DE102017212565B4 - Method for producing a continuous surface area, irradiation device and processing machine - Google Patents

Abstract

Method for producing a coherent surface area (2) of a three-dimensional component (20) by irradiating a powder layer (3) with at least two processing beams (4a,b; 4a-e), in particular with at least two laser beams, comprising: dividing a primary processing beam (4) into the at least two processing beams (4a,b; 4a-e), guiding the at least two processing beams (4a,b; 4a-e) to a common scanner device (5) for aligning the at least two processing beams (4a,b; 4a-e) via the same scanner mirror(s) (6a, 6b) to different positions (P1, P2; P1 to P5) in a processing plane (E) of the scanner device (5) in which the coherent surface area (2) is located, wherein the production of the coherent surface area (2), which is divided into a plurality of preferably rhomboid, in particular diamond-shaped, rectangular or square partial areas for the irradiation (T1 to T6; T1, T2), comprises:Simultaneous changing of the positions (P1, P2; P1 to P5) of the at least two processing beams (4a,b; 4a-e) in at least two different partial areas (T3, T4) of the contiguous surface area (2) until the powder layer (3) in the at least two partial areas (T3, T4) has completely melted, andSimultaneous changing of the positions (P1, P2; P1 to P5) of the at least two processing beams (4a,b) or of at least two further processing beams (25a-e) in at least two different further partial areas (T5, T6) of the contiguous surface area (2) until the powder layer (3) in the at least two further partial areas (T5, T6) has completely melted.

Description

The present invention relates to a method for producing a continuous surface area of a three-dimensional component by irradiating a powder layer with at least two processing beams, in particular by means of at least two laser beams. The invention also relates to an irradiation device for a processing machine for producing three-dimensional components by irradiating powder layers, comprising: a beam splitter device for splitting a primary processing beam, in particular a laser beam, into at least two processing beams, in particular into at least two laser beams, and a scanner device for aligning the at least two processing beams to different positions in a processing plane of the scanner device, and a processing machine with such an irradiation device.

Three-dimensional components can be manufactured using so-called generative manufacturing processes (also known as additive manufacturing processes). In such processes, the three-dimensional component is generated layer by layer. In so-called selective laser melting or laser sintering (also known as laser metal fusion, LMF), a powder material is locally melted by a high-energy processing beam, in particular a laser beam, in order to produce a layer of the three-dimensional component. The high-energy processing beam, for example in the form of a laser beam, can have an output in the order of several hundred watts.

In order to increase the efficiency or the build rate in the production of three-dimensional components, it is known to use two or more processing beams, in particular two or more laser beams, which are generated by a corresponding number of beam sources and which are directed to a (common) processing area via separate scanner devices. Due to the space available, only a limited number of beam deflection devices, for example in the form of scanner optics, can be accommodated in a processing machine or in an irradiation device. In order to achieve the most efficient (fast) exposure possible, a (primary) processing beam can be split into two or more processing beams using a beam splitter device.

In the WO 2015/191257 A1 describes a method and apparatus for selective laser melting in which multiple laser beams are used simultaneously to increase efficiency in the manufacture of components. In the method, a plurality of laser beams are directed onto a single galvanometer to produce a corresponding plurality of three-dimensional structures or components in a powder bed. The plurality of laser beams can be generated by splitting a primary laser beam into the plurality of laser beams. Each of the plurality of laser beams can be automatically and dynamically focused before being directed onto the galvanometer.

For the efficient production of a three-dimensional component, it is WO 2016/128430 A1 It is known to use an irradiation device with a beam shaping device for shaping the beam profile of the laser beam, in which the length and/or the width of the beam profile can be changed in the processing field. The beam shaping unit can have at least one further optical element for additional shaping of the beam profile, which can be designed as a diffractive optical element, for example. The diffractive optical element can serve to generate the high-energy beams that strike the processing field from a single high-energy beam. The further optical element can also be designed as a wedge-shaped optical element that only covers part of the beam profile in order to spatially separate one or more profile areas of the beam profile from other profile areas of the beam profile.

The EP 2 875 897 B1 describes a method for controlling an irradiation system comprising a plurality of irradiation units. In the method, for example, checkerboard-like irradiation patterns or line- or strip-like irradiation patterns are used to generate a continuous surface area.

Further state of the art is from US 5 508 489A , EP 2 862 651 A1 , US2014 / 0 271 328 A1 , US 2015 / 0 174 827 A1 , DE 10 2015 103 127 A1 US 2016 / 0 136 730 A1 and EP 2 335 848 A1 known.

task of the invention

The invention is based on the object of specifying a method of the type mentioned at the outset as well as an irradiation device and a processing machine with such an irradiation device, with which an efficient production of connected surface areas of a three-dimensional component is possible.

subject matter of the invention

This object is achieved by a method according to claim 1, an irradiation device according to claim 10 and a processing machine according to claim 19.

The process enables an increase in speed when exposing relatively large contiguous areas by dividing the power of the primary processing beam between the two or more processing beams. In contrast to the WO 2015/191257 A1 In the method described, the division into several processing beams is therefore not used to produce several identical, spatially separated components, but to create a contiguous surface area of a layer of one and the same component.

The two or more processing beams run approximately parallel to one another (typically at a small angle) and are aligned with the processing plane via the same beam splitter device, i.e. via the same (scanner) mirror(s). The (focused) processing beams impinge on the processing plane at different (focus) positions, whereby the distance between the (focus) positions is typically comparatively small and can be, for example, less than approximately 1.0 mm. The difference angle between the two processing beams deflected at the scanner device is also typically comparatively small and is usually less than approximately 1°.

In the process, a continuous surface area of the three-dimensional component is created or exposed by dividing it (for example in a preceding process step) into a plurality of sub-areas. The plurality of sub-areas typically forms a regular, grid-like arrangement, for example in the manner of a checkerboard, which covers the continuous surface area. Ideally, the sub-areas do not overlap and ideally border directly on one another. Since the angle at which the processing beams hit the powder layer vary depending on the position in the processing area, there may be an (unwanted) partial overlap of adjacent sub-areas on a scale of usually a maximum of approx. 10% of the respective edge length (length or width) of the sub-areas.

The positions of the two processing beams can be in different sub-areas, so that two or more sub-areas are exposed simultaneously by simultaneously changing the positions of the at least two processing beams. However, the positions of the two or more processing beams can also be in one and the same sub-area, which can be melted more quickly due to the use of two or more processing beams than when using a single processing beam. The additional sub-area(s) that are subsequently or simultaneously exposed with the help of additional processing beams typically do not directly border on the sub-area(s) exposed in the previous step, as this is not ideal for the heat balance of the molten powder material. Therefore, between the steps of melting the sub-area(s) and the subsequent melting of the additional sub-area(s), a change in the alignment of the processing beams in the processing plane can be made using the scanner device in which the processing beams are not activated. After the alignment has been changed, the processing beams are switched on again to expose the other partial area(s).

In one variant, the continuous surface area is surrounded by an edge contour of a layer of the three-dimensional component, wherein the edge contour and/or an edge region formed between the edge contour and the continuous surface area is irradiated with the primary processing beam, in particular with the primary laser beam, or with a further processing beam, in particular with a further laser beam. As a rule, the edge contour of the layer of the three-dimensional component to be produced does not match the edge contour of the continuous surface area, so that a edge region remains between the edge contour and the continuous surface area. The edge region typically has a geometry or a surface into which no part of the continuous surface area fits. The edge region is therefore typically irradiated or melted with a single processing beam. For this purpose, the primary processing beam can be used, which in this case is not split into several processing beams, or a further processing beam can be used, which is generated by a further beam source and/or which is aligned to the processing plane via a further scanner device. If the primary processing beam is used, it is advantageous if the switching between the several processing beams and the primary processing beam can be as dynamic and fast as possible. For this purpose, a beam splitter device can be provided, which can be quickly divided into the beams can be moved in and out of the primary processing beam. The use of a single, non-split processing beam is also advantageous for exposing the edge contour of the layer of the two-dimensional component.

