DE102021121593A1 - Method and manufacturing device for the additive manufacturing of a component from a powder material - Google Patents

Abstract

The invention relates to a method for additively manufacturing a component (3) from a powder material, the powder material being successively arranged powder material layer by powder material layer in a work area (11), powder material layers of the powder material each being locally selectively irradiated with at least one energy beam (7), to solidify the powder material locally in the work area (11) by means of the energy beam (7) and thus to produce the component (3) in layers, with a protective gas flow having a specific protective gas flow direction being generated over the work area (11), the at least an energy beam (7) is displaced in the powder material layers at least in regions in the form of vectors (18) oriented collinearly with one another along a scanning direction (AR) and arranged next to one another along a feed direction (VR), with a feed angle (α) that the feed direction (VR) with the S includes protective gas flow direction, is changed between the powder material layers, the feed angle (α) being selected in such a way that the feed angle (α) for a plurality of powder material layers lies in a predetermined useful angular range (21), in which the feed direction (VR) is aligned at least in components against the flow direction of the protective gas, with the feed direction (VR) at the same time including an angle with a normal of the flow direction of the protective gas which is greater than a predetermined feed limit angle, the feed angle (α) for a minority of the powder material layers in a predetermined blocking angle range (22) outside of the useful angle range (21).

Description

The invention relates to a method and a manufacturing device for the additive manufacturing of a component from a powder material.

In such a method, the powder material is successively arranged powder material layer by powder material layer in a working area. Powder material layers of the powder material are each locally selectively irradiated with at least one energy beam in order to selectively locally solidify the powder material in the work area by means of the energy beam and thus to produce the component in layers. A protective gas flow with a specific protective gas flow direction is generated over the working area. The at least one energy beam is displaced in the powder material layers at least in regions in the form of vectors which are oriented collinearly with one another along a scanning direction and are arranged next to one another along a feed direction. A feed angle, which the feed direction encloses with the protective gas flow direction, is selected in a predetermined useful angular range in order to prevent the energy beam from interacting with a pollutant cloud of, for example, dirt particles, smoke or smoke, which would otherwise enter the area due to the protective gas flow of the energy beam could be entered. In particular, the aim is to prevent the energy beam from being scattered and/or weakened in an unforeseeable manner by the pollutant cloud, which can reduce the quality of the component being produced. Furthermore, it should be avoided that the energy beam strikes a location in the powder material layer at which pollutants have settled that have been introduced from another location—in particular due to the protective gas flow. The useful angle range therefore excludes in particular those feed angles in which the corresponding disadvantages - hereinafter referred to as "pollutant problem" for short - could materialize at least with some probability. In particular, a predetermined blocking angle range for the feed angle is avoided. At the same time, however, it turned out that with a view to the quality of the resulting component, in particular its mechanical properties such as breaking strength, yield point and elongation at break, it is not favorable if the feed angle is the same for all powder material layers. Therefore, the feed angle, which the feed direction includes with the shielding gas flow direction, is changed between the layers of powder material. While a narrowly selected useful angle range is favorable in order to effectively avoid the disadvantages associated with possible interaction with pollutants, it has also been found that in particular the mechanical properties, in particular breaking strength, yield point and elongation at break, of the resulting component when the feed angle is selected a narrow useful angle range can be reduced, in particular the mechanical properties of the resulting component strongly depend on its orientation in the powder material and in particular within the individual powder material layers. This is disadvantageous precisely for reasons of reproducibility, since in general the orientation of the resulting component in the powder material should be freely selectable depending on other criteria such as the efficiency of the method, the number of components to be produced in the work area and, if necessary, other criteria.

The invention is therefore based on the object of creating a method and a manufacturing device for the additive manufacturing of a component from a powder material, the disadvantages mentioned being at least reduced and preferably not occurring.

The object is achieved by providing the present technical teaching, in particular the teaching of the independent claims and the embodiments disclosed in the dependent claims and the description.

The object is achieved in particular by creating a method for additively manufacturing a component from a powder material, in which the feed angle is selected in such a way that it lies in a predetermined useful angular range for a plurality of the powder material layers, in which the feed direction is at least partially opposite the protective gas flow direction is aligned, at the same time the feed direction with a normal of the protective gas flow direction encloses an angle which is greater than a predetermined feed limit angle, the feed angle for a minority of the powder material layers in a predetermined blocking angle range outside the useful Angular range is. In this way, it is advantageously possible to produce components with reproducible mechanical properties, these being dependent to a significantly reduced extent or not at all on the orientation of the component produced in the powder material and in particular relative to the protective gas flow direction. This succeeds in particular in that a larger range of angles for the feed direction is made accessible than if only the predetermined useful angular range were used. Since the feed angle is selected only for the minority of powder material layers in the blocking angle range, there is no or at least no relevant impairment of the component quality due to the above discussed pollutant problem. At the same time, the useful angular range can advantageously be chosen to be narrow.

In one embodiment of the method, the feed angle is selected by keeping the protective gas flow direction constant, with a scanner device being suitably controlled for displacing the energy beam within the working area - i.e. with a specific feed direction - in order to select the feed direction and thus the feed angle. The direction of feed is thus changed with a constant flow direction of the protective gas in order to set, in particular to change, the feed angle. In another, alternative embodiment of the method, the feed angle is selected by keeping the feed direction constant, with the protective gas flow direction being changed in order to set, in particular to change, the feed angle. In a further, alternative embodiment of the method, the feed angle is selected by changing and coordinating the feed direction and the protective gas flow direction in order to set, in particular to change, the feed angle.

In particular, the scanning direction is in a plane defined by the working area, ie in a powder material layer, perpendicular to the feed direction.

In the context of the present technical teaching, the fact that the feed angle between the powder material layers is changed means in particular that the feed angle is not the same over all powder material layers of the component to be produced. In one embodiment of the method, the feed angle is changed from layer to layer. However, an embodiment of the method is also possible in which the feed angle is kept constant over some layers, it being possible in particular to change it between groups of layers.

A normal of the direction of flow of the protective gas is understood as meaning an axis or direction which is in a plane defined by the working area, ie in a layer of powder material, perpendicular to the direction of flow of the protective gas.

