DE102019208119A1 - Process for joining two components to one another by laser welding and component arrangement - Google Patents

Abstract

The invention relates to a method for joining two components (1, 3) to one another by laser welding, a first component (1) and a second component (3) being arranged adjacent to one another to form a component arrangement (5) such that the Component arrangement (5) has an irradiation surface (7) which has a first partial irradiation surface (7.1) on the first component (1) and a second partial irradiation surface (7.2) on the second component (3), the The irradiation surface (7) is irradiated with a laser beam (11) along an irradiation direction in a joining area (9). The method is characterized in that - the irradiation area (7) has a gap (15) in the joining area (9) which starting from the irradiation surface (7) tapers in the irradiation direction, the first component (1) and the second component (3) being joined to one another by thermal conduction welding.

Description

The invention relates to a method for joining two components to one another by laser welding, and to a component arrangement of two components joined to one another by means of laser thermal conduction welding.

For joining components by laser welding, essentially two process regimes are known, which are differentiated from one another on a scale of the power density of the laser radiation used. There is a first regime of so-called heat conduction welding, which is also referred to as heat conduction seam welding. This regime is given at power densities up to an order of magnitude of 10 ⁵ W / cm ² . Here, a surface of the components to be joined is heated to such an extent that a locally limited melting process begins. The energy absorbed by the components gets inside the component through thermal conduction. A weld seam formed by thermal conduction welding typically has a lens-shaped seam geometry with a low aspect ratio, viewed in cross section or micrograph, with a seam depth typically being less than, but at most equal to, a seam width. If the power density on the surface of the components is increased to a magnitude of a few 10 ⁵ W / cm ² up to a few 10 ⁶ W / cm ² , a strong evaporation process begins. A vapor capillary is formed, which is essential for the reflection and absorption behavior of the laser radiation. It is precisely because of the vapor capillary that a substantial part of the radiated energy is coupled into the joint area. Furthermore, due to the vapor capillary, the laser radiation can penetrate much deeper into the components to be joined, from which the term “deep welding” for this welding regime is derived. Laser weld seams formed by deep welding have an aspect ratio of greater than 1, typically greater than 2, the seam depth being more than twice as large as the seam width.

The problem with the deep welding regime is that oxidation-sensitive materials cannot be welded reliably, since they form oxides precisely due to the formation of a vapor capillary, which contribute to embrittlement and thus to a low strength of the laser weld seam formed. Due to the high power coupled into the joint area, spatter occurs, which often prevents the formation of a smooth weld seam and contributes to the formation of pores. In addition, metal vapor is generated in the deep welding regime, which can be deposited in the vicinity of the laser weld seam. On the one hand, this is problematic for aesthetic reasons; on the other hand, it can lead to leakage currents or short circuits when welding electrical or electronic components. It also proves to be difficult to weld components made of different materials together. Gas-tight welds are hardly possible, especially when using materials that are sensitive to oxidation, due to the embrittlement of the seam. The application of this welding regime to sintered components that are manufactured additively or by means of a metal powder injection molding process (metal injection molding process - MIM process) is particularly problematic. When manufacturing such components, it cannot be completely ruled out that there are residual amounts of an organic binder material that is added to the metal powder and is important for forming the green part in metal powder injection molding, which then outgass, oxidize and form residues due to the high laser power during deep welding that greatly impair the aesthetic appearance of the welded components. Furthermore, the oxidation products of the residual binder also lead to embrittlement of the weld seam, so that a stable, gas-tight weld cannot be obtained. Sintered components also typically have pores in their interior that can be gas-filled. This gas can also be chemically changed in the laser welding regime, in particular react with the material of the sintered component and / or precipitate on the surface, which can result in an aesthetic and / or mechanical impairment of the weld. The creation of a weld seam with a well-defined seam depth is hardly possible in the deep welding regime, since the seam depth can hardly be controlled. Furthermore, thin-walled, in particular precision-engineered components can hardly be welded to one another in the deep-penetration welding regime, since there is a risk of welding through and thus destruction of the components or the resulting component assembly, in particular due to the hardly controllable seam depth.

