arranged one behind the other along the feed direction of the powder.

In particular, each generation means serves to apply at least partial melting and solidification of a layer of powder so that a layer of the component is produced. The number of generation devices thus corresponds to the number of layers that can be produced. In one embodiment, the device has at least ten, in particular at least fifty, and in one embodiment at least one hundred generation devices, which are arranged one behind the other along the feed direction.

Each generation means may comprise means for producing a substantially planar surface of the powder.

A third aspect of the invention is a motor vehicle, in particular a passenger car. This comprises at least one component produced by the method according to the invention. In particular, it is a metal component.

The invention is explained below with reference to the exemplary embodiments illustrated in the accompanying drawings, which illustrate different aspects and embodiments.

• 1: eine schematische Darstellung einer Ausgestaltung einer Vorrichtung,
• 2: eine erste Ausgestaltung einer Leitungs- und Ausgabeeinrichtung zur Nutzung in einer Vorrichtung,
• 3: eine schematische Darstellung der Funktion der Leitungs- und Ausgabeeinrichtung aus 2,
• 4: eine zweite Ausgestaltung einer Leitungs- und Ausgabeeinrichtung zur Nutzung in einer Vorrichtung,
• 5: eine schematische Darstellung der Funktion der Leitungs- und Ausgabeeinrichtung aus 4,
• 6: eine erste Multispotanordnung von Leitungs- und Ausgabeeinrichtungen zur Nutzung in einer Vorrichtung,
• 7: eine schematische Darstellung der Nutzung der ersten Multispotanordnung aus 6,
• 8: eine schematische Darstellung der Nutzung von Leitungs- und Ausgabeeinrichtungen,
• 9: eine schematische Darstellung eines in der Vorrichtung nutzbaren Lichtleiters,
• 10: eine erste Multispotanordnung in der Vorrichtung nutzbarer Lichtleiter,
• 11: eine zweite Multispotanordnung in der Vorrichtung nutzbarer Lichtleiter,
• 12: eine dritte Multispotanordnung in der Vorrichtung nutzbarer Lichtleiter,
• 13: eine erste perspektivische Darstellung eines Details einer Vorrichtung,
• 14: eine zweite perspektivische Darstellung eines Details der in 13 gezeigten Vorrichtung, sowie
• 15: eine schematische Darstellung einer weiteren Ausgestaltung der Vorrichtung.

Show it

• 1 : a schematic representation of an embodiment of a device,
• 2 : a first embodiment of a line and output device for use in a device,
• 3 : a schematic representation of the function of the line and output device from 2 .
• 4 : a second embodiment of a line and output device for use in a device,
• 5 : a schematic representation of the function of the line and output device from 4 .
• 6 a first multi-spot arrangement of line and output devices for use in a device,
• 7 : a schematic representation of the use of the first multi-spot arrangement 6 .
• 8th : a schematic representation of the use of line and output devices,
• 9 : a schematic representation of a usable in the device light guide,
• 10 a first multi-spot arrangement in the device of usable optical fibers,
• 11 a second multi-spot arrangement in the device of usable optical fibers,
• 12 a third multi-spot arrangement in the device of usable optical fibers,
• 13 : a first perspective view of a detail of a device,
• 14 : a second perspective view of a detail of the 13 shown device, as well
• 15 : a schematic representation of a further embodiment of the device.

1 shows a part of an embodiment of a device for the generative production of at least one component. There will be respective laser radiation 30 from four laser sources 34 overlaid to an area 25 a arranged in a plane powder 20 of a material 22 or its surface 26 to irradiate and heat in this way and at least partially melt. After completion of the irradiation by means of the laser radiation 30 solidifies the molten material 22 for the at least regional formation of at least one component.

The illustrated laser unit 32 comprises four linear laser sources arranged one behind the other 34 where respective mirrors 135 are arranged such that the respective laser radiation 30 in the direction of the powder to be irradiated 20 is superimposed and thus the cumulative laser radiation 30 all laser sources 34 at the same time on the powder 20 incident. In this way, a plurality of smaller sized laser sources 34 be used in total to achieve a high radiation power. The superimposed laser radiation 30 is by means of optical elements 132 namely a mirror and a condenser lens, distracted and focused.