The useful angular range is in particular an angular range in which the pollutant problem discussed above does not occur, since the feed direction is aligned at least in part against the flow direction of the protective gas. This in turn means that the feed direction in the case of vectorial decomposition in the plane defined by the working area, ie in a powder material layer, has at least one vector component which is oriented anti-parallel to the protective gas flow direction. Since the feed direction advantageously at the same time encloses an angle with the normal of the protective gas flow direction that is greater than the predetermined feed limit angle, the problem of pollutants is avoided in a particularly effective manner. In particular, this ensures that the scanning direction, ie the direction of the vectors perpendicular to the feed direction, encloses an angle with the protective gas flow direction that is greater than the predetermined feed limit angle. This means that the vectors within the useful angular range are in no case aligned exactly parallel or anti-parallel to the direction of flow of the protective gas. In particular, the useful angular range is an angular range that is permitted for the feed direction.

In one embodiment of the method, the feed limit angle is chosen to be 20°, or 22.5°, or 30°.

In contrast, the blocking angle range is, in particular, an angle range in which there is fundamentally the risk of the pollutant problem discussed above. In particular, this is either the case because the feed direction is oriented component-wise in the direction of the direction of flow of the protective gas and/or because the scanning direction is almost collinear or collinear with the direction of flow of the protective gas. The blocking angle range is therefore in particular an angle range that is fundamentally forbidden for the feed direction, which is exceptionally released for a minority of powder material layers within the scope of the present technical teaching in order to achieve the above-mentioned advantages with regard to the mechanical properties of the resulting components.

In one embodiment of the method, the blocking angle range is an angle range that is complementary to the useful angle range in relation to the full circle. In particular, the union of the blocking angle range and the useful angle range is the complete angle range of the full circle from--depending on the angle specification--0 to 2π or 0° to 360°. The degree numbers given below always refer to a complete angular range of the full circle from 0° to 360°.

Additive or generative manufacturing or production of a component means in particular a layered construction of a component from powder material - powder material layer for powder material layer - understood, in particular a powder bed-based method for producing a component in a powder bed, in particular a Manufacturing process selected from a group consisting of selective laser sintering, laser metal fusion (LMF), direct metal laser melting (DMLM), laser net shaping manufacturing (LNSM), and a Laser Engineered Net Shaping (LENS).

An energy beam is generally understood to mean directed radiation that can transport energy. This can generally involve particle radiation or wave radiation. In particular, the energy beam propagates through the physical space along a propagation direction and thereby transports energy along its propagation direction. In particular, it is possible by means of the energy beam to deposit energy locally in the work area.

In a preferred embodiment, the energy beam is an optical working beam. An optical working beam is to be understood in particular as directed electromagnetic radiation, continuous or pulsed, which is suitable in terms of its wavelength or a wavelength range for the additive or generative manufacturing of a component from powder material, in particular for sintering or melting the powder material. In particular, an optical working beam means a laser beam that can be generated continuously or in a pulsed manner. The optical working beam preferably has a wavelength or a wavelength range in the visible electromagnetic spectrum or in the infrared electromagnetic spectrum, or in the overlap region between the infrared range and the visible range of the electromagnetic spectrum.

A working area is understood to mean in particular an area, in particular a plane or surface, in which the powder material is arranged and which is locally irradiated with the energy beam in order to locally solidify the powder material. In particular, the powder material is sequentially arranged in layers in the work area and is locally irradiated with the energy beam in order to produce a component—layer by layer.

The fact that an energy beam is applied locally to the work area means in particular that the energy beam is not applied to the entire work area globally - neither instantaneously nor sequentially - but rather that the work area is covered in places, in particular at individual, connected or separate locations, with the Energy beam is applied, wherein the energy beam is shifted in particular by means of the scanner device within the work area. The fact that the energy beam is applied selectively to the work area means in particular that the energy beam is applied to the work area at selected, predetermined points or locations or in selected, predetermined areas. The working area is in particular a layer of powder material or a preferably contiguous area of a layer of powder material which can be reached by the energy beam using the scanner device, i.e. it includes in particular those points, locations or areas of the layer of powder material that can be impinged on by the energy beam.

A vector or irradiation vector is understood to mean, in particular, a continuous, preferably linear displacement of the energy beam in the work area over a specific distance with a specific direction of displacement, the scanning direction. The irradiance vector includes the direction or orientation of the displacement as its orientation. The fact that the displacement takes place continuously means in particular that it takes place without dropping or interrupting the energy beam, in particular without a jump. The fact that the irradiation preferably takes place linearly means in particular that it takes place along a straight line.

According to a development of the invention, it is provided that the feed angle is selected in such a way that for the minority of powder material layers - in particular exclusively - it lies in a predetermined exceptional angle range within the blocking angle range, in which the feed direction coincides with the normal of the protective gas flow direction encloses an angle which is smaller than the predetermined feed limit angle, preferably smaller than a predetermined exception limit angle. In one embodiment of the method, the predetermined exception limit angle is 10° or 8°.

Alternatively or additionally, the feed direction in the exceptional angular range is aligned at least in components in the direction of the flow direction of the protective gas, wherein if the direction of feed is aligned at least in components in the direction of the flow direction of the protective gas, the direction of feed also encloses an angle with the normal of the direction of flow of the protective gas , which is smaller than the predetermined exception limit angle.

The procedures described advantageously ensure that any effects of the pollutant problem discussed above are minimal at most, and preferably do not occur. In particular, those areas of the locking angle range for the feed direction are not used in which the pollutant problem occurs particularly severely. In particular, the Exceptional angle range no angles in which the feed direction is aligned almost parallel or parallel to the shielding gas flow direction.

According to a development of the invention, it is provided that the predetermined useful angular range - in the mathematically positive sense, in particular in a plan view of the working area - from 110° to 250°, preferably from 112.5° to 247.5°, preferably from 120° up to 240°. In particular in these angular ranges, the pollutant problem discussed above is significantly reduced or does not occur.

Alternatively or additionally, the predetermined blocking angle range includes all angles outside of the predetermined useful angle range. In particular, the blocking angle range—in the mathematically positive sense—is between 250° and 110°, preferably between 247.5° and 112.5°, preferably between 240° and 120°. As already stated, the blocking angle range can therefore be defined in particular as complementary to the useful angle range.