The heat conduction welding regime, however, also has disadvantages: Because it can only produce comparatively flat weld seams, the depth of which can hardly be influenced, no stable connection between two components can be achieved in this regime that also holds under high pressure and in particular is gas-tight under such conditions.

It has been proposed to influence the seam depth in thermal conduction welding by adjusting the temperature at the weld pool surface and by adding process gases, in particular to increase it ( R. Daub, "Increasing the seam depth in laser beam heat conduction welding of steels", dissertation, Faculty of Mechanical Engineering, Technical University of Munich, 2012 ). Insofar as this is at all practicable, these measures cannot be used to increase the seam depth sufficiently and / or to precisely adjust the same geometry.

The invention is based on the object of creating a method for joining two components to one another by laser welding and a component arrangement with two components, the disadvantages mentioned not occurring.

The object is achieved by creating the subjects of the independent claims. Advantageous configurations result from the subclaims.

The object is achieved in particular by creating a method for joining two components to one another by laser welding, a first component and a second component being arranged adjacent to one another to form a component arrangement such that the component arrangement has an irradiation surface that has a first Having irradiation sub-area on the first component and a second irradiation sub-area on the second component. The irradiation area is irradiated with a laser beam along an irradiation direction in a joining area. The direction of irradiation corresponds in particular to the direction of propagation or propagation of the laser beam. It is provided here that the irradiation surface has a gap in the joining area which tapers in the irradiation direction starting from the irradiation surface. At the same time, the first component and the second component are joined to one another by thermal conduction welding. By providing the irradiation surface in the joint area with the gap, it is possible to influence the conditions for the formation of the laser weld seam in the heat conduction welding regime so that the seam geometry of the laser weld seam can be adjusted. In particular, the geometry of the laser weld seam in cross section or micrograph can be largely determined or specified by the geometry of the gap. It is thus possible, in particular, to use the gap that tapers in the direction of irradiation from the irradiation surface to form very stable weld seams in the heat conduction welding regime, which in particular can also have a depth that is greater than their width. Because of the laser radiation - in particular with the formation of multiple reflections of the laser radiation in the gap - material is melted from the walls of the gap, which then flows into the tapering gap and the gap quasi from below, i.e. from the side of the gap facing away from the irradiation surface, filled. In particular, the depth of the weld seam that is produced is thus determined / set essentially geometrically by the configuration of the gap which tapers in the direction of irradiation. The welding depth can be specified by the geometry of the gap.

The method is particularly suitable for welding thin-walled components together. This results in particular from the fact that in the method, on the one hand, the depth of the weld seam can be well defined so that there is no risk of welding through, while on the other hand, a stable, firm and, in particular, pressure-tight connection of the components to one another can be created.

The direction of irradiation is preferably selected to be parallel to a central plane or plane of symmetry of the gap. The direction of irradiation is preferably in the center plane or plane of symmetry. If the partial areas of irradiation are aligned with one another, the direction of irradiation is preferably perpendicular to the area of irradiation.

The walls of the gap are preferably partial areas of the irradiation area.

As a result of the multiple reflections occurring in the gap, significantly more energy can be introduced than would be possible if the irradiation surface were irradiated without the gap. This also contributes to the formation of more stable and / or deeper weld seams in the area of thermal conduction welding. Thus, the weld seams produced in this way have on the one hand all the properties and advantages of seams produced in the regime of thermal conduction welding, namely a smooth surface, high ductility, freedom from splashes, metal vapor and pores, avoidance of oxide formation during formation, and more, but at the same time very stable, gas- and pressure-tight seams can be formed, which in particular can also have a greater depth than corresponds to their width. Ductile, tough welded joints are created that are free from embrittlement, in particular due to oxides.