It is a line and output device 70 namely, a circular cross-section having optical fiber 72 represented by which the laser radiation 30 in sections to the material 22 is directed. At the end of the line and output device shown on the left 70 the laser radiation occurs for the purpose of deflection or focusing by means of the optical elements 132 from the line and output device 70 out. At the end shown on the right, the laser radiation occurs 30 all four laser sources 34 in the line and output device 70 on. Such a superposition of several laser sources 34 or their respective laser radiation 30 can be used with any of the light guides described below 72 or line and output device 70 be realized.

In the inner area 75 of the light guide 72 is an information regarding the temperature of the irradiated material 22 , namely a heat radiation 60 , in the opposite direction to the laser radiation 30 directed. This radiates from the laser radiation 30 irradiated surface 26 goes through the same optical elements 132 as well as the laser radiation and is by means of another mirror 137 to a detection device 62 directed. This serves to detect the heat radiation 60 for influencing the laser intensity.

For this purpose, both the detection device 62 as well as the laser sources 34 with a control and / or regulating device 140 connected, which a temperature evaluation device 142 and a laser source controller 144 includes. The detection device 62 stands for evaluation on the surface 26 prevailing temperature in control connection with the temperature evaluation device 142 , This gives corresponding signals to the laser source control 144 which is adapted to receive one or more laser sources based on the received signals 34 in terms of their respective laser intensity. In this way, too high or too low irradiation can be detected and compensated accordingly.

Furthermore, a signal of interference radiation 130 represented, which of a the irradiated area 25 the surface 26 adjacent area is radiated and also through the optical elements 133 , the light guide 72 and the mirror 137 is broken or distracted. However, it can be seen that the interfering radiation 130 not from the detector 62 is detected and thus has no influence on the laser intensity. In other words, only the temperature signal from the center of the point of occurrence hits the detection device 62 and is used to thus influence the laser intensity. Due to the suitable design of the optical elements 132 , the mirror 137 and the detection device 62 ensures that no interference 130 prevents such regulation of the laser intensity.

2 shows a line and output device 70 for conducting and outputting laser radiation with a light guide 72 for use in a device for the generative production of at least one component. The front, bottom left end face of the line and output device 70 or of the light guide 72 serves to output the laser radiation for the purpose of irradiating the powder. The inner area 75 of the light guide 72 , an optical fiber, is as a glass body 76 configured and serves to transmit the heat radiation emitted by the irradiated or irradiated material in the direction of a detection device of the device.

In an alternative embodiment, the inner area 75 of the light guide 72 hollow. This has the advantage over the design in glass that the heat radiation can be detected even in spectral regions in which glass is not able to conduct the heat radiation, since glass is no longer transparent in these areas.

In other words, the inner area 75 configured for conducting or transmitting heat radiation. The line and output device shown here 70 is also called dual-core fiber.

The light guide 72 serves the at least partially guide the laser radiation from a laser source to be irradiated material. This means that the distance traveled by the laser radiation from the laser source to the point of impact on the powder is not necessarily completely through the light guide 72 is realized. The light guide 72 and his inner realm 75 each have coaxially arranged circular cross sections. In this way, exactly that emitted from the irradiated region of the material heat radiation for the purpose of influencing the laser intensity can be passed to the detection device. The respective materials of the light guide 72 as well as its inner area 75 have different refractive indices. The inner area 75 of the light guide is bounded by a glass surface. An outer diameter D1 the line and output device 70 or of the light guide 72 is between 50 μm and 1000 μm. Especially for larger systems, it makes sense to have an outer diameter D1 in the range of 500 microns to 1000 microns to realize.

In this case, advantageously, a ratio of the diameter of the inner region 75 to the outer diameter D1 to realize which is between 0.3 and 0.9. In particular, it is desirable to have this ratio between 0.5 and 0.8. This has the advantage that the heat radiation to be measured reliably the detection device 62 can be supplied.