Alternatively or additionally, the predetermined exceptional angular range is the union of two separate partial angular ranges, with a first partial angular range of the two partial angular ranges from 80° to 100°, preferably from 82° to 98°, or from 80° to 90 °, preferably from 82° to 90°, or from 90° to 100°, preferably from 90° to 98°. A second partial angular range of the two partial angular ranges is from 260° to 280°, preferably from 262° to 278°, or from 270° to 280°, preferably from 270° to 278°, or from 260° to 270°, preferably from 262° to 270°. Accordingly, in one embodiment of the method, the partial angular ranges can each be arranged completely within a half-space which is separated from another half-space by an axis extending perpendicularly to the direction of flow of the protective gas; however, in another embodiment, the partial angular ranges can also extend in both half-spaces.

In particular, by releasing the angular ranges mentioned for a small number of powder material layers, the reproducibility of the mechanical properties for the components to be produced can advantageously be ensured, with the feed direction also being selected for the small number of powder material layers in such a way that the pollutant problem discussed above is at least reduced, preferably is avoided.

In one embodiment of the method, either both partial angular ranges are defined such that they extend in both half-spaces, or both partial angular ranges are defined such that they each only extend in one half-space, preferably in the same half-space. In particular, in a first embodiment of the method, the first partial angular range is from 80° to 100°, preferably from 82° to 98°, and the second partial angular range is from 260° to 280°, preferably from 262° to 278°. In another, second embodiment of the method, the first partial angular range is from 80° to 90°, preferably from 82° to 90°, and the second partial angular range is from 270° to 280°, preferably from 270° to 278° . In another, third embodiment of the method, the first partial angular range is from 90° to 100°, preferably from 90° to 98°, and the second partial angular range is from 260° to 270°, preferably from 262° to 270°. In particular, the scanning direction is aligned approximately collinear or collinear with the flow direction of the protective gas in the partial angular ranges mentioned.

According to a development of the invention, it is provided that the feed angle for the small number of powder material layers is selected from a group consisting of: 80°, 85°, 90°, 95°, 100°, 260°, 265°, 270°, 275 °, and 280°. In particular, it is possible for only specific angles, in particular from the group mentioned here, to be selected for the feed direction for the minority of powder material layers. In this way, the difficulties associated with the pollutant problem discussed above can be avoided particularly effectively. In the case of the angles mentioned, the scanning direction is in particular aligned approximately collinear or collinear with the direction of flow of the protective gas.

According to a further development of the invention, it is provided that the feed angle is selected in such a way that the minimum number of powder material layers is at most 17%, preferably at most 13%, preferably at most 12.5%, preferably at most 10%, preferably at most 7%, preferably at most 5% , preferably at most 4%, based on the total number of all powder material layers of the component to be produced or produced. The difficulties associated with the pollutant problem discussed above can thus be avoided in a particularly effective manner. It has been shown that the advantages realized in the context of the present technical teaching with regard to the mechanical properties of the resulting components also occur when the feed angle is selected outside the useful angle range for only a small proportion of the powder material layers. This effect results in particular from the fact that when a new layer of powder material is irradiated with the energy beam, there are usually up to four underlying powder material that have already been irradiated layers are at least partially melted again.

In one embodiment of the method, the powder material layers belonging to the minority of powder material layers are evenly distributed over the total number of powder material layers. In this way, the resulting components are particularly homogeneous in terms of their mechanical properties, in particular their breaking strength.

According to a development of the invention, it is provided that the feed angle for every sixth layer of powder material, preferably for every eighth layer of powder material, preferably for every tenth layer of powder material, preferably for every fifteenth layer of powder material, preferably for every twentieth layer of powder material, preferably for every twenty-fifth layer of powder material, in the predetermined lock -Angle range, preferably in the predetermined exceptional angle range, is selected.

According to a development of the invention, it is provided that the feed angle is selected in such a way that it does not lie in the blocking angle range for any two powder material layers arranged directly one above the other. In this way, disadvantages can be avoided in a particularly effective manner, which could arise if powder material layers lying directly one on top of the other were affected by the pollutant problem discussed above.

According to a development of the invention, it is provided that the feed angle is selected differently for powder material layers arranged directly one above the other. This contributes in a particularly advantageous manner to improving the mechanical properties, in particular the breaking strength of the component to be produced, and also overall to increasing the reproducibility of the mechanical properties of a plurality of components to be produced within the scope of the method proposed here. In particular, this avoids anisotropies that can result from repetitions of the same feed direction; in addition, pore formation, which is disadvantageous for the mechanical properties, is reduced.

According to a development of the invention, it is provided that the feed angle is changed from powder material layer to powder material layer by a predetermined angular amount, or randomly, or pseudo-randomly. This configuration advantageously contributes to reducing or avoiding the repetition of certain feed directions and in particular repetitions of certain sequences of feed directions, i.e. in particular the regular or even periodic recurrence of feed directions, in particular if the predetermined angular amount is suitably selected, or if the feed angle is changed randomly or pseudo-randomly. In this way, the mechanical properties, in particular the breaking strength, of the components to be produced can be improved in a particularly effective manner, anisotropies can be avoided and the formation of pores can be reduced.

In the context of the present technical teaching, “pseudo-random” means in particular that the change in the feed angle or feed angles is not selected randomly in the strict sense, but according to an algorithm, which results in a sequence of feed angles that are subject to predetermined criteria can be regarded as random, or at least does not follow any simple rule, and in particular no rule which can be easily derived from the sequence of feed angles. In contrast, “random” in the context of the present technical teaching is understood to mean either a genuinely random selection of the feed angle or the use of a random number generator, in particular a random number generator implemented in a computing device.

In one embodiment of the method, the blocking angle range is avoided when changing the feed angle for the majority of the powder material layers, in particular discarded or skipped, with the blocking angle range or the exception angle range being permitted for the minority of powder material layers.