It is also possible to weld different joining partners to one another in the thermal conduction welding regime. It is also possible to weld thin-walled components, in particular with wall thicknesses from 0.1 mm to 4 mm, preferably from 0.2 mm to 3 mm, to one another or to thick-walled components without welding through and thus damaging the components is feared.

Sintered components, in particular additively manufactured components or those that are manufactured in a metal powder injection molding process, can easily be used with the one proposed here Processes are joined, as residual binder components do not oxidize and thus neither contribute to seam embrittlement, nor do unsightly deposits of oxidation products or residual gases form from pores.

It is important that the laser welding is carried out in the context of the method proposed here in the regime of thermal conduction welding. The power density is preferably less than 10 ⁶ W / cm ² , preferably less than 8 · 10 ⁵ W / cm ² , preferably less than 6 · 10 ⁵ W / cm ² , preferably less than 5 · 10 ⁵ W / cm ² , preferably less than 4 · 10 ⁵ W / cm ² , preferably less than 3 · 10 ⁵ W / cm ² , preferably less than 2 · 10 ⁵ W / cm ² , preferably less than 10 ⁵ W / cm ² , preferably less than 8 · 10 ⁴ W / cm ² , preferably less than 6 · 10 ⁴ W / cm ² , preferably less than 5 · 10 ⁴ W / cm ² . In particular, in thermal conduction welding, the power density is selected in such a way that heating of the component arrangement above the evaporation temperature of that component of the two components which has the lower evaporation temperature or above the evaporation temperature of the two components is avoided.

A cross section is understood to mean a view that lies in a plane in which the direction of irradiation is arranged as intended, a longitudinal direction of the gap and also of the laser weld seam formed extending perpendicular to this plane. The cross-sectional plane is thus in particular also a plane in which micrographs are usually made in order to be able to assess the quality of the weld and in particular the laser weld seam.

In the context of the method, at least one thin-walled component is preferably used as the first component and / or as the second component, the wall thickness of the at least one thin-walled component preferably from at least 0.1 mm to at most 4 mm, preferably from at least 0.2 mm to at most 3 mm. A thin-walled component, in particular with such a wall thickness, is particularly preferably used both as the first component and as the second component, so that at least two thin-walled components are particularly preferably welded to one another.

At least one component selected from the first component and the second component is preferably designed as a sheet metal. Alternatively or additionally, at least one component selected from the first component and the second component is preferably designed as a wire. Alternatively or in addition, at least one component selected from the first component and the second component is preferably designed as a rotationally symmetrical component, in particular as a shaft, axle, tube, or the like. With the method proposed here it is possible to join components formed as sheet metal with one another, but components formed as wires can also be joined to one another. A component designed as sheet metal can also be joined to a component designed as a wire. Wires with one another - or a wire in contact with a sheet metal - form, due to their round geometry, a line contact with the neighboring component, which quasi forms the gap base of the gap, which then has the irradiation surface. In particular, because of their round geometry, two wires arranged next to one another along their longitudinal extension, which lie against one another and which are irradiated with laser radiation perpendicular to their longitudinal extension, have a gap that tapers in the irradiation direction starting from the irradiation surface. During the welding of such wires - or an arrangement of a wire and a sheet metal - by means of the method proposed here, it has been found that the material melted from the walls of the gap fills the gap very efficiently, but not on the side facing away from the irradiation surface of the gap emerges from this. Thus, even such a fragile arrangement is not welded through, but rather a clean, stable weld seam is produced, the interconnected components also having an aesthetically favorable appearance from a side facing away from the weld seam, since no welding material escapes here and in particular no spatter reach. In particular, an optical quality like that of a soldered seam can be achieved. Components designed to be rotationally symmetrical can be welded with the method proposed here, in particular along a circumferential line - in particular all around along the entire circumference. It is preferably possible for both components to be designed as rotationally symmetrical components.