In a further variant, the different positions of the processing beams in the partial area or in the at least two partial areas in the processing plane are offset from one another in a first direction, and the simultaneous change in the positions of the at least two processing beams in the partial area or in the at least two partial areas comprises a simultaneous movement of the processing beams in a second direction, preferably perpendicular to the first direction in the processing plane. In this case, the outer contours of the partial areas typically run parallel to the first or second direction. In this case, the processing beams are typically moved in a scanning movement in a typically straight line along the extent or width of the respective partial area in the second direction. At the edge of the respective partial area, a reversal of movement takes place with a (slight) lateral offset in the first direction before the processing beams are moved in the opposite direction in the first direction across the entire width of the respective partial area. In the event that several processing beams are positioned in one and the same partial area, it may be sufficient - i.e. if the partial area is suitably dimensioned - if the processing beams are moved only once in the second direction over the partial area in order to melt it completely.

In a further variant, a gas stream is guided over the powder layer, the flow direction of which is preferably at least partially directed against the direction of movement of the processing beams in the processing plane and/or the order of irradiation of the sub-areas preferably takes place depending on the distance of the respective sub-areas in the flow direction from a supply device for providing the gas stream. The gas stream can, for example, be a protective gas stream in order to protect optical components of the irradiation device, for example a window, from contamination, for example from soot particles, which form when the powder material is irradiated. It has proven to be advantageous if the movement, or more precisely the direction of movement, of the processing beams during exposure does not coincide with the flow direction of the protective gas stream, since the protective gas stream removes soot particles which in this case would be deposited and welded onto the irradiated powder layer directly in front of the processing beam(s).

To counteract this problem, the sub-areas can be irradiated in a sequence in which the sub-area(s) furthest away from the supply device in the direction of flow of the gas flow are irradiated first. Preferably, it is taken into account that two sub-areas directly next to each other are generally not irradiated one after the other. In particular, the directions of movement of the processing beams in all irradiated sub-areas in the processing plane assume the same angle to the direction of flow of the gas flow.

In the event that the second direction along which the exposure takes place runs parallel or approximately parallel to the shielding gas flow, the movement of the processing beams along the second direction, e.g. the Y direction, can only take place with one orientation (positive or negative Y direction). For example, in the event that the flow direction of the shielding gas flow runs in the negative Y direction, the processing beams can only be moved in the positive Y direction, as is the case, for example, in the WO 2014/125280 A1 in detail, which is incorporated by reference into the content of this application.

In a further variant, the positions of the at least two processing beams in the first direction are spaced apart from one another by a distance that essentially corresponds to an integer multiple (typically different from one) of the extent of a respective partial area in the first direction. As described above, it has proven to be advantageous if, when exposing a contiguous surface area, the required laser power is introduced in the form of self-contained rhomboid, for example diamond-shaped, square or rectangular partial areas. The parallel exposure of two immediately adjacent partial areas has proven to be rather unfavorable with regard to the heat balance of the melt, but is also possible or useful in certain cases. For the parallel irradiation of two partial areas, it has proven to be advantageous if a gap of at least one partial area is formed between the partial areas simultaneously irradiated with the two or more processing beams. Before irradiating the other sub-areas that form the gaps between the irradiated sub-areas, other sub-areas of the connected surface area are usually irradiated, which are also offset in the second direction from the already irradiated sub-areas. Ideally, the distance between the positions of the Processing beams are spaced apart from each other by exactly an integer multiple (other than one), in particular an even-numbered integer multiple, for example exactly twice or exactly four times, but possibly also a non-even-numbered multiple, for example three times, five times... the extent of a respective sub-area. As described above, depending on the position of the processing beams in the processing plane in the first direction, there may be an undesirable partial overlap of the sub-areas. For the purposes of this application, a distance that essentially corresponds to an integer multiple of the extent of a respective sub-area in the first direction is understood to mean a distance that deviates by +/- 10% from the extent (edge length) of a respective sub-area in the first direction.

The geometry or the area of the respective sub-areas that form the connected surface area is usually the same size. However, it is also possible for the connected surface area to have several types of, for example, rectangular sub-areas that differ in their surface area, for example in their width and/or length. In this case, the lengths and/or widths of the respective sub-areas can each have an integer ratio to one another, so that two or more of the sub-areas complement each other to form a larger sub-area. The use of smaller sub-areas can be advantageous, particularly at the edge of the connected surface area, in order to adapt it as well as possible to the surrounding edge contour.

In a further variant, a difference angle between the at least two processing beams in the first direction when aligning the at least two processing beams to different positions in the processing plane, the distance in the processing plane of which varies depending on the location depending on a deflection angle of the scanner device, is selected such that either adjacent sub-areas in the middle of the processing area adjoin one another in the first direction or adjacent sub-areas at the edge of the processing area adjoin one another in the first direction. In order to align the two processing beams to different positions in the processing plane, it is necessary for them to emerge from the scanner device at a (slightly) different angle, which is measured in a deflection plane that runs along the first direction.

In the middle of the processing area, one of the processing beams is aligned perpendicular to the processing plane, which corresponds to a deflection angle of 0°. At the edge of the processing area, one of the processing beams is aligned at a deflection angle of, for example, approx. 20°, which corresponds to the maximum possible deflection angle by the scanner device. When, for example, two processing beams are deflected, the distance between the (focus) positions of the two processing beams changes depending on the deflection angle and thus on the positions of the processing beams in the processing plane in the first direction. The distance or offset between the (focus) positions and thus between the two simultaneously irradiated partial areas becomes greater the further the processing beams in the deflection plane are pivoted towards the edge of the processing area. With a fixed difference angle between the two processing beams, the offset or the distance between the two processing beams at the edge of the processing area can be set in such a way that two adjacent partial areas touch each other after exposure or are immediately adjacent to each other. When swiveling inwards, the overlap factor between adjacent exposed partial areas increases continuously, i.e. two adjacent partial areas and also the individual tracks overlap more in the middle of the processing area than at the edge of the processing area. In the irradiation process, this means a reduction in effectiveness towards the middle of the processing area, since the trailing processing beam deflected at a larger deflection angle exposes part of an already exposed partial area a second time, i.e. the two partial areas partially overlap in the middle of the processing area (usually by no more than approx. 10% of the respective extension of the partial areas). As described above, typically two adjacent sub-areas are not irradiated simultaneously, but rather there is a gap of at least one sub-area between the irradiated sub-areas. The difference angle is therefore typically chosen so that a corresponding gap remains between the two simultaneously irradiated sub-areas, which corresponds exactly to the width of one (or possibly several) sub-areas in the middle of the processing area.

Alternatively, the difference angle can be set in such a way that in the zero position, i.e. in the middle of the processing area, there is no lateral offset between adjacent sub-areas in the first direction, i.e. that they are directly adjacent to each other in the middle of the processing area. This lateral offset or distance increases when the two processing beams are swiveled with increasing deflection angle and can be selected in such a way that two adjacent sub-areas at the edge of the processing area are slightly spaced apart from each other. This makes it possible to take advantage of the fact that the actual (focus) positions of the processing beams in the entire processing area can be measured and are therefore known by means of suitable online calibration. The variable offset dimension or the distance between two of the exposed partial areas in the first direction at the edge or near the edge of the processing area is therefore also known and can be exposed or compensated for in parallel with the generation of the partial areas with another processing beam or subsequently with a single processing beam, for example with the primary processing beam, in order to form the connected surface area.