In the context of the present technical teaching, the fact that the blocking angle range is discarded means in particular that a feed angle determined by regular change, randomly, pseudo-randomly or in some other way that falls within the blocking angle range is not suitable for the irradiation of the work area with the energy beam is used, but that rather - a new feed angle is determined - in particular based on this determined feed angle. For each feed angle determined, a check is made as to whether the feed angle falls within the blocking angle range, and the feed angle determined is discarded if it falls into the blocking angle range.

In the context of the present technical teaching, the fact that the blocking angle range is skipped is understood in particular to mean that the blocking angle range is left out when the feed angle is determined, so that no feed angles that are determined that would fall into the blocking angle range result in the first place. There is then no need for a separate check as to whether a determined feed angle falls within the blocking angle range. At For example, if a change in the feed angle by a predetermined angle starting from a specific starting angle would lead to a result angle that falls within the blocking angle range, the blocking angle range can be omitted in such a way that the predetermined angle is divided into a first partial angular amount and a second partial angular amount, the first partial angular amount being determined from the specific starting angle to a beginning of the blocking angle range, the second partial angular amount remaining at the predetermined angular amount to an end of the blocking angle range is added. The feed angle resulting in this way is then itself not in the blocking angle range. Alternatively, if a change in the feed angle by a predetermined angle starting from a specific starting angle would lead to a result angle that falls within the blocking angle range, the blocking angle range can be left out in such a way that the predetermined angle does not occur the determined start angle, but is added to the end of the blocking angle range.

In one embodiment of the method, the feed direction is rotated from powder material layer to powder material layer by a predetermined angular amount. According to a first embodiment, it is possible for the pivot point to lie outside the working area. In another, second embodiment, it is possible for the pivot point to lie within the working area. In a further embodiment, it is possible for a separate pivot point to be defined within the working area for a plurality of areas exposed to the energy beam, in particular a plurality of components and/or a plurality of connected locations. Preferably, the angle of rotation about the plurality of pivot points is the same for all areas of the plurality of areas and/or in each layer of powder material. In particular, an origin of the areas can be suitably selected in each case in order in particular to minimize a number of areas, for example stripes, in a powder material layer and/or a number of short vectors in each coherent area.

According to a development of the invention, it is provided that the powder material layers are irradiated with the at least one energy beam in the form of strips, with the strips extending in the feed direction and being formed from the vectors oriented collinearly with one another perpendicular to the feed direction. In this case, the vectors extend in particular in the width direction of the respective strip, that is to say perpendicular to the longitudinal extension of the strip, that is to say to the feed direction. The vectors preferably extend along the entire width of the respective strip. The width of the strip thus preferably defines the length of the vectors - or vice versa. In particular, a strip is preferably swept sequentially with a multiplicity of vectors aligned in the width direction, ie in the scanning direction, and offset from one another or arranged next to one another in the longitudinal direction of the strip, ie in the feed direction.

According to a further development of the invention, it is provided that vectors which are directly adjacent to one another in the feed direction are aligned parallel or antiparallel to one another along the scanning direction. In one embodiment of the method, vectors immediately adjacent to one another in the feed direction are aligned antiparallel to one another along the scanning direction, in particular also for the minority of powder material layers in the blocking angle range or in the exception angle range. This alignment of the vectors, which is unfavorable per se with regard to the pollutant problem discussed above, in which half of the vectors can be aligned approximately collinear or collinear with the direction of flow of the protective gas, is advantageous for the mechanical properties of the resulting component and is acceptable from this point of view or also an overall advantage that only a minority of powder material layers are affected by the pollutant problem at all.

According to a development of the invention, it is provided that the predetermined angular amount by which the feed direction is rotated from powder material layer to powder material layer is selected to be different from 10°, 45°, 90°, 50° and 180°. This choice advantageously avoids such angular amounts that would lead to a frequent, in particular periodic recurrence of identical feed directions.

In one embodiment of the method, the predetermined angular amount is selected to be greater than 10°, preferably greater than 20°. This has proven to be advantageous precisely from the point of view of avoiding a frequent recurrence of identical feed directions.

In one embodiment of the method, the predetermined angular amount does not have a common divisor of 360° that differs from one. This contributes in a particularly favorable manner to avoiding a frequent recurrence of identical feed directions.

In one embodiment of the method, the predetermined angular amount is preferably chosen to be 54° or 67°. Especially with these angles, a frequent recurrence of identical feed directions is avoided in a special way.

According to a development of the invention, it is provided that a predetermined additional blocking angle range is taken into account for the feed angle, which is from 170° to 190°, preferably from 160° to 200°, preferably from 150° to 210°, the feed angle being at least is selected for the majority of the powder material layers outside the predetermined additional blocking angle range. By leaving out a certain angular range in the vicinity of 180° to the protective gas flow direction for the feed angle, it is advantageously achieved that, in particular, strip-shaped areas of a powder material layer can be irradiated simultaneously with greater freedom - in particular with a plurality of energy beams - without there is a mutual influence of the strip-shaped areas with pollutants. In particular, pollutants from an irradiated area can only penetrate increasingly smaller sub-areas of immediately adjacent irradiated areas with increasing distance of the advance angle of 180°, so that there is greater freedom for simultaneous irradiation in the immediately adjacent irradiated areas.

In particular, the predetermined additional blocking angle range lies within the predetermined useful angle range. In particular, the additional blocking angle range thus limits the predetermined useful angle range, in particular to at least a partial useful angle range. The predetermined additional blocking angle range divides in particular the useful angle range into two separate partial useful angle ranges, so that the remaining useful angle range that is still permitted for the majority of the powder material layers is the union of the two separate partial useful angle ranges . For example, a first partial useful angle range extends from 120° to 150°, and a second partial useful angle range extends from 210° to 240°, if on the one hand the predetermined useful angular range extends from 120° to 240° and on the other hand the predetermined additional blocking angle range from 150 ° to 210 °.

In the context of the present technical teaching, the fact that the advance angle is selected outside of the predetermined additional blocking angle range means in particular that the predetermined additional blocking angle range for the advance angle is left out, i.e. that the advance angle is not selected in the predetermined additional blocking angle range .

In one embodiment of the method, the feed angle for all layers of powder material is selected outside of the predetermined additional blocking angle range. In another embodiment of the method, it is possible that the feed angle for the minority of powder material layers—in addition to the predetermined blocking angle range or the predetermined exceptional angle range—can also be selected in the predetermined additional blocking angle range.