3 shows schematically the operation of the described line and output device 70 , In the upper part of the figure is a segment of the line and output device 70 shown, which is cut off to improve the clarity of the presentation. In the case of an arrangement in the device for the generative production of at least one component, the line and output device would be in the further course 70 to the light guide 72 a laser source and to the inner area 75 of the light guide 72 a detection device connected.

It can be seen that laser radiation 30 from the end of the line and output device 70 or of the light guide designed as an optical fiber 72 exit. The emerging laser radiation 30 is divergent and becomes an optical element 132 namely a first condenser lens 138 , focused to produce a parallel beam path. The laser radiation 30 goes through another optical element 132 namely, a second condenser lens 139 , and is focused. In the state shown here is the focus or focal point of the laser radiation 30 before or after the point of occurrence of the laser radiation 30 on a surface forming material 22 of the powder 20 so that the laser radiation 30 at the point of impact, ie at its surface on the surface, again as divergent laser radiation 30 is present. This serves to realize a smooth transition between a cold core and a hot edge of the laser radiation at the point of impact. Typically, an optical pickup device is for guiding the laser radiation 30 over the powder 20 in the parallel beam path between the optical elements shown 132 arranged.

The irradiated area 25 is located on the line and output device 70 facing side of the powder 20 , The material irradiated 22 or from the named area 25 radiated heat radiation 60 passes through in the opposite direction to the laser radiation 30 the optical elements 132 and enters in this way in the glass body 76 designed inner area 75 the line and output device 70 , There it will be forwarded for the purpose of registration.

As an alternative to the embodiment described here, the inner region of the light guide 72 be designed as a hollow or hollow core, so as from an inner wall of the light guide 72 , a glass surface, limited volume of air to conduct the heat radiation.

4 shows an alternative embodiment of the line and output device 70 in which the light guide 72 as a photonic crystal fiber 73 is designed. This optical fiber has fine channels or cavities aligned along its direction of the light guide which, as structures with a refractive index, influence the movement of laser radiation. In this way, laser radiation can be directed particularly efficiently. The inner area 75 of the light guide 72 is in this embodiment as a cavity 77 or hollow core designed. The line and output device 70 is surrounded by a glass jacket 78 , The diameter D2 of the inner area 75 of the light guide 72 is about 30 microns and the diameter D3 of the light guide 72 is about 100 microns.

5 shows the use of in 4 described line and output device 70 in a device for the generative production of at least one component. Analogous to the representation of the 3 this is cut off in its upper part. The laser radiation 30 occurs at the bottom of the light guide 72 and hits the area to be irradiated 25 of the powder 20 of the material 22 , From the area 25 radiated heat radiation 60 occurs in the opposite direction to the laser radiation 30 in the as cavity 77 designed inner area 75 the line and output device 70 and is guided by this in the direction of a detection device, not shown. It can be seen that a wall of the inner area 75 designed to reflect the heat radiation. This can in all described embodiments of the line and output device 70 be the case.

6 shows a square multi-spot arrangement 100 acting as a field or array with five by five line and output devices 70 is designed. In this case, the individual line and output devices 70 analogous to the 2 or 4 and thus be designed as a dual core fiber or as a hollow core having photonic crystal fiber. All piping and dispensing equipment 70 have a light guide 72 and its interior area configured to transmit the information 75 on, with the light guide 72 and the inner area 75 are arranged coaxially.

Such a multi-spot arrangement 100 On the one hand, it can be used for this purpose by means of the line and output devices arranged side by side along a first expansion direction 70 or the laser sources connected to them to irradiate a portion of the powder in succession, and thus to realize a heating and / or melting of the region in several steps. This can be realized by means of an optical scanning device during a movement of the powder along a feed direction and / or during a scanning of the surface with laser radiation output from the multi-spot arrangement. The output devices arranged next to one another along a second expansion device can be used to simultaneously irradiate a portion of the powder in order to cumulate the radiation powers of the laser sources connected to the respective output devices, or to sequentially multiply a portion of the powder during a scanning of the surface by means of a plurality of laser sources irradiate. Also, analogous to 1 several laser sources in the individual line and output devices 70 be coupled.