If necessary, the difference angle or the difference angles between the at least two processing beams that serve to expose different partial areas can be varied depending on the deflection angles or the position of the (focus) positions in the first direction in the processing area. For this purpose, for example, a (fast) beam splitter device can be used to split the primary processing beam into the at least two processing beams, which enables the difference angle to be adjusted. For this purpose, the beam splitter device can, for example, have differently designed beam splitter elements that can be optionally introduced into the beam path of the primary processing beam, for example wedge plates with different wedge angles (see below).

As an alternative to varying the difference angle, a preferably telecentric F-Theta lens can be used to focus the processing beams (and possibly other processing beams) in the processing plane. When using a telecentric lens, the processing beams are always aligned perpendicular to the processing plane, so that there is almost no location-dependent variation in the distance between the processing beams in the processing plane.

In a further variant, the positions of the processing beams or the further processing beams in the further sub-area or in the at least two further sub-areas are offset from one another in a second direction, and the simultaneous change in the positions of the at least two processing beams or the at least two further processing beams in the further sub-area or in the at least two further sub-areas comprises a simultaneous movement of the processing beams or the further processing beams in a first direction, preferably perpendicular to the second direction. It can be advantageous if some (first) sub-areas are scanned along the first direction, while other (second) sub-areas are possibly scanned simultaneously along a second direction perpendicular to the first.

In the case of a continuous surface area which is divided into rhomboidal, for example diamond-shaped, square or rectangular sub-areas in the manner of a chessboard, the "white" sub-areas can, for example, be scanned in the first direction, while the "black" sub-areas are scanned in the second direction, or vice versa. For this purpose, one and the same primary processing beam can be split first in the first direction and then in the second direction using two different beam splitter devices which can optionally be introduced into the beam path. If necessary, one and the same beam splitter device can be used for this purpose, which is rotated by 90° about an axis of rotation which runs along the beam direction of the primary processing beam. For example, a beam splitter device in the form of a diffractive optical element can be used to split the primary processing beam or the further primary processing beam into several sub-beams.

In a further development, the method additionally comprises: splitting a further primary processing beam between the at least two further processing beams, and guiding the at least two further processing beams to a further common scanner device for aligning the at least two further processing beams to different positions in the processing plane. To irradiate the further partial areas, a further primary processing beam can be used, which is split between two or more, for example five or more, further processing beams. As explained above, the further processing beams can be used to irradiate the "black" partial areas that are scanned in the second direction, while the processing beams into which the primary processing beam is split can be used to irradiate the "white" partial areas, or vice versa. In particular, it has proven to be advantageous in this case if the two or more processing beams are used to simultaneously irradiate one and the same partial area, for example by moving two or more parallel processing beams across the entire width of the respective partial area before a reversal of direction takes place and the two or more processing beams are moved in opposite directions.

In this variant, too, a (non-split) processing beam can be used to process those areas of a layer of the three-dimensional component that are unsuitable for irradiation by the split processing beams. For example, this can be the (edge) contour(s) of the layer of the three-dimensional component or the edge area between the connected surface area and the edge contour or, in principle, all areas that are too narrow or too misshapen for irradiation with two or more processing beams moving parallel across the processing plane.

In another variant, a focus position correction is carried out to correct the focus positions of the processing beams in the beam path of the primary processing beam. The focus positions of the at least two processing beams along their respective beam direction should ideally be in the processing plane. Due to the deflection using the scanner mirror (without using an F-Theta lens), the focus positions of the processing beams are on a spherical surface when the scanner mirror(s) are pivoted, i.e. not exactly in the processing plane. In order to compensate for the variation in the focus position (perpendicular to the processing plane) across the processing area, a focus position correction can be carried out, which corrects the spherical deviation of the scanner field, for example by rapid compensating movements of a lens arranged in the beam path of the primary processing beam, which is moved in the beam direction of the primary processing beam, resulting in a rapid focus position shift. The movable or displaceable lens can, for example, be arranged in a focus position correction device or optics. Due to the comparatively small difference angle between the processing beams, it is sufficient to carry out the focus position correction for the primary processing beam, i.e. an individual focus position correction for each of the processing beams can be dispensed with.

In terms of control technology, the center of gravity or the mean value of the positions of the processing beams in the processing plane can be used for the path control for the focus position correction or in general, i.e. the mean value is used as the movement path of the (primary) processing beam. In this case, the control can be carried out (essentially) in such a way as if only the primary processing beam were used for the irradiation. In particular, the center of gravity path can be used as a specification for determining the focus position correction.

The invention also relates to an irradiation device of the type mentioned at the outset, which has a control device which is designed or programmed to simultaneously change the positions of the at least two processing beams in a partial area or in at least two partial areas of a continuous surface area which is divided into a plurality of preferably rhomboid, in particular diamond-shaped, rectangular or square partial areas for the irradiation, until the powder layer in the partial area or in the at least two partial areas has completely melted, and which is designed to simultaneously change the positions of the at least two processing beams or of at least two further processing beams in a further partial area or in at least two different further partial areas of the continuous surface area until the powder layer in the further partial area or in the at least two further partial areas has completely melted.

The control device is thus designed or programmed to carry out the method described above for generating the connected surface area. The control device can also be designed or programmed accordingly to carry out the variants of the method described above. The control device acts on the scanner device, or more precisely on the two scanner mirrors of the scanner device, for the simultaneous change in the positions of the (further) processing beams.

In one embodiment, the irradiation device has a further beam splitter device for splitting a further primary processing beam, in particular a further laser beam, into at least two further processing beams, in particular into at least two further laser beams, as well as a further scanner device for aligning the at least two further processing beams to different positions in the processing plane.

The irradiation device can, for example, have two identically constructed scanner devices that are arranged in such a way that their scanning areas or their processing fields overlap in the processing plane. Using the additional processing beams, the “black” or “white” sub-areas of a checkerboard-like, connected surface area can be irradiated, for example, in the manner described above. As described above Such a checkerboard-like surface area does not necessarily have to have square sub-areas, but can have rhomboidal, in particular diamond-shaped, rectangular or square sub-areas, for example. In particular, the further beam splitter device can be designed to split the further primary processing beam in the second direction, so that the further processing beams are aligned to different positions in the processing plane in the second direction, while the beam splitter device is designed to split the primary processing beam in a first direction, so that the processing beams are aligned to different positions in the first direction, preferably perpendicular to the second direction.

In one embodiment, the beam splitter device is designed to split the primary processing beam into the at least two processing beams by splitting a beam cross-section of the primary processing beam. In this case, the beam splitting is therefore not carried out by a polarization beam splitter, in which the entire beam cross-section is usually split into two mutually perpendicular polarization components. The splitting of the primary processing beam into the at least two processing beams has proven to be advantageous in particular in the collimated beam path of the primary processing beam, so that the beam splitter device is preferably arranged in the collimated beam path of the primary processing beam. For the splitting of the beam cross-section, it is advantageous if the processing beams generated by the splitting are each aligned at an angle to one another, which is typically maintained when the processing beams are deflected at the scanner device. Alternatively or additionally, it is also possible to offset the processing beams laterally from one another when splitting at the beam splitter device.

In a further development, the beam splitter device is designed to split the primary processing beam by deflecting at least a portion of the beam cross-section of the primary processing beam (preferably at a differential angle to the beam direction of the primary processing beam). In this case, the beam splitter device can be used, for example, to deflect half of the beam cross-section - and thus half of the power - of the processing beam by the beam splitter device covering only half of the beam profile.