The irradiation surface can be flat. However, it is also possible that the irradiation surface is not planar or is only planar in certain areas. The irradiation surface is therefore by no means necessarily a plane. In particular, it is possible for the first partial irradiation surface to form an angle with the second partial irradiation surface, in particular if the first component and the second component are arranged almost at a corner butt against one another.

The first partial area of irradiation and the second partial area of irradiation are preferably separated from one another by the gap in the joining area.

In the joining area, the components to be joined preferably adjoin one another, or are at least arranged next to one another or adjacent to one another.

It is possible for the first component and the second component to be arranged directly adjacent to one another, in particular to be placed against one another, so that they touch one another. However, it is also possible that a distance remains between the first component and the second component, in particular small distances of at most 0.3 mm can be bridged with the method proposed here during laser welding. In particular, distances between the first component and the second component of the order of magnitude mentioned can be bridged by the method proposed here, since the material melted from the walls of the gap forms droplets which flow into the tapering gap and close it from below. The melted material solidifies before it can exit the gap again on the opposite side. The distance discussed here is in particular a smallest distance between the first component and the second component, which can be given in particular in the bottom of the gap.

In the context of the method proposed here, welding through the gap or through the gap is accordingly specifically avoided.

According to a further development of the invention, it is provided that the component arrangement is provided by the first component and the second component being arranged at a distance from one another which is at least 0 mm to at most 0.3 mm, preferably to at most 0.25 mm, preferably up to at most 0.2 mm, preferably at least 0.01 mm, preferably at least 0.02 mm, preferably at least 0.05 mm, preferably up to at most 0.1 mm. This distance is measured in particular in the joining area. If the distance is 0 mm, the components are in direct contact with one another. However, it is also possible that the components cannot be arranged at the same distance from one another along an entire extension of the joining area, be it due to surfaces that are not completely parallel or due to a component curvature in at least one direction. In this case, along the joining area - in particular along the extension of the weld seam to be formed - different distances can result, which in particular can lie in the areas mentioned here, wherein the distance can vary in particular in the areas mentioned. As already pointed out, such distances can easily be bridged during laser welding with the method proposed here.

In particular, the first component and the second component are arranged adjacent to one another at a distance in the areas mentioned, the component arrangement being obtained in this way.

According to a further development of the invention it is provided that a minimum distance between the first component and the second component is at least 0 mm to at most 0.3 mm, preferably up to at most 0.25 mm, preferably up to at most 0.2 mm, preferably at least 0 .01 mm, preferably at least 0.02 mm, preferably at least 0.05 mm, preferably at most 0.1 mm. The minimum distance is preferably measured in the joining area. The minimum distance represents, in particular, a shortest or smallest distance between the first component and the second component - in particular in the joining area. The minimum distance is accordingly preferably set in a targeted manner. As already stated, distances in the orders of magnitude or ranges mentioned here can easily be bridged within the scope of the method proposed here by laser welding.

The terms “gap” and “distance” are used here in particular as follows: The gap is formed in the joining area and tapers starting from the irradiation surface, so that a distance measured in the area of the gap between the first component and the second component is based on the Irradiation area reduced as seen in the direction of irradiation. The distance is now that distance between the components that is minimal in the irradiation direction in the region of the gap, in particular the distance at the end or foot of the gap, or a distance that is measured in the irradiation direction below the gap, i.e. facing away from the irradiation surface. The term “gap” thus denotes a certain geometric structure of the component arrangement, while the term “distance” denotes a certain distance between the first component and the second component, which in particular - viewed in the irradiation direction - is measured at a certain height, preferably at the foot of the gap or facing away from the irradiation area below the gap.

It is preferably provided that the first component and the second component are joined to one another without protective gas. With the method disclosed here, it is advantageously possible to produce oxide-free, ductile, tough, stable and, in particular, pressure-tight weld seams without using a protective gas.

According to a further development of the invention it is provided that an additional material is introduced into the gap. This way you can be beneficial In particular, larger distances between the components to be joined are bridged, in particular closed, and / or it is possible to weld the first component and the second component to one another even if not enough material can be melted from the walls of the gap in order to to close and / or fill the gap from below. In particular, the distance between the components to be joined can be bridged without the additional material penetrating through during the heat conduction welding.