The object is also achieved by creating a manufacturing device for the additive manufacturing of components from a powder material. The manufacturing device has a beam generating device that is set up to generate at least one energy beam. In addition, the manufacturing device has a powder coating device that is set up to arrange the powder material successively powder material layer by powder material layer in a working area. The production device also has a scanner device that is set up to locally and selectively irradiate the work area with the at least one energy beam in order to use the at least one energy beam to produce a component layer by layer from the powder material arranged in the work area. Furthermore, the production device has a protective gas device which is set up to generate a protective gas flow with a predetermined protective gas flow direction over the working area. Finally, the manufacturing device has a control device that is operatively connected to the scanner device and set up to control the scanner device. The control device is further set up to displace the at least one energy beam in the powder material layers at least in regions in the form of vectors oriented collinearly to one another along a scanning direction and arranged next to one another along a feed direction. The control device is also set up to change a feed angle between the powder material layers, which the feed direction includes with the protective gas flow direction, and to select the feed angle in such a way that the feed angle for a plurality of the powder material layers is in a predetermined useful angle range. in which the feed direction is at least partially aligned counter to the flow direction of the protective gas, wherein at the same time the feed direction encloses an angle with a normal of the flow direction of the protective gas which is greater than a predetermined feed limit angle, and that the feed angle for a minority of the powder material layers in one predetermined blocking angle range is outside of the useful angle range. In connection with the manufacturing device, there are in particular the advantages that have already been explained in connection with the method.

The production device is set up in particular to carry out the method according to the invention or one or more of the previously described embodiments of the method. In particular, the control device is preferably set up to carry out the method according to the invention or one or more of the previously described embodiments of the method.

In one embodiment of the production device, the control device is also operatively connected to the protective gas device and set up to control it, in particular to set the direction of flow of the protective gas, in particular to change the direction of flow of the protective gas.

The manufacturing device is set up in particular to carry out at least one additive or generative manufacturing method, which is selected in particular from a group consisting of selective laser sintering, laser metal fusion (laser metal fusion - LMF), direct metal laser melting (Direct Metal Laser Melting - DMLM), Laser Net Shaping Manufacturing (LNSM), and Laser Engineered Net Shaping (LENS).

In one embodiment of the manufacturing device, the beam generating device is a laser.

In one embodiment of the production device, the powder coating device has a powder conveying device that is set up to convey powder material from a powder supply into the work area and preferably to arrange the powder material in the work area—in particular homogeneously—in a powder material layer. The powder conveying device is preferably designed as a slide.

The work area is preferably arranged on a construction platform that can be lowered step by step in order to be able to successively arrange the powder material layers on top of one another in a constant construction level. The powder store preferably has a lifting platform that can be raised step by step in order to be able to remove powder for a new layer of powder material from the powder store and transfer it to the work area.

The scanner device preferably has at least one scanner, in particular a galvanometer scanner, piezo scanner, polygon scanner, MEMS scanner, and/or a working head or processing head that can be displaced relative to the work area—preferably at least one for each energy beam of a plurality of energy beams separately from the respective energy beam associated such element. The devices proposed here are particularly suitable for shifting the at least one energy beam within the working area between a plurality of irradiation positions.

A working head or processing head that can be displaced relative to the work area is understood here in particular to mean an integrated component of the production device which has at least one radiation outlet for at least one energy beam, the integrated component, i.e. the working head, as a whole along at least one displacement direction, preferably along two mutually perpendicular directions of displacement, is displaceable relative to the work area. Such a working head can, in particular, be designed in the form of a portal or be guided by a robot. In particular, the working head can be designed as a robot hand of a robot.

The protective gas device preferably has at least one protective gas outlet, in particular a nozzle, preferably a plurality of protective gas outlets, in particular nozzles, arranged in particular next to one another and preferably aligned parallel to one another. The at least one protective gas outlet is set up in particular to cause the protective gas to flow out of the protective gas outlet in a directed manner and thus to define the direction of flow of the protective gas.

According to a preferred embodiment, the protective gas device additionally has at least one protective gas inlet, in particular a plurality of protective gas inlets which are preferably arranged next to one another and in particular aligned parallel to one another, through which the protective gas can enter the protective gas device again from the working area. In particular, the at least one protective gas inlet is preferably arranged opposite the at least one protective gas outlet when viewed in the protective gas flow direction, with the working area being arranged between the at least one protective gas inlet and the at least one protective gas outlet. In a preferred embodiment, the protective gas device has a suction device, in particular a pump, by means of which the protective gas can be sucked out of the work area via the at least one protective gas inlet. The direction of flow of the protective gas over the working area can be specified with particularly high precision, in particular by means of a combination of defined outflow of the protective gas from the at least one protective gas outlet and defined suction of the protective gas via the at least one protective gas inlet.

The control device is preferably selected from a group consisting of a computer, in particular a personal computer (PC), a plug-in card or control card, and an FPGA board. In a preferred configuration, the control device is an RTC6 control card from SCANLAB GmbH, in particular in the configuration currently available on the date determining the seniority of the present property right.

• 1 eine schematische Darstellung eines Ausführungsbeispiels einer Fertigungsvorrichtung zum additiven Fertigen eines Bauteils aus einem Pulvermaterial;
• 2 eine schematische Erläuterung eines Ausführungsbeispiels eines Verfahrens zum additiven Fertigen eines Bauteils aus einem Pulvermaterial, und
• 3 eine weitere schematische Erläuterung des Ausführungsbeispiels des Verfahrens.

The invention is explained in more detail below with reference to the drawing. show:

• 1 a schematic representation of an embodiment of a manufacturing device for the additive manufacturing of a component from a powder material;
• 2 a schematic explanation of an embodiment of a method for additively manufacturing a component from a powder material, and
• 3 a further schematic explanation of the exemplary embodiment of the method.

1 shows a schematic representation of an embodiment of a manufacturing device 1 for the additive manufacturing of a component 3 from a powder material.