In a further development, the beam splitter device is designed as a wedge plate that is transparent to the primary processing beam. The wedge plate can be used to deflect a partial area of the beam cross-section at a differential angle that is generally maintained up to the processing plane. The wedge angle of the wedge plate determines the differential angle for a given refractive index of the transparent material of the wedge plate, e.g. quartz glass. The wedge angle can in particular be set such that the distance between the positions of the at least two processing beams in the processing plane corresponds to an integer multiple of the edge length of an irradiated partial area. The wedge angle is preferably set such that the distance between the positions corresponds to twice or three times the edge length of a respective partial area in the first direction, so that during irradiation a gap of one or two partial areas remains between the simultaneously irradiated partial areas. The wedge plate is ideally arranged in the collimated beam path of the primary processing beam after any expansion and before focusing, i.e. focusing does not take place on the primary processing beam, but on the at least two processing beams after division.

In a further, alternative development, the beam splitter device is designed as a diffractive optical element, for example as a diffraction grating or the like. The diffractive optical element can be used in particular to split the primary processing beam into several processing beams, which ideally have identical properties and only differ in the respective angles at which they impinge on the scanner device. From a primary laser beam, which has, for example, 500 W power and a focus diameter in the processing plane of approx. 100 µm, the diffractive optical element can, for example, generate five laser beams, each with a power of 100 W and a diameter of also 100 µm. If the five processing beams are moved next to one another and in parallel within an irradiated partial area, a strip or an area with a width of approx. 500 µm is melted. In this way, five times as much material can be melted in the same amount of time as with the primary processing beam, which only has a diameter of 100 µm.

In a further embodiment, the irradiation device comprises a movement device for at least partially moving the beam splitter device into the beam cross-section of the primary processing beam and out of the beam cross-section of the primary processing beam. As described above, the wedge plate can be introduced into the beam path of the primary processing beam in such a way that it only covers half the beam cross-section. For the rapid movement of the wedge plate into and out of the beam path, the movement device can in particular carry out a rotational or pivoting movement of the wedge plate about a rotational axis. For this purpose, the movement device can be designed, for example, as a fast so-called wedge switch, as is used for coupling into a 2 in 1 fiber. The movement device can be designed to move a respective diffractive optical element into and out of the beam path of the primary processing beam with a linear movement and/or with a rotational movement. The control device described above can also be used to control the movement device.

In a further embodiment, the irradiation device has a focus position correction device for correcting the focus positions of the processing beams, which is arranged in the beam path of the primary processing beam. As described above, due to the comparatively small difference angle(s) of the processing beams, the focus position correction, which depends on the position in the processing plane, can be carried out in the primary processing beam. A so-called varioSCAN focusing device, such as that offered by Scanlab GmbH, can be used as the focus position correction device.

In a further embodiment, the irradiation device has a preferably telecentric F-theta lens for focusing the processing beams in the processing plane. An F-theta lens is a special type of lens that is used for scanner applications. In contrast to an imaging (camera) lens, an F-theta lens produces a desired linear distortion in order to fulfill the F-theta condition f * θ = X, where X is the distance from the center of the processing field in the processing plane, f is the focal length of the F-theta lens and θ is the angle at which the respective processing beam in the entrance pupil plane of the F-theta lens is aligned to the optical axis of the F-theta lens.

The F-Theta lens can reduce the location-dependent variation in the distance between the processing beams in the processing plane, which depends on the deflection angle of the scanner device. When using a telecentric F-Theta lens or a telecentric lens in general, the processing beams (essentially) always hit the processing field perpendicularly, regardless of the deflection angle and thus regardless of the location in the processing field, so that there is practically no location-dependent variation in the distance between the processing beams in the processing plane.

It is understood that the irradiation device described above or a processing machine comprising the irradiation device can have at least one beam source, in particular at least one laser source, for generating the at least one primary processing beam or the primary laser beam. In particular, laser sources can be used which have a power in the range of more than 100 W.

A further aspect relates to a processing machine for producing three-dimensional components by irradiating powder layers, comprising: an irradiation device as described above, and a processing chamber with a processing plane in which the powder layer to be irradiated can be arranged. The processing machine can, for example, be designed as in the EP 3 023 228 A1 described, which is incorporated in its entirety by reference into this application. A production space is provided in the processing chamber, in which a work surface is typically arranged at the level of the processing plane. The processing area of the irradiation device is formed in a part of the working surface in which a construction platform area is provided for providing a powder bed, the topmost powder layer of which lies in the processing plane. A powder reservoir area with a powder storage container can be provided in the processing chamber for providing the powder. A sliding device arranged in the processing chamber can serve to transfer the powder from the powder storage container to the construction platform area.

In one embodiment, the processing machine has a supply device for providing a gas flow which flows over the processing plane in a construction platform area provided for providing a powder bed, and whose flow direction is preferably at least partially directed against the direction of movement of the processing beams and/or in which the control device is designed to determine the order of irradiation of the partial areas depending on the distance of the respective partial areas in the flow direction from a supply device for providing the gas flow. The gas flow can be as in the above-cited EP 3 023 228 A1 to remove smoke from the processing chamber. The gas system used to provide the gas flow can be playing style as in the EP 3 023 228 A1 To ensure that the movement of the processing beams is at least partially directed against the flow direction of the gas stream, the irradiation can be directed, for example, to the direction described in the WO 2014/125280 A1 described above, even if this slows down the irradiation.

Further advantages of the invention emerge from the description and the drawing. Likewise, the features mentioned above and those listed below can be used individually or in combination in any desired way. The embodiments shown and described are not to be understood as an exhaustive list, but rather are exemplary in nature for the description of the invention.

• 1a eine schematische Darstellung einer Bestrahlungseinrichtung mit einer Strahlteilereinrichtung zur Aufteilung eines primären Bearbeitungsstrahls in zwei Bearbeitungsstrahlen, die auf unterschiedliche Positionen in einer Bearbeitungsebene ausgerichtet werden,
• 1b ein Detail der Strahlteilereinrichtung in Form einer Keilplatte zur Umlenkung der Hälfte des Strahlquerschnitts des primären Bearbeitungsstrahls,
• 2 eine schematische Darstellung einer Bearbeitungsmaschine zum Herstellen von dreidimensionalen Bauteilen durch Bestrahlen von Pulverschichten mit der Bestrahlungseinrichtung gemäß 1a,
• 3a,b schematische Darstellungen von Teilbereichen eines zusammenhängenden Flächenbereichs in der Mitte und am Rand eines Bearbeitungsbereichs einer Scannereinrichtung,
• 4 eine schematische Darstellung einer Bearbeitungsmaschine mit einer Bestrahlungseinrichtung mit drei Strahlquellen,
• 5a,b schematische Darstellungen der Bestrahlung eines kreisförmigen Flächenbereichs einer Schicht eines dreidimensionalen Bauteils mit der Bearbeitungsmaschine von 4, sowie
• 6 eine schematische Darstellung der Bestrahlung eines zusammenhängenden Flächenbereichs mit einer Mehrzahl von rhomboiden Teilbereichen.

They show:

• 1a a schematic representation of an irradiation device with a beam splitter device for splitting a primary processing beam into two processing beams which are aligned to different positions in a processing plane,
• 1b a detail of the beam splitter device in the form of a wedge plate for deflecting half of the beam cross-section of the primary processing beam,
• 2 a schematic representation of a processing machine for producing three-dimensional components by irradiating powder layers with the irradiation device according to 1a ,
• 3a ,b schematic representations of sub-areas of a contiguous surface area in the middle and at the edge of a processing area of a scanner device,
• 4 a schematic representation of a processing machine with an irradiation device with three beam sources,
• 5a ,b schematic representations of the irradiation of a circular surface area of a layer of a three-dimensional component with the processing machine of 4 , as well as
• 6 a schematic representation of the irradiation of a contiguous surface area with a plurality of rhomboid sub-areas.