7 shows schematically and exemplarily the use of the multi-spot arrangement 100 out 6 in carrying out a method for the generative production of at least one component. A powder of a material 22 is used to make a component 12 by means of the light guides 72 irradiated laser radiation so that it is heated and at least partially melted. The molten material 22 solidifies after irradiation for at least partially forming the component 12 , Information regarding the temperature of the material to be irradiated or irradiated 22 , namely a heat radiation 60 , is in the inner area 75 the light guide 72 transferred for the purpose of their detection for influencing the laser intensity.

The measured by the respective heat radiation temperatures T1 to T6 the respective appearance points of the individual line and output devices 70 are in different hatching in the inner area 75 represented the respective light guide. The first temperature T1 corresponds to a temperature range between about 750 ° C and 899 ° C, the second temperature T2 corresponds to a range between about 900 ° C and 949 ° C, the third temperature T3 corresponds to a range between about 950 ° C and 1099 ° C, the fourth temperature T4 corresponds to a range between about 1100 ° C and 1299 ° C, the fifth temperature T5 corresponds to a range between about 1300 ° C and 1599 ° C and the sixth temperature T6 corresponds to a temperature of about 1600 ° C and possibly higher.

It can be seen that in the appearance of the line and output device shown above right 70 a comparatively low temperature T1 prevails because this point of occurrence on the one hand along the scan direction 31 the multi-spot arrangement 100 from lies and thus the material located there 22 not yet been irradiated. On the other hand, this point of occurrence is along the feed direction 49 of the material 22 behind and was not irradiated in a previously realized scan yet. The appearance point arranged underneath has a significantly higher third temperature T3 because it was irradiated immediately before by means of laser radiation, by means of the line and output device shown above right 70 was issued. The further points below show correspondingly higher temperatures.

The top left entry point already has a high fifth temperature T5 because he is in the immediate vicinity of hot, as previously irradiated material 22 is arranged. The entry points below show correspondingly even higher sixth temperatures T6 on. In the upper row, the temperature drops due to the dwindling influence of the already heated, previously irradiated material 22 left to right. Downwards, the respective temperatures increase as described. After reaching a defined maximum temperature, for example, the laser intensity can be reduced so that there is no area in which the material overheats 22 comes.

Schematically is a scanning direction 31 which shows a relative movement of the respective points of occurrence of the light guides 72 in relation to the surface to be irradiated. The material 22 becomes during the movement of the appearance points along the scanning direction 31 irradiated in succession by laser radiation of multiple laser sources, at the same time with the irradiation, the heat radiation of the respective irradiated areas directed to a respective detection device, detected by means of this and used to influence the laser intensity. In particular, the respective appearance points are guided over the surface by means of a rotating polygon mirror or else a pendulum movement of leading mirror. In particular, the embodiment with oscillating mirror represents a cost-effective variant in which the heating process is to be reversed.

A planar field optics can be used to uniformly irradiate the substantially planar surface of the powder.

In addition to guiding the points of occurrence over the surface, there is a linear movement of the powder along the direction of advance 49 , In this way, a continuous process is provided for generatively producing at least one component in which the powder is relative to the optical fibers 72 and to applicators for applying the powder is moved to realize in this way a continuous layer-by-layer production of the component.

The individual line and output devices 70 the multi-spot arrangement 100 out 7 are schematic in 8th shown here, whereby here in the respective inner area 75 the light guide 72 shown hatching the above temperature ranges of the first temperature T1 up to the sixth temperature T6 correspond.

The 9 to 12 show schematically different arrangements of optical fibers 72 of line and output devices analogous to 7 , These may, in some embodiments, alternatively to those in the 2 and 4 used line and output devices are used. In these embodiments, as a conduit and output devices for the conduction and output of laser radiation thus light guide 72 , For example, optical fibers used.

The in 9 shown light guide 72 has a diameter D4 of 500 μm -1000 μm. It can be used to output laser radiation of an arbitrarily arranged laser source such that it occurs at a desired position on the powder to be heated. The illustration shows a plan view of one end of the light guide 72 , which is adapted to output laser radiation and thus serves as an output device for outputting laser radiation. This also applies analogously to the following figures.