The method can also be used in particular for larger components if an additional material is introduced into the gap. In particular, the method can be used for joining metal sheets to one another, in particular high-strength metal sheets, in particular body panels for a body, in particular an automobile body. In particular, the method can be used for joining metal sheets that are coated, in particular with an anti-corrosion coating, in particular with zinc. Such a coating, in particular zinc, is advantageously removed during the heat conduction welding so that the sheets can be joined together safely and stably. In particular, the method can be used for joining metal sheets in lightweight construction, in particular in lightweight body construction.

The additional material is preferably introduced into the gap during the irradiation with the laser beam, in particular in an area irradiated with the laser beam; or before irradiating with the laser beam; or the additional material is introduced into this region of the gap with a time delay from the start of the irradiation of an area irradiated with the laser beam. In particular, a device for introducing the additional material can lead the laser beam in the irradiation direction, be locally displaced together with the laser beam, or lag behind the laser beam. If the device for introducing the additional material is ahead of the laser beam, the additional material can first be introduced into the gap and then melted by the laser beam. With a simultaneous introduction of the additional material and irradiation of the same by the laser beam, the additional material is melted by the laser beam immediately when it is introduced into the gap. If the device for introducing the additional material follows the laser beam, the delay between the irradiation of a certain area and the introduction of the additional material is preferably set so that the additional material is introduced into the area that is still melted or so that the area in which the Additional material is introduced, has already melted at the time the additional material is introduced, but is still irradiated by the laser beam. In particular, in this way, any distance between the components can already be closed by melted material of the walls and then filled with the additional material, which is then melted by the laser beam without the additional material emerging from the gap on the opposite side in the irradiation direction can.

The additional material is preferably a metal or a metal alloy.

The additional material is preferably introduced into the gap as powder material. Alternatively or in addition, it is possible that the additional material is introduced into the gap as a wire.

According to a preferred embodiment it is provided that the additional material is blown into the gap as powder material. In particular, the powder material is preferably introduced into the gap before the irradiation, during the irradiation or with a delay to the irradiation. In particular, the powder material is preferably introduced into a welding area of the gap that is irradiated by the laser beam.

It is particularly preferably provided that the powder material is introduced into the gap, in particular blown into it, by a processing head, in particular a laser head, the processing head, in particular a laser head, also being set up to irradiate the irradiation surfaces with the laser beam. In particular, the machining head is designed as a laser beam source and preferably has a last part of a beam guiding optics or an exit window for the laser beam. In particular, a device for blowing the powder into the processing head is preferably integrated. The device can precede the laser beam and act simultaneously on the same point as the laser beam, for example by having a powder outlet of the device encompass the laser beam in a ring, or the device can lag behind the laser beam.

The additional material is preferably introduced into the gap in several steps or iterations. The gap is therefore in particular covered several times with the additional material and preferably with the laser beam.

It is particularly preferably provided that the gap is completely filled with the additional material. In this way, even larger gaps can be completely bridged and larger components can be securely joined together.

According to a preferred embodiment, it is provided that a weld seam formed in the course of the method is smoothed with the laser beam. The smoothing is preferably carried out by sweeping over the weld seam with the laser beam, in particular without using additional material. In this way, very smooth and aesthetic weld seams can be formed. The laser beam preferably sweeps over the weld seam for smoothing with reduced power or reduced power density compared to thermal conduction welding.

According to a further development of the invention it is provided that a quotient of a beam width dimension of the laser beam to a width of the gap measured in the irradiation area is at least 0.2 to at most 2.0. It has been found that in this area of the quotient particularly favorable results are obtained with a view to a stable weld seam. If the laser beam has a Gaussian beam profile, the beam width is preferably measured in a plane perpendicular to the direction of irradiation where the intensity of the