1a shows an irradiation device 1 for a 1a processing machine not shown. The irradiation device 1 is used to irradiate a continuous surface area 2 of a powder layer 3, which is rectangular in the example shown. For the irradiation, the irradiation device 1 is connected to a 1 A primary processing beam 4 in the form of a laser beam is fed to the irradiation device 1 from a beam source (not shown in the picture) in the form of a laser source. The irradiation device 1 has a scanner device 5 with two rotatable scanner mirrors 6a, 6b (galvano mirrors) which serve to deflect the primary processing beam 4 or two processing beams 4a, 4b into which the processing beam 4 is split at a beam splitter device in the form of a transparent wedge plate 7. The wedge plate 7 can be moved into the beam cross section A of the primary processing beam 4, which is circular in the example shown, and also out of the beam cross section A of the primary processing beam 4 again with the aid of a movement device 8. In the case of the 1a In the example shown, the wedge plate 7 is only partially moved into the beam cross-section A of the primary processing beam 4, namely until it covers half A / 2 of the beam cross-section A, as shown in 1b can be seen. In this way, the power of the primary processing beam 4 is divided equally between the two processing beams 4a, 4b.

The wedge plate 7 has a wedge angle γ, which causes the second processing beam 4b to be deflected at a differential angle δ relative to the first processing beam 4a (and relative to the primary processing beam 4). The differential angle δ depends on the wedge angle γ and the refractive index of the material of the wedge plate 7 in a manner known to those skilled in the art. The differential angle δ is maintained during the double deflection or reflection of the processing beams 4a, 4b on the two scanner mirrors 6a, 6b of the scanner device 5, so that the two processing beams 4a, 4b strike the powder layer 3 at different positions P1, P2 in the connected surface area 2. In the example shown, the difference angle δ runs in the XZ plane of an XYZ coordinate system, i.e. the two positions P1, P2 of the two processing beams 4a, 4b are spaced apart from each other by a distance 2 L in a first direction, which is referred to below as the X direction. The distance 2 L of the positions P1, P2 of the two processing beams 4a, 4b on the powder layer 3 depends not only on the difference angle δ but also on the (known) distance of the processing plane E from the irradiation device 1 or from the scanner device 5. In the example shown, the processing plane E lies in the XY plane of the XYZ coordinate system.

In the example shown, the movement device 8 is designed to rotate the wedge plate 7 about a parallel to the beam direction of the primary processing beam 4. It has been found that with the aid of a rotary movement the wedge plate 7 can be moved particularly quickly into the beam cross-section A of the primary processing beam 4 and out of it again. This is advantageous in order to enable the fastest possible switching between irradiation of the powder layer 3 with the primary processing beam 4 and irradiation of the powder layer 3 with the two processing beams 4a, 4b.

As in 1a As can also be seen, a (static) focusing device 9 in the form of a focusing lens is arranged in the beam path of the two processing beams 4a, 4b after the beam splitter device 7 in order to focus the processing beams 4a, 4b in the processing plane E. A focus position correction device 10 is arranged in the beam path of the primary processing beam 4, which serves for the (dynamic) correction of the focus positions F1, F2 of the two processing beams 4a, 4b (in the beam direction) in order to ensure that the focus positions F1, F2 as in 1a shown are in the processing plane E. The focus position correction device 10 is required because the processing beams 4a, 4b focused by the focusing lens 9 and deflected by the scanner device 5 would be focused in a spherical shell and not in the processing plane E as desired. The focus position correction device 10 is arranged in the primary processing beam 4 because the positions P1, P2 of the processing beams 4a, 4b in the processing plane E have a comparatively small distance 2 L, which is typically less than approx. 1.0 mm, so that an individual focus position correction of the two processing beams 4a, 4b can be dispensed with. A so-called varioSCAN focusing device, such as that sold by Scanlab GmbH, can serve as the focus position correction device 10.

The in 1a The contiguous surface area 2 shown is surrounded by an edge contour 11, which corresponds to the outer contour of a layer of the three-dimensional component that is to be produced when the powder layer 3 is irradiated. To produce the three-dimensional component, the entire area within the edge contour 11 is to be irradiated. In the example shown, the area within the edge contour 11 is divided into the contiguous surface area 2, which is irradiated using the two processing beams 4a, 4b, and into an edge area 12, which is formed between the contiguous surface area 2 and the edge contour 11. The contiguous surface area 2 is irradiated simultaneously using the two processing beams 4a, 4b, as described in more detail below. The edge region 12 and the edge contour 11, however, are irradiated with the primary processing beam 4, for which purpose the beam splitter device 7 is removed from the beam path of the primary processing beam 4 with the aid of the movement device 8.

The rectangular contiguous surface area 2 shown in the example is divided into a plurality of square sub-areas for irradiation, namely into a total of eight sub-areas in the longitudinal direction (X direction) and into three sub-areas in the transverse direction (Y direction) of the contiguous surface area 2, of which six sub-areas T1 to T6 are in 1a The sub-areas T1, T2, ... have a length L in the X direction, which can be 1.0 mm, for example, and an identical length in the Y direction. Unlike in 1a As shown, the sub-areas T1, T2, ... can have a different geometry, e.g. rectangular. It is also possible for the sub-areas T1, T2, ... to have a different geometry, e.g. rhomboid, diamond-shaped or basically any geometry, as long as they are arranged in a regular arrangement in the manner of a grid or matrix.

As in 1a As can also be seen, the two processing beams 4a, 4b, which are offset from one another in the X direction in the processing plane E, are used to simultaneously irradiate two square partial areas T3, T4 of the connected surface area 2, between which a gap is formed which has exactly the size of a partial area T1 to T6. As described above, the positions P1, P2 of the two processing beams 4a, 4b in the processing plane E have a distance 2 L from one another, ie a distance which corresponds to twice the length L of a respective partial area T1 to T6. The simultaneous irradiation of two partial areas T3, T4, which are not arranged directly adjacent, has proven to be advantageous with regard to the heat balance of the melt of the powder layer 3. Unlike in 1a As shown, the distance between the two processing beams 4a, 4b in the X direction can correspond to another integer multiple, for example four times, the length L of a respective sub-area T1 to T6. The number of sub-areas into which the contiguous surface area 2 is divided in the X direction should be divisible by the integer multiple of the length L of a respective sub-area T1 to T6. This is generally possible since the length L of the sub-areas T1 to T6 can be freely selected within certain limits.

For the irradiation of the two partial areas T3, T4, the positions P1, P2 of the two processing beams 4a, 4b in the processing plane E is changed simultaneously with the aid of the scanner device 5 until the powder layer 3 in the two partial areas T3, T4 has completely melted. In the example shown, when the positions P1, P2 of the two processing beams 4a, 4b are changed simultaneously, the two processing beams 4a, 4b are moved in a scanning movement over the entire edge length L of the partial areas T3, T4 in the Y direction. At the edge of the respective partial area T3, T4, a reversal of movement takes place, in which the two processing beams 4a, 4b are slightly offset in the X direction in order to travel along an adjacent path or track in the Y direction in a scanning movement. The movement of the two processing beams is then reversed again in the X direction. This process is repeated until the two partial areas T3, T4 have been completely melted, i.e. over their entire surface.

After irradiating the third and fourth partial areas T3, T4, two further partial areas, namely the fifth and sixth partial areas T5, T6, are irradiated by means of the two processing beams 4a, 4b. For this purpose, the two processing beams 4a, 4b are first moved in the fifth and sixth partial areas T5, T6, i.e. their positions P1, P2 in the processing plane E are suitably changed. When repositioning the two processing beams 4a, 4b, they are typically switched off by 1a beam source (not shown) is deactivated for a short time. If necessary, the positions P1, P2 of the two processing beams 4a, 4b at the end of the irradiation of the third and fourth partial areas T3, T4 can be selected so that they are positioned in a corner of the third or fourth partial area T3, T4, which also forms a corner of the fifth and sixth partial areas T5, T6. In this case, the irradiation of the fifth and sixth partial areas T5, T6 can follow immediately on from the irradiation of the third and fourth partial areas T3, T4. The irradiation of the fifth and sixth partial areas T5, T6 takes place as described above, i.e. by simultaneously changing the positions P1, P2 of the two processing beams 4a, 4b in the fifth and sixth partial areas T5, T6 until they are completely melted. The remaining partial areas of the connected surface area 2 are also irradiated accordingly, for example the first and second in 1a shown partial area T1, T2, until the entire contiguous surface area 2 is irradiated.