In 10 is a square multispot arrangement 100 represented as a field or array with five by five light guides 72 is designed. For preferred diameters of the individual line and output devices in the range of 500 microns, the length is L1 along both extension directions of the square arrangement corresponding to 2.5 mm. Such a multi-spot arrangement 100 can analogously to in the 6 and 7 shown multispot arrangement 100 be used.

Depending on the respective requirements, different arrangements of the individual optical fibers 72 within the multi-spot arrangement 100 be chosen so that, for example, rectangular or round shapes are present as the 11 and 12 are shown.

13 shows schematically a detail of a device for the generative production of a component 12 , A powder 20 of a material 22 is arranged on a recording and movement device, not shown here, and is through this along the feed direction 49 emotional. A laser unit 32 at sixteen in a fixed multi-spot arrangement 100 arranged line and output devices is above the powder 20 and arranged behind this. The line and output devices are connected at their respective other ends, each with a laser source, not shown here, which also part of the laser unit 32 is. The multispot arrangement 100 is designed as a field or array with two by eight line and output devices, so that each eight line and output devices at different positions along the feed direction 49 , namely one behind the other, are arranged and in each case two line and output devices at the same position along the feed direction 49 , side by side, are arranged. The illustration shows exemplary line and output devices according to the 2 respectively. 4 However, such can also be done after the 9 to 12 be used.

In this way, the laser sources connected to each of the eight line and output devices arranged one behind the other are arranged in such a way or configured by means of the respective line and output devices that they are used to output laser radiation at different positions along the feed direction 49 are set up. That way the area can 25 of the powder 20 on movement of the powder 20 along the feed direction 49 irradiated by each of the eight juxtaposed line and output devices output laser radiation successively. In this way, the heating or melting of the area takes place 25 in eight steps.

For further movement along the feed direction 49 , after the passage of the laser unit 32 , the molten material solidifies 22 for the purpose of at least partially forming at least one component. In this way, a material layer 27 educated.

The two adjacent line and output devices can, depending on the optical elements used on the one hand, the simultaneous irradiation of the respective Part of the powder 20 serve in this way the on the part of the powder 20 to increase overall realized radiant power. In addition or as an alternative, they can be used to irradiate a region in chronological succession 25 the surface 26 while guiding the respective laser radiation over the surface 26 along the scanning direction 31 serve. As an alternative to the arrangement of the line and output devices shown here, these could also be arranged in a zigzag offset order along the feed direction 49 to output laser radiation at different positions one behind the other. Each of the line and output devices shown can be analogous to 1 coupled to a plurality of laser sources and thus be set up for the conduction and output by means of a plurality of laser sources output laser radiation.

The device further comprises a rotating polygon mirror 38 whose rotation axis is parallel to the feed direction 49 runs. This serves to guide the punctually exiting from the respective line and output devices laser radiation over the surface 26 of the powder 20 which is also called scanning. In this case, a point of occurrence of the respective laser radiation moves along a direction perpendicular to the feed direction 49 extending scanning direction 31 ,

In addition, the device comprises a planar field optics 36 , namely an F-theta lens, by means of which a deflection of the laser radiation takes place, so that a uniform irradiation of the flat surface 26 of the powder 20 is feasible.

In 14 is a further detailed representation of the device for the generative production of at least one component shown. This in 13 The detail shown here is shown in the middle, wherein the means of Multispotanordnung 100 output laser radiation 30 is shown schematically. In each case, the first and the last along the scanning direction 31 on the powder 20 impinging entry point shown.

Again, the plan field optics 36 as well as the rotating polygon mirror 38 with its parallel to the feed direction 49 aligned axis of rotation 39 shown. He turns along the direction of rotation 37 ,

It can be seen that the device has several generation devices 55 for the generative production of each one material layer 27 includes. Each of the generation facilities 55 includes an applicator 52 for applying the powder 20 for the purpose of arranging the powder 20 on the receiving and moving device 50 or on previously at least partially melted and re-solidified material. Furthermore, each generation means includes 55 as a melting device, a laser unit 32 with eight laser sources for temporally successive irradiation of the area 25 of the powder.