The manufacturing device 1 has a beam generating device 5, which is set up to generate at least one energy beam 7, here a plurality of energy beams 7, a first energy beam 7.1 and a second energy beam 7.2. For this purpose, the beam generating device 5 can have, for example, a plurality of lasers, or else a laser which interacts with a beam splitter device, for example a beam splitter, in order to generate the plurality of energy beams 7 . In a preferred embodiment, the energy beams 7 are in the form of laser beams.

The displacement device 1 has a powder coating device 8 which is set up to arrange the powder material successively powder material layer by powder material layer in a working area 11 . The powder coating device 8 is only shown schematically here; it preferably comprises a slide for moving the powder material from a powder supply to the working area 11 and for distributing the powder material in the working area 11 in the form of a preferably homogeneous layer of powder material. For this purpose, the work area 11 is arranged in particular on a construction platform that can be lowered step by step, in order to be able to produce the various layers of powder material one on top of the other. At the same time, the supply of powder is preferably stored on a lifting platform in order to be able to gradually raise the powder to the level of the working area 11 and remove it there with the pusher and transport it to the working area 11 .

The production device 1 also has a scanner device 9, which is set up to irradiate the working area 11 locally and selectively with the at least one energy beam 7, at least at times, in order to use the at least one energy beam 7 to cut the component 3 from the powder material arranged in the working area 11 in layers to manufacture. The scanner device 9 can in particular have a separately controllable scanner 13 for each energy beam 7, for example a galvo scanner.

The production device 1 also has a protective gas device 15, which is set up to induce a protective gas flow with a defined protective gas flow direction--represented here by the first arrows P1, with only one of the first arrows being marked with the corresponding reference number for the sake of clarity to generate the workspace 11.

In addition, the production device 1 has a control device 17 which is operatively connected to the scanner device 9, here in particular to the individual scanners 13, and set up to control the scanner device 9, in particular the individual scanners 13 separately.

The control device 9 is also set up to displace the at least one energy beam 7 in the powder material layers at least in regions in the form of vectors 18 oriented collinearly with one another along a scanning direction AR and arranged next to one another along a feed direction VR, by a feed angle α, which the feed direction VR has including the protective gas flow direction, between the powder material layers, and to select the feed angle α in such a way that the feed angle α for a majority of the powder material layers lies in a predetermined useful angular range in which the feed direction VR is at least partially opposite to the protective gas flow direction is aligned, wherein at the same time the feed direction VR encloses an angle with a normal of the protective gas flow direction which is greater than a predetermined feed limit angle, and that the feed angle α for a minority of the powder material layers n is in a predetermined blocking angle range outside of the useful angle range.

It is possible for the control device 9 to be additionally operatively connected to the protective gas device 15 and set up to control it, in particular about the protective gas flow direction set, especially to change the shielding gas flow direction.

The control device 9 is set up in particular to carry out a method which is explained in more detail below.

The working area 11, in particular successively the powder material layers, is preferably irradiated with at least one energy beam 7 in the form of strips 19 which extend in the feed direction VR and which are formed from the vectors 18 oriented collinearly with one another perpendicular to the feed direction VR. In 1 two strips 19 are shown, a first strip 19.1 and a second strip 19.2, which are directly adjacent to one another and oriented parallel to one another. It is possible that the feed direction VR is the same for all strips 19 of a given powder material layer. However, it is also possible for different strips 19 with different feed directions VR to be formed within a layer of powder material.

Vectors 18 directly adjacent to one another are preferably aligned antiparallel to one another along the scanning direction AR. However, it is also possible for the vectors 18 to be aligned parallel to one another along the scanning direction AR.

2 shows a schematic explanation of an embodiment of a method for additively manufacturing a component from a powder material.

Elements that are the same and have the same function are provided with the same reference symbols in all figures, so that reference is made to the previous description in each case.

2 shows schematically the working area 11 with the protective gas flow direction indicated by the arrow P1 and an imaginary circle K with angle information to explain the different angular ranges for the feed angle α, which the also schematically indicated feed direction VR can assume with the protective gas flow direction. The full circle covers 360°; at 0° the feed direction VR is aligned parallel to the direction of flow of the protective gas, at 180° the direction of feed VR is aligned antiparallel to the direction of flow of the protective gas.

For the majority of the powder material layers, the feed angle α is selected in a useful angular range 21 which, in the exemplary embodiment shown here, ranges from 110° to 250°—in the mathematically positive sense. The predetermined limit feed angle is 20° here. In other exemplary embodiments of the method, the useful angle range 21 extends from 112.5° to 247.5°, or from 120° to 240°.

A blocking angle range 22 is also shown, which is designed to complement the useful angle range 21, ie it extends in particular--in the mathematically positive sense--between 250° and 110°. In other exemplary embodiments of the method, the blocking angle range extends between 247.5° and 112.5°, or between 240° and 120°.

The feed angle α is preferably selected in such a way that it lies in a predetermined exception angle range 23 within the blocking angle range 22 for the minority of powder material layers—in particular exclusively. In the exceptional angular range 23, the feed direction VR encloses an angle with the normal of the protective gas flow direction that is smaller than the predetermined feed limit angle, and/or the feed direction VR is at least partially aligned in the direction of the protective gas flow direction. If the feed direction VR is at least partially aligned in the direction of the protective gas flow direction, the feed direction VR also encloses an angle with the normal of the protective gas flow direction that is smaller than a predetermined exception limit angle, which is preferably 10° or 8°.

In the exemplary embodiment shown here, the predetermined exceptional angular range 23 is the union of two separate partial angular ranges 23.1, 23.2, with a first partial angular range 23.1 of the two partial angular ranges 23.1, 23.2 ranging from 80° to 90°. In other exemplary embodiments of the method, the first partial angular range 23.1 preferably ranges from 80° to 100°, preferably from 82° to 98°, or from 82° to 90°, or from 90° to 100°, preferably from 90° to 98° °. A second partial angular range 23.2 of the two partial angular ranges 23.1, 23.2 extends from 270° to 280° in the exemplary embodiment shown here. In other exemplary embodiments of the method, the second partial angular range 23.2 preferably ranges from 260° to 280°, preferably from 262° to 278°, or from 270° to 278°, or from 260° to 270°, preferably from 262° to 270 °.

In yet another embodiment of the method, the feed angle α for the minority of powder material layers is preferably selected from a group consisting of: 80°, 85°, 90°, 95°, 100°, 260°, 265°, 270°, 275 °, and 280°.