If necessary, those sub-areas which form the gaps between the first and second sub-areas T1, T2, the third and fourth sub-areas T4, T5, the fifth and sixth sub-areas T5, T6, etc. in the connected surface area 2 can be processed using the two processing beams 4a, 4b by moving them simultaneously in the Y direction and not in the X direction. For this purpose, the irradiation device 1 can have a further beam splitter device, for example in the form of a further wedge plate rotated by 90°, in order to divide the primary processing beam 4 into two processing beams 4a, 4b, the positions P1, P2 of which are offset in the Y direction in the processing plane E.

In a subsequent or preceding step, the edge region 12 and the edge contour 11 can be irradiated with the primary processing beam 4 in order to completely irradiate the area located within the edge contour 11. In the example shown, the coordination of the movements of the scanner mirrors 6a, 6b and the beam splitter device 7 takes place by means of a 2 illustrated control device 14 of the irradiation device 1.

The orientation of the X-direction and the Y-direction in the processing plane E is basically arbitrary. In the example shown, the positive Y-direction corresponds to the flow direction of a protective gas flow 13 which is guided over the powder layer 3. The protective gas flow 13 is guided in a processing chamber 16 of a 2 The powder layer 3 is guided by the processing machine 15 shown, which forms the uppermost layer of a powder bed 19 in which a three-dimensional component 20, or more precisely the already produced layers of the three-dimensional component 20, are embedded. The powder bed 19 is formed in a construction platform area 17, which has, for example, a cylindrical construction platform with a stamp, on the upper side of which the processing plane E is formed, which is irradiated by the irradiation device 1 in the manner described above. The processing machine 15 also has a beam source 23 in the form of a laser source for generating the primary processing beam 4.

The processing machine 15 also has a supply device 21 for the provision of the protective gas flow 13, which in 1a As an alternative to providing a protective gas flow 13 which has a flow direction in the positive Y direction, the protective gas flow 13 can have a flow direction in the positive or negative X direction or can be oriented in another way. The protective gas flow 13 is guided over the construction platform area 17 in order to keep smoke away from the irradiation device 1 arranged above it, for example from a window formed there. The supply device 21 can, for example, be designed as in the above-cited EP 3 023 228 A1 To ensure that the flow direction of the protection gas flow 13 (here: positive Y-direction) is at least partially directed against the direction of movement of the processing beams 4a, 4b in the processing plane E, can be achieved with a synchronous movement of the processing beams 4a, 4b in the Y-direction, as shown in 1a As shown, the exposure of the sub-areas T1 to T6 can be carried out by moving the processing beams 4a, 4b only in the negative Y direction synchronously over the jointly exposed sub-areas T1, T2; T3, T4; T5, T6, ie the opposite movement in the positive Y direction is omitted, as in the above-cited WO 2014/125280 A1 It is also possible to select the order of irradiation of the sub-areas T1, T2, ... depending on the distance of the respective sub-area T1, T2, ... in the flow direction +Y from the provision device 21. In this case, in particular sub-areas T1, T2, ... that are at a greater distance from the provision device 21 in the flow direction +Y can be irradiated before sub-areas T1, T2, ... that are at a smaller distance from the provision device 21 in the flow direction +Y.

To produce a new layer of the three-dimensional component 20, powder is first taken from a powder reservoir container 22 arranged in the processing chamber 16 and is transferred from a powder reservoir area 18 in which the powder reservoir container 22 is located to the construction platform area 17. In the example shown, a sliding device (not shown in detail) is used for this purpose, which transfers the powder from the powder reservoir area 18 to the construction platform area 17 by moving the powder on the upper side of a work surface located in the processing plane E. The stamp in the construction platform area 17 and thus the powder bed 19 is moved downwards in parallel by the layer thickness of a powder layer, as in 2 indicated by an arrow before the irradiation of the (new) powder layer 3 in the build platform area 17 is carried out.

A processing area B for carrying out the irradiation of the powder layer 3 is laterally delimited by the construction cylinder of the construction platform area 17. The dimensions of the processing area B, which can be approximately 30 cm, for example, are adapted to the (maximum) deflection angle α of the primary processing beam 4 by the scanner device 5, i.e. the scanner mirrors 6a, 6b can be rotated about their respective axes of rotation so far that every location of the processing area B in the processing plane E can be reached.

As in 3a ,b, the distance between the two positions P1, P2 in the machining plane E depends on the 2 The deflection angle α of the scanner device 5 for the two processing beams 4a, 4b depends on the position of the processing area B at which the two processing beams 4a, 4b meet the processing plane E. As in both 3a as well as in 3b As can be seen, the distance between the two processing beams 4a, 4b increases continuously from the center M of the processing area B to the lateral edge of the processing area B. Accordingly, the distance between two partial areas T1, T2, which are generated by the two processing beams 4a, 4b, depends on the X coordinate along the processing area B.

The difference angle δ between the two processing beams 4a, 4b in the X direction can be adjusted by selecting the wedge angle γ of the wedge plate 7. 3a shows the two processing beams 4a, 4b at a first difference angle δ ₁ , at which the two partial areas T1, T2 directly adjoin one another at the edge R of the processing area B, while they slightly overlap in the X direction in the middle M of the processing area B, generally by a proportion of the length L of the respective partial area T1, T2, which is not more than approximately 10%. 3b shows the two processing beams 4a, 4b at a second, slightly larger difference angle δ ₂ , at which the two partial areas T1, T2 are directly adjacent to one another in the middle M of the processing area B, while the two partial areas T1, T2 are slightly spaced apart from one another at the edge of the processing area B, for example by approximately 1 mm.

In the 3a At the first difference angle δ ₁ shown, the irradiation in the middle M of the processing area B is less effective because the partial areas T1, T2 overlap and in the overlap area a double irradiation of the powder layer 3 takes place. 3b At the difference angle δ ₂ shown, the two partial areas T1, T2 do not overlap in the middle M of the processing area B, but additional irradiation with the primary processing beam 4 is usually required in order to also irradiate the gap between the two partial areas T1, T2 at the edge R of the processing area B. The problem described above can be avoided if the processing beams 4a, 4b are used to simultaneously irradiate one and the same partial area T1 or T2, as described below.

4 shows a processing machine 15, which differs from the one in 2 shown processing machine 15 essentially by the design of the irradiation device 1, as well as by the fact that the processing machine 15 is has three beam sources 23, 23a, 23b instead of a single beam source 23. The first beam source 23 generates a first primary processing beam 4, which in the example shown is split at a beam splitter device in the form of a diffractive optical element 24 (diffraction grating) into five processing beams 4a-e, which are aligned onto the processing plane E or deflected in the direction of the processing plane E via a scanner device 5. The second beam source 23a generates a further (second) primary processing beam 25, which is split at a further (second) beam splitter device 24a, which is also designed as a diffractive optical element, into five further processing beams 25a-e, which are aligned onto the processing plane E via a further scanner device 25b. The third beam source 23b generates a further (third) primary processing beam 26, which is aligned to the processing plane E via a third scanner device 5b. The representation of further optical elements of the irradiation device 1, which, for example, as in the case of the 1a shown irradiation device 1 can be designed, was in 4 omitted for reasons of clarity.