The applicator 52 includes a powder tank 53 and a powder well extending downwardly therefrom in the direction of gravity 54 for guiding the powder to the receiving and moving device 50 or on previously at least partially melted and re-solidified material. The powder tray 54 has a continuously expanding along the direction of gravity cross-section, so that blockages of the powder to be delivered are prevented. The in relation to the feed direction 49 front wall of the powder tray 54 serves as a squeegee 90 for stripping off excess powder to produce a flat powder surface.

Along the feed direction 49 behind the applicator 52 is as part of every generation 55 a compacting device 80 for compacting the applied powder 20 arranged. This serves to reduce the proportion in the powder 20 contained gas or gas mixture, so that the mechanical strength of the powder composite is increased. In other words, in the compression between the powder grains located gas is displaced or passed outwards and in this way the total volume of the powder 20 decreases or increases its density.

The compacting device 80 comprises a movably arranged compression element 82 , also referred to as a punch, with a compression surface arranged on the underside 83 to apply a force to the powder 20 along the vertically downwardly directed force application direction 85 , In this way, by means of the compression element 82 a compacted surface of the powder 20 getting produced.

The compaction element 82 is adapted to, by means of a double arrow schematically illustrated vibrations 81 in relation to the powder 20 perform and bring in this. Thus, by repeated application of force by means of the compression surface 83 the compacted surface of the powder 20 getting produced.

The compaction area 83 extends along a horizontally aligned compression plane 84 , The compaction element 82 has an insertion surface 87 on that one edge with the compression plane 84 forms or an asymptotic transition of the insertion 87 and the compression area 83 result. This serves to compact the powder 20 for the purpose of introducing the powder 20 below the compaction area 83 in a relative movement between the powder 20 and the compression element 82 perpendicular to the direction of force application 85 , In other words, it is during a movement of the powder 20 along the feed direction 49 first on this impinging area of the compaction element 82 designed as a slope, which facilitates the insertion of the powder 20 below the compaction area 83 the powder 20 condensed for the first time. This slope extends, starting from the horizontal compression surface 83 , obliquely against the feed direction 49 up. This promotes the compression element 82 by the change between upward movement and downward movement in the vibration 81 Powder feed in the area of the powder shaft 54 so that it does not come to a clumping.

It can be seen that the generation device shown on the right side 55 is shown completely, while in the subsequent, shown on the left side of the generation device 55 for reasons of clarity, the laser unit 32 not shown.

The generation equipment shown on the right 55 is used to make one in a first level 41 arranged material layer 27 on the surface of the receiving and moving device 50 , ie the conveyor belt. The left of it shown generation facility 55 serves to produce a in a second level 42 arranged material layer on the surface of the previously prepared material layer 27 the first level 41 , The second level 42 runs parallel to the first level 41 at a distance to this, the thickness of the material layer 27 or the corresponding powder layer corresponds. It can be a host of other generation devices 55 follow to produce the component completely in a continuous process, layer by layer.

When carrying out the method for the generative production of at least one component, the irradiation takes place in the first level 41 arranged first area 46 of the powder 20 , At the same time, on a previously at least partially melted and again solidified, in the first level 41 arranged and left of the first area 46 illustrated second area 47 of the material 22 powder 20 in the second level 42 by means of the applicator 52 applied, by means of laser radiation 30 heated and at least partially melted. In this way, the formation of multiple levels takes place at the same time 41 . 42 of the component. In this case, the order and the heating of the powder of the first level done 41 and the second level 42 in spatial and temporal proximity to each other, so that a total of slow and uniform cooling of the manufactured component can take place.

15 shows a schematic representation of a device 10 to carry out the process with nine generation devices 55 for generative production of a respective material layer of the component to be produced 12 , Of course, usually much more generation facilities 55 arranged to be built up from a plurality of material layers components completely with the device 10 to be able to produce. After application of all material layers, the manufactured component 12 and the excess compacted powder around it 20 by means of the conveyor belt 51 to the left side of the device 10 transported where it is in the so-called unpacking station 120 taken from excess powder 20 is released. This is in the powder assembly shown schematically 122 collected to be returned to the process.