A predetermined angle that is not explicitly shown here is preferably used for the feed angle additional blocking angle range is taken into account, which is from 170° to 190°, preferably from 160° to 200°, preferably from 150° to 210°, the feed angle being selected outside the predetermined additional blocking angle range at least for the majority of the powder material layers.

The feed angle α is preferably selected in such a way that the minority of powder material layers is at most 17%, preferably at most 13%, preferably at most 12.5%, preferably at most 10%, preferably at most 7%, preferably at most 5%, preferably at most 4% to the total number of all powder material layers of the component 3 to be produced or produced, wherein the powder material layers belonging to the minority of powder material layers are preferably distributed evenly over the total number of powder material layers.

The feed angle α is preferred for every sixth layer of powder material, preferably for every eighth layer of powder material, preferably for every tenth layer of powder material, preferably for every 15th layer of powder material, preferably for every 20th layer of powder material, preferably for every 25th layer of powder material, in the predetermined blocking angle range 22 , preferably in the predetermined exception angle range 23 selected.

The feed angle α is preferably selected in such a way that it does not lie in the blocking angle range 22 for any two powder material layers arranged directly one above the other.

The feed angle α is preferably selected differently for powder material layers arranged directly one above the other.

The feed angle α is preferably changed from powder material layer to powder material layer by a predetermined angular amount, or randomly, or pseudo-randomly, with the blocking angle range 22 being avoided for the majority of the powder material layers, in particular being discarded or skipped. The blocking angle range 22 or the exception angle range 23 is permitted for the minority of powder material layers.

The predetermined angular amount by which the feed angle α is changed from powder material layer to powder material layer is preferably selected to be different from 10°, 45°, 90°, 50° and 180°. The predetermined angular amount is preferably selected to be greater than 10°, preferably greater than 20°. Preferably, the predetermined angular amount does not have a common divisor of 360° that is different from one. The predetermined angular amount is particularly preferably chosen to be 54° or 67°.

3 shows a further schematic explanation of the exemplary embodiment of the method.

3a) shows a schematic representation of the working area 11 with the first arrow P1, which indicates the protective gas flow direction, and three different types of samples of components 3, which were prepared to evaluate previous methods for additively manufacturing such components 3 and the method proposed here. The components 3 are circular-cylindrical samples, i.e. columnar components 3, which were built up in different positions and orientations in the working area 11: A first sample 3,v was placed with its longitudinal or symmetry axis vertical, i.e. in the direction of the stroke Construction platform of the work area 11 or, to put it another way, aligned in the stacking direction of the powder material layers arranged one on top of the other; a second sample 3,hx was oriented with its long axis horizontal in the working area 11 and perpendicular to the shielding gas flow direction, and a third sample 3,hy was oriented with its long axis horizontal in the working area 11 and in the shielding gas flow direction. Samples of this type were repeatedly produced using both conventional irradiation strategies and the method proposed here, and their mechanical properties, in particular breaking strength, yield point and elongation at break, were examined.

In the diagrams discussed below, different conventionally prepared groups of samples are denoted by the letters A, B, C, D, E and a group of samples prepared using the method proposed here is denoted by the letter X. The data assigned to the individual groups of samples are each - within each group - subdivided into a left and a right area, with the left area, which for the sake of simplicity is only denoted by A and X by way of example with v, contains vertically oriented samples in the manner of the first sample 3, v in 3a) and the right-hand area, also designated hx,hy by way of example only at A and at X, contains data for horizontally oriented samples of the type of the second sample 3,hx and the third sample 3,hy according to FIG 3a) summarizes.

3b) shows the ultimate strength in MPa for the various samples. In this context, it becomes particularly clear that the breaking strength for the conventional methods depends greatly on the position and orientation of the samples in the working area 11 . The strong widening The data for the horizontally oriented samples hx,hy shows that the orientation relative to the direction of flow of the protective gas is to be regarded as a critical parameter. This is unfavorable since the position and orientation is typically determined on the basis of other criteria such as the type, geometry and number of components 3 to be produced within the working area 11, with reproducible results being expected regardless of the position and orientation of the samples. The data for the samples at X produced with the method proposed here now show that the breaking strength is somewhat lower than that according to the conventional method - although still high - but is extremely reproducible, regardless of the position and orientation of the samples.

3c ) shows the yield strength in MPa for the same samples. This results in a 3b) analog picture. Although a slight deviation can be observed here at X between the vertically oriented samples v and the horizontally oriented samples hx,hy, the scatter in the individual data groups at X is much less than for A to E, and in particular there is no scatter prominent dependence on the orientation relative to the shielding gas flow direction, i.e. between hx and hy.

3d ) finally shows the elongation at break As (elongation A5) in % for the same samples. This shows that the elongation at break for the samples produced with the method proposed here at X is higher than for those produced conventionally at A to E, with the dependence on position and orientation and the scattering of the data being lower at the same time. The increased elongation at break of the samples produced using the method proposed here also shows that, despite the somewhat reduced breaking strength, there is no deteriorated quality, and in particular no larger number of pores or similar defects are introduced into the samples. In particular, no predetermined breaking points are produced with the method proposed here, which namely would otherwise have reduced the elongation at break. Micrographs of the samples produced using the method proposed here have shown that a density of over 99.9% can be assumed.