As with the 2 The example shown can also be used in the 4 In the irradiation device 1 shown, the two beam splitter devices in the form of the diffractive optical elements 24, 24a are moved into and out of the beam path of the primary processing beam 4 or the further primary processing beam 4a, for which purpose corresponding movement devices 8, 8a are provided, which in the example shown enable a linear movement of the diffractive optical elements 24, 24a. As in 4 As is also indicated, the two beam splitter devices 24, 24a are arranged such that the division of the respective primary processing beams 4, 25 into the five processing beams 4a-e, 25a-e in two mutually perpendicular directions (X direction and Y direction), so that the positions P1 to P5 of the processing beams 4a-e in the processing plane E are spaced from one another in the X direction, while the positions P1 to P5 of the further processing beams 25a-e in the processing plane E are spaced from one another in the Y direction.

At the 4 In the irradiation device 1 shown, a telecentric F-theta lens 27 is used to focus the processing beams 4a-e, the further processing beams 25a-e and the (third) primary processing beam 26 in the processing plane E. Due to the telecentricity, the processing beams 4a-e, the further processing beams 25a-e and the primary processing beam 26 always impinge perpendicularly on the processing plane E, regardless of the location on the processing field, so that in the 4 There is practically no location-dependent variation in the distances between the positions P1 to P5, ... in the irradiation device 1 shown. It is understood that a (telecentric) F-Theta lens 27 also in the 1a irradiation device shown can be used.

For the complete irradiation of a surface of a cylindrical three-dimensional component 20 surrounded by a circular edge contour 11 in the example shown, irradiation can be carried out in which only the three primary processing beams 4, 25, 26 are used, as shown in 5a In this example, the area delimited by the circular edge contour 11 is divided into square sub-areas T or sub-areas T delimited at the edge of the circular area by the circular edge contour 11. Each of the sub-areas T is irradiated with one of the three primary processing beams 4, 25, 26 until the corresponding sub-area T is completely melted. In 5a The three processing beams 4, 25, 26, or more precisely their movement in the sub-areas T, are indicated by differently dashed arrows. The sub-areas T are scanned in a scanning movement, as described above in connection with 1a The assignment of the three primary processing beams 4, 25, 26 to the sub-areas T is basically arbitrary. One and the same processing beam 4, 25, 26 can also travel over some of the sub-areas T with a scanning movement in the Y direction, while other sub-areas T are traveled over with a scanning movement in the X direction, etc.

At the 5b The irradiation of the area formed within the circular edge contour 11 shown in FIG. 1 is - unlike in 5a is shown - firstly a coherent surface area 2 is defined, which is irradiated by means of the divided processing beams 4a-e, 25a-e, as described in more detail below. The edge area 12 located outside the coherent surface area 2 and the edge contour 11 are, however, irradiated by means of the third primary processing beam 26. In the example shown, the edge area 12 is divided into third sub-areas T3, which are irradiated one after the other by the third primary processing beam 26.

As in 5b As can be seen, the connected surface area 2 has twelve square sub-areas T1, T2 and four sub-areas T1, T2, which in one direction (X direction or Y direction) have only half the edge length of the square sub-areas T1, T2. For the irradiation, a respective first sub-area T1 is assigned the first (primary) processing beam 4 or the five (first) processing beams 4a-e, while the second primary processing beam 25 or the five (second) processing beams 25a-e are assigned to a respective second sub-area T2. As in connection with 4 As described above, the first primary processing beam 4 is divided into five processing beams 4a-e, whose positions P1 to P5 are spaced apart in the X direction. In contrast to the 1a In the example described, the five processing beams 4a-e are 5b In the example shown, the light is not radiated simultaneously onto different sub-areas T3, T4, but onto one and the same first sub-area T1, each offset in the X direction, as shown in 5b can be seen by the arrows. The five processing beams 4a-e are similar to the 5a In the example shown, the X-direction is moved parallel to the X-direction in a scanning movement in the Y-direction over the entire edge length of a respective first partial area T1. As described above in connection with 5a As shown, a reversal of movement with a lateral offset in the X direction occurs at the edge of each first partial area T1 before the five processing beams 4a-e are moved in opposite directions in the Y direction. The irradiation of the second partial areas T2 by means of the second processing beams 25a-e is carried out analogously to the irradiation of the first partial areas T1, with the difference that the X direction and the Y direction are swapped. As in 5b can also be seen, it may be sufficient if the small first partial areas T1 are irradiated in only a single scanning movement with the five processing beams 4a-e in order to completely melt them, ie in this case no reversal of movement is necessary. The same applies to the irradiation of the small second partial areas T2 with the second five processing beams 25a-e.

By dividing the two primary processing beams 4, 25 into the five processing beams 4a-e, 25a-e with the aid of the diffractive optical elements 24, 24a, the five processing beams 4a-e, 25a-e in the processing plane E each have approximately the same diameter as the two primary processing beams 4, 25. In this way, the width of the area covered by the processing beams 4a-e, 25a-e in one pass in the processing plane E can be increased by a factor of five, i.e., for example, from a width of 100 µm to a width of 500 µm. In this way, five times the area can be melted in the same time as with a respective primary processing beam 4, 25. It is understood that instead of five processing beams 4a-e, 25a-e, a larger or smaller number of processing beams can also be used to irradiate a respective first partial region T1 or a respective second partial region T2.

For the implementation of the related 5b The method described does not necessarily require an irradiation device 1 or a processing machine 15, as described in 4 Rather, a single primary processing beam 4 can also be used for this purpose, in whose beam path the first diffractive optical element 24 or the second diffractive optical element 24a can be introduced as desired in order to irradiate the first partial areas T1 or the second partial areas T2. In this case, the irradiation of the partial areas T1, T2 takes place sequentially, whereas in the case of the 4 shown processing machine 15, the irradiation of the first partial areas T1 and the second partial areas T2 can be carried out in parallel.

6 shows an example of a connected surface area 2 which does not have square but rhomboid, i.e. parallelogram-shaped sub-areas T1, T2. The length L of the sub-areas T1, T2 differs from the width B of the sub-areas in the example shown, but it is also possible that the length L and the width B of the sub-areas T1, T2 match, so that they are diamond-shaped. In the example shown, a respective first sub-area T1 is divided into the areas described above in connection with 5b described manner with two first processing beams 4a, 4b offset from each other in the X direction. Accordingly, a respective second partial area T2 is irradiated with the aid of two second processing beams 25a, 25b offset from each other in the Y direction, namely in the X' direction, which corresponds to the direction of the long outer edge of the rhomboid partial areas T1, T2. In the case of the 6 In the example shown, the movement of the second processing beams 25a, 25b over the second partial areas T2 thus takes place in a direction (X' direction) that is not perpendicular to the direction (Y direction) along which the first processing beams 4a, 4b are moved over the first partial areas T1. Preferably, in the partial areas T1, T2, the distance between the first processing beams 4a, 4b is kept as large as possible as the distance between the second processing beams 25a, 25b. If an equal distance is not possible due to unequal side lengths of the partial areas T1, T2, the distances between the first processing beams 4a, 4b and second processing beams 25a, 25b are kept as similar as possible.

It is understood that the irradiation of the respective sub-areas T1, T2, ... does not necessarily have to be carried out in a scanning movement, but but that the pattern used when irradiating a particular sub-area T1, T2, ... is basically arbitrary, even if the use of a scanning movement is usually advantageous.