Every generation 55 includes an applicator 52 with a powder tray 54 , In the embodiment shown here are all powder shafts 54 with a common powder tank 53 connected, from which they with powder to be applied 20 be fed. The applicator shown on the right 52 the first generation facility 55 serves the order of the powder 20 on the recording and movement device 50 namely, the metallic conveyor belt 51 in order to manufacture in the first level 41 arranged material layer. The following applicators 52 serve the order of the powder on the respective previously prepared material layers for the purpose of producing the in the second level 42 , the third level 43 , the fourth level 44 , etc. arranged material layers. It can be seen that at the same time as the production of the first area 46 the one in the first level 41 arranged material layer through the first generation device 55 to a second area 47 previously by means of the first generation device 55 manufactured, in the first level 41 arranged material layer by means of the second applicator 52 Powder applied and by means of the second laser spot arrangement 100 is irradiated. Thus, the first generation device serves 55 the production of the first level 41 arranged material layer, the second generation device 55 is used to make the second level 42 arranged material layer, etc.

Along the feed direction 49 behind a respective applicator 52 there is one laser unit each 32 comprising a multi-spot arrangement 100 and to respective optical fibers 72 the multi-spot arrangement 100 connected, not shown here laser sources. The multispot arrangement 100 is for example analogous to that in 6 or in 8th shown designed and serves the purpose described therein by the respective triangular laser radiation 30 should be schematic be hinted that the respective laser radiation of the respective at the same positions along the feed direction 49 Overlay arranged light guide. The dashed lines and double arrows in the area of the laser beams shown on the right 30 indicate that by means of suitable optical elements at the same time as the movement of the powder along the feed direction 49 and with the guidance of the respective points of occurrence of the laser sources over the surface to be irradiated along a direction perpendicular to the feed direction by means of the rotating polygon mirror 38 a control or adjustment of the angle can be made in the area shown here in order to realize a scanning of the surface along parallel paths. In addition, parameters of the laser radiation 30 how, for example, respective appearance points can be adapted to the respective requirements by suitable configuration of optical elements. Schematically represented is also the rotating polygon mirror 38 with its axis of rotation 39 ,

Below the along the feed direction 49 moving top of the conveyor belt 51 a cooling device is arranged, in which cold water 110 is fed along a flow direction 115 against the feed direction 49 flows while being heated due to heat emitted the molten layers and then as hot water 112 is taken in the right area of the illustration. This serves to influence the temperature and in particular a uniform cooling of the component 12 , In this connection, it can be seen that the temperature of the component to be produced or of the multilayer arrangement is highest on the right-hand side and along the feed direction 49 becomes smaller.

Every generation 55 further comprises a compression device 80 for compacting the applied powder to reduce the content in the powder 20 contained gas or gas mixture to increase the mechanical strength of the powder 20 , In this embodiment, the entire powder tank 53 for the execution of vibrations 81 or designed for shaking to this by means of respective (not shown) compression elements 82 in the applied powder to produce in this way a compacted surface of the powder.

LIST OF REFERENCE NUMBERS

device 10 component 12 powder 20 material 22 Area 25 surface 26 material layer 27 laser radiation 30 scanning direction 31 laser unit 32 laser source 34 Flat field lens 36 direction of rotation 37 Rotating polygon mirror 38 axis of rotation 39 First floor 41 second level 42 Third level 43 Fourth level 44 First area 46 Second area 47 feed direction 49 Recording and movement device 50 conveyor belt 51 applicator 52 powder tank 53 coffee chute 54 generation facility 55 thermal radiation 60 detector 62 Line and output device 70 optical fiber 72 Photonic crystal fiber 73 Inner area 75 vitreous 76 cavity 77 glass cladding 78 compacting device 80 vibration 81 compression element 82 condensing surface 83 summarization level 84 Force application direction 85 lead-in 87 doctor 90 Multi-spot arrangement 100 cold water 110 hot water 112 flow direction 115 unpacking 120 powder collection 122 Radiated 130 Optical element 132 mirror 135 mirror 137 First condensing lens 138 Second collective lens 139 control device 140 Temperature evaluation device 142 Laser Source Control 144 diameter D1 diameter D2 diameter D3 diameter D4 length L1 First temperature T1 Second temperature T2 Third temperature T3 Fourth temperature T4 Fifth temperature T5 Sixth temperature T6