Claims (14)

A method for additively manufacturing a component (3) from a powder material, wherein - the powder material is successively arranged powder material layer by powder material layer in a working area (11), wherein - Powder material layers of the powder material are each locally selectively irradiated with at least one energy beam (7) in order to selectively locally solidify the powder material in the work area (11) by means of the energy beam (7) and thus to produce the component (3) in layers, wherein - A protective gas flow with a specific protective gas flow direction is generated over the working area (11), wherein - the at least one energy beam (7) is displaced in the powder material layers at least in regions in the form of vectors (18) oriented collinearly with one another along a scanning direction (AR) and arranged next to one another along a feed direction (VR), wherein - A feed angle (α), which includes the feed direction (VR) with the protective gas flow direction, is changed between the layers of powder material, wherein - the feed angle (α) is selected in such a way that the feed angle (α) for a plurality of the powder material layers lies in a predetermined useful angular range (21), in which the feed direction (VR) is at least partially aligned opposite to the protective gas flow direction, wherein at the same time the feed direction (VR) encloses an angle with a normal of the protective gas flow direction which is greater than a predetermined feed limit angle, wherein - the feed angle (α) for a minority of the powder material layers is in a predetermined blocking angle range (22) outside the useful angle range (21). procedure after claim 1 , wherein the feed angle (α) is selected in such a way that for the minority of powder material layers it lies in a predetermined exception angle range (23) within the blocking angle range, in which the feed direction (VR) forms an angle with the normal of the protective gas flow direction includes, which is smaller than the predetermined feed limit angle, and / or in which the feed direction (VR) is at least partially aligned in the direction of the protective gas flow direction, wherein if the feed direction (VR) is at least partially aligned in the direction of the protective gas flow direction is, the feed direction (VR) at the same time with the normal of the flow direction of the protective gas includes an angle which is smaller than a predetermined exception limit angle. Method according to one of the preceding claims, wherein - the predetermined useful angular range (21) is from 110° to 250°, preferably from 112.5° to 247.5°, preferably from 120° to 240°, and/or wherein - the predetermined blocking angle range (22) includes all angles outside of the predetermined useful angle range (21), the blocking angle range (22) being in particular between 250° and 110°, preferably between 247.5° and 112.5°, preferably between 240° and 120°, and/or wherein - the predetermined exceptional angular range (23) is the union of two separate partial angular ranges (23.1, 23.2). , wherein a first partial angular range (23.1) of the two partial angular ranges (23.1, 23.2) from 80° to 100°, preferably from 82° to 98°, or from 80° to 90°, preferably from 82° to 90° , or from 90° to 100°, preferably from 90° to 98°, with a second partial angular range (23.2) of the two partial angular ranges (23.1, 23.2) from 260° to 280°, preferably from 262° to 278°, or from 270° to 280°, preferably from 270° to 278°, or from 260° to 270°, preferably from 262° to 270°. Procedure according to one of Claims 1 or 2 , wherein the feed angle (α) for the minority of powder material layers is selected from a group consisting of: 80°, 85°, 90°, 95°, 100°, 260°, 265°, 270°, 275°, and 280 °. Method according to one of the preceding claims, wherein the feed angle (α) is chosen such that the minority of powder material layers is at most 17%, preferably at most 13%, preferably at most 12.5%, preferably at most 10%, preferably at most 7%, preferably at most 5%, preferably at most 4%, based on the total number of all powder material layers of the component (3) to be produced or produced, the powder material layers belonging to the minority of powder material layers preferably being distributed evenly over the total number of powder material layers. Method according to one of the preceding claims, wherein the feed angle (α) for every sixth powder material layer, preferably for every eighth powder material layer, preferably for every tenth powder material layer, preferably for every 15 powder material layer, preferably for every 20 powder material layer, preferably for every 25 powder material layer , is selected in the predetermined blocking angle range (22), preferably in the predetermined exception angle range (23). Method according to one of the preceding claims, in which the feed angle (α) is selected in such a way that it does not lie in the blocking angle range (22) for any two powder material layers arranged directly one above the other. Method according to one of the preceding claims, in which the feed angle (α) is selected differently for powder material layers arranged directly one above the other. Method according to one of the preceding claims, wherein the feed angle (α) from powder material layer to powder material layer is changed by a predetermined angular amount, or randomly, or pseudo-randomly, the blocking angle range (22) being avoided for the majority of powder material layers, in particular discarded or is skipped, the blocking angle range (22) or the exception angle range (23) being permitted for the minority of powder material layers. Method according to one of the preceding claims, in which the powder material layers are irradiated with the at least one energy beam (7) in the form of strips (19), the strips (19) extending in the feed direction (VR) and from the perpendicular to the feed direction (VR) collinear to each other oriented vectors (18) are formed. Method according to one of the preceding claims, vectors (18) immediately adjacent to one another in the feed direction (VR) being aligned parallel or antiparallel to one another along the scanning direction (AR). Procedure according to one of claims 9 until 11 , wherein the predetermined angle of 10 °, 45 °, 90 °, 50 °, and 180 ° is selected to be different, wherein the predetermined angle is preferably greater than 10 °, preferably greater than 20 °, the predetermined angle is preferably none of one different integer common divisor of 360°, the predetermined angular amount preferably being chosen to be 54° or 67°. Method according to one of the preceding claims, wherein a predetermined additional blocking angle range is taken into account for the feed angle (α), which is from 170° to 190°, preferably from 160° to 200°, preferably from 150° to 210°, wherein the Feed angle (α) is selected at least for the majority of the powder material layers outside of the predetermined additional blocking angle range. Manufacturing device (1) for the additive manufacturing of components (3) from a powder material, having - a beam generating device (5) which is set up to generate at least one energy beam (7), - a powder coating device (8) which is set up to Powder material successive powder material layer by powder material layer in to be arranged in a work area (11), - a scanner device (9) which is set up to locally and selectively irradiate the work area (11) with the at least one energy beam (7) in order to use the at least one energy beam (7) to scan a component (3 ) to produce in layers from the powder material arranged in the working area (11), - a protective gas device (15) which is set up to generate a protective gas flow with a predetermined protective gas flow direction over the working area (11), and with - a control device (17) which is operatively connected to the scanner device (9) and set up to control the scanner device (9), wherein - the control device (17) is further set up to: to leave vectors (18) oriented collinearly to one another along a scanning direction (AR) and arranged next to one another along a feed direction (VR). Gladly, - to change a feed angle (α), which includes the feed direction (VR) with the shielding gas flow direction, between the powder material layers, and to - select the feed angle (α) in such a way that the feed angle (α) for a majority of the powder material layers is in a predetermined useful angular range (21), in which the feed direction (VR) is at least partially aligned against the flow direction of the protective gas, with the feed direction (VR) at the same time enclosing an angle with a normal of the flow direction of the protective gas that is greater than is a predetermined feed limit angle, and that - the feed angle (α) for a minority of the powder material layers in a predetermined blocking angle range (22) lies outside the useful angle range (21).

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