Claims (20)

Method for producing a coherent surface area (2) of a three-dimensional component (20) by irradiating a powder layer (3) with at least two processing beams (4a,b; 4a-e), in particular with at least two laser beams, comprising: dividing a primary processing beam (4) into the at least two processing beams (4a,b; 4a-e), guiding the at least two processing beams (4a,b; 4a-e) to a common scanner device (5) for aligning the at least two processing beams (4a,b; 4a-e) via the same scanner mirror(s) (6a, 6b) to different positions (P1, P2; P1 to P5) in a processing plane (E) of the scanner device (5) in which the coherent surface area (2) is located, wherein the production of the coherent surface area (2), which is divided into a plurality of preferably rhomboid, in particular diamond-shaped, rectangular or square partial areas for the irradiation (T1 to T6; T1, T2) comprises: Simultaneous changing of the positions (P1, P2; P1 to P5) of the at least two processing beams (4a,b; 4a-e) in at least two different partial areas (T3, T4) of the connected surface area (2) until the powder layer (3) in the at least two partial areas (T3, T4) has completely melted, and Simultaneous changing of the positions (P1, P2; P1 to P5) of the at least two processing beams (4a,b) or of at least two further processing beams (25a-e) in at least two different further partial areas (T5, T6) of the connected surface area (2) until the powder layer (3) in the at least two further partial areas (T5, T6) has completely melted. procedure according to claim 1 , in which the continuous surface area (2) is surrounded by an edge contour (11) of the three-dimensional component (20), wherein the edge contour (11) and/or an edge region (12) formed between the edge contour (11) and the continuous surface area (2) is irradiated with the primary processing beam (4), in particular with the primary laser beam, or with a further processing beam (26), in particular with a further laser beam. procedure according to claim 1 or 2 , in which the different positions (P1, P2; P1 to P5) of the processing beams (4a,b; 4a-e) in the at least two partial areas (T3, T4) are offset from one another in a first direction (X) in the processing plane (E), and the simultaneous changing of the positions (P1, P2; P1 to P5) of the at least two processing beams (4a,b; 4a-e) in the at least two partial areas (T3, T4) comprises a simultaneous movement of the processing beams (4a,b; 4a-e) in a second direction (Y) in the processing plane (E), preferably perpendicular to the first direction. procedure according to claim 3 , in which a gas stream (13) is guided over the powder layer (3), the flow direction (+Y) of which is at least partially opposite to the direction of movement (-Y) of the processing beams (4a,b; 4a-e) and/or in which the order of irradiation of the partial regions (T1, T2, ...) preferably takes place as a function of the distance of the respective partial regions (T1, T2, ...) in the flow direction (+Y) from a provision device (21) for providing the gas stream (13). Method according to one of the Claims 3 or 4 , in which the positions (P1, P2) of the at least two processing beams (4a, 4b) in the first direction (X) have a distance (2 L) from one another which essentially corresponds to an integer multiple of the extension (L) of a respective partial region (T3, T4) in the first direction (X). Method according to one of the Claims 3 until 5 , in which a difference angle (δ ₁ , δ ₂ ) between the at least two processing beams (4a, 4b) in the first direction (X) when aligning the at least two processing beams (4a, 4b) to different positions (P1, P2) in the processing plane (E), the distance (A) of which in the processing plane (E) varies depending on the location depending on a deflection angle (α) of the scanner device (5), is selected such that either adjacent partial areas (T1, T2) in the middle of the processing area (B) adjoin one another in the first direction (X) or adjacent partial areas (T1, T2) at the edge of the processing area (B) adjoin one another in the first direction (X). Method according to one of the Claims 1 until 4 , in which the positions (P1 to P5) of the processing beams or of the further processing beams (25a-e) in the at least two further sub-areas are offset from one another in a second direction (Y) and the simultaneous change of the positions (P1 to P5) of the at least two processing beams or of the at least two further processing beams (25a-e) in the at least two further sub-areas results in a simultaneous movement directions of the processing beams or the further processing beams (25a-e) in a first direction (X), preferably perpendicular to the second direction. procedure according to claim 7 , further comprising: dividing a further primary processing beam (25) between the at least two further processing beams (25a-e), and guiding the at least two further processing beams (25a-e) to a further common scanner device (5a) for aligning the at least two further processing beams (25a-e) to different positions (P1 to P5) in the processing plane (E). Method according to one of the preceding claims, in which a focus position correction is carried out to correct the focus positions (F1, F2) of the processing beams (4a, 4b) in the beam path of the primary processing beam (4). Irradiation device (1) for a processing machine (15) for producing three-dimensional components (20) by irradiating powder layers (3), comprising: a beam splitter device (7, 24) for splitting a primary processing beam (4, 25), in particular a laser beam, into at least two processing beams (4a, b; 4a-e), in particular into at least two laser beams, and a scanner device (5) for aligning the at least two processing beams (4a, b; 4a-e) via the same scanner mirror(s) (6a, 6b) of the scanner device (5) to different positions (P1, P2; P1 to P5) in a processing plane (E), characterized by a control device (14) which is designed to control the positions (P1, P2; P1 to P5) of the at least two processing beams (4a, b; 4a-e) in at least two partial areas (T3, T4) of a contiguous surface area (2), which is divided into a plurality of preferably rhomboid, in particular diamond-shaped, rectangular or square partial regions (T1 to T6; T1, T2) for the irradiation, until the powder layer (3) in the at least two partial regions (T3, T4) has completely melted, and which is designed to simultaneously change the positions (P1, P2; P1 to P5) of the at least two processing beams (4a, 4b) or of at least two further processing beams (25a-e) in at least two different further partial regions (T5, T6) of the connected surface region (2) until the powder layer (3) in the at least two further partial regions (T5, T6) has completely melted. Irradiation facility according to claim 10 , further comprising: a further beam splitter device (24a) for splitting a further primary processing beam (25), in particular a further laser beam, into the at least two further processing beams (25a-e), in particular into the at least two further laser beams, and a further scanner device (5a) for aligning the at least two further processing beams (25a-e) to different positions (P1 to P5) in the processing plane (E). Irradiation facility according to claim 10 or 11 , in which the beam splitter device (7, 24) is designed to divide the primary processing beam (4, 25) into the at least two processing beams (4a, 4b; 4a-e) by dividing a beam cross-section (A) of the primary processing beam (4, 25). Irradiation facility according to claim 12 , in which the beam splitter device (7) is designed to split the primary processing beam (4) by deflecting at least a partial region (A /2) of the beam cross-section (A) of the primary processing beam (4). Irradiation facility according to claim 13 , in which the beam splitter device is designed as a wedge plate (7) that is transparent to the primary processing beam (4). Irradiation device according to one of the Claims 10 until 12 , in which the beam splitter device is designed as a diffractive optical element (24). Irradiation device according to one of the Claims 10 until 15 , further comprising: a movement device (8) for at least partially moving the beam splitter device (7, 24) into the beam cross-section (A) of the primary processing beam (4) and out of the beam cross-section (A) of the primary processing beam (4). Irradiation device according to one of the Claims 10 until 16 , further comprising: a focus position correction device (10) for correcting the focus positions (F1, F2) of the processing beams (4a, 4b), which is arranged in the beam path of the primary processing beam (4). Irradiation device according to one of the Claims 10 until 17 , further comprising: a preferably telecentric F-Theta lens (27) for focusing the processing beams (4a, 4b) in the processing plane (E). Processing machine (15) for producing three-dimensional components (20) by Irradiation of powder layers (3), comprising: an irradiation device (1) according to one of the preceding claims, and a processing chamber (16) with a processing plane (E) in which the powder layer (3) to be irradiated can be arranged. processing machine after claim 19 , further comprising: a provision device (21) for providing a gas stream (13) which flows over the processing plane (E) in a construction platform area (17) provided for the provision of a powder bed (19), and whose flow direction (+Y) is preferably at least partially directed against the direction of movement (-Y) of the processing beams (4a,b; 4a-e) and/or in which the control device (14) is designed to determine the order of irradiation of the partial areas (T1, T2, ...) depending on the distance of the respective partial areas (T1, T2, ...) in the flow direction (+Y) from a provision device (21) for providing the gas stream (13).

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