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102013011675 A1 [0005]
• EP 3034205 A2 [0006]
• DE 102015103127 A1 [0007]

Claims (10)

Method for the generative production of at least one component (12), in which a powder (20) of a material (22) is applied and at least partially melted and the molten material (22) solidifies for the purpose of at least partial formation of the component (12), characterized that applied powder (20) is compressed in order to produce a powder composite, so that a proportion of gas or gas mixture contained in the powder composite is reduced in order to increase the mechanical strength of the powder composite. Method for the generative production of at least one component (12) according to Claim 1 characterized in that for compacting, a compacting member (82) movable relative to the powder (20) exerts a force on the region (25) of the powder (20) for compressing at least a portion (25) of the powder (20), the compacting member (82) introduces in particular vibrations (81) into the powder (20). Method for the generative production of at least one component (12) according to one of the preceding claims, characterized in that a substantially flat surface (26) of the powder (20) is produced before compacting, in particular by stripping off excess powder (20). Method for the generative production of at least one component (12) according to one of the preceding claims, characterized in that a secondary region of the powder (20) which is adjacent to a part of the powder (20) to be melted or melted to form the component (12) , is heated to minimize dissipation of heat from the molten powder (20) by reducing temperature differences between the molten powder (20) and the minor portion of the powder (20). Method for the generative production of at least one component (12) according to one of the preceding claims, characterized in that the powder (20) is moved along a feed direction (49), the application of the powder (20), the compacting of the powder (20). and in particular the melting of the powder (20) takes place at different time intervals at different positions along the feed direction (49) at least in time. Method for the generative production of at least one component (12) according to one of the preceding claims, characterized in that at least in sections at the same time for melting a first region (46) of the powder (20) of the material (22) arranged in a first plane (41) a second region (47) of the material (22) arranged in the first plane (41), at least partially molten and in particular again solidified, a powder (20) of a material (22) in a second plane spaced apart from the first plane (41) ( 42) is applied, possibly compressed and at least partially melted, so that at the same time a training of several levels (41, 42) of a component (12). Device (10) for carrying out the method according to one of Claims 1 - 6 comprising an applicator (52) for applying a powder (20), a compacting device (80) for compacting the applied powder (20) to produce a powder composite with a reduced proportion of gas mixture contained in the powder composite to increase the mechanical strength of the powder composite and at least one melting device, in particular a laser source (34), for at least partial melting of the compacted powder (20). Device (10) for carrying out the method according to Claim 7 characterized in that the compacting means (80) comprises a moveably arranged compacting member (82) having a compacting surface (83) for applying a force to at least a portion (25) of the powder (20) along a force applying direction (85) to produce a compacted surface (26), wherein in particular the compression surface (83) extends along a compression plane (84) and the compression element (82) has an insertion surface (87) which forms a common edge with the compression plane (84) and for compaction of powder (84). 20) for introducing the powder (20) under the compression surface (83) at a relative movement between the powder (20) and the compression element (82) perpendicular to the force application direction (85) is suitable. Device (10) for carrying out the method according to one of Claims 7 - 8th , characterized in that the device (10) comprises a receiving and moving device (50) for receiving a powder (20) and movement of the powder (20) along a feed direction (49) and a plurality of generation means (55) for the generative production of a respective material layer (27) at least one component (12), wherein each generation device (55) has an application device (52) for applying the powder (20) for the purpose of arranging the powder (20) on the receiving and moving device (50) or at least previously partially melted and in particular re-solidified material (22), a compression device (80) and a melting device comprises. Motor vehicle, in particular passenger car, comprising at least one with the method according to one of Claims 1 - 6 manufactured component (12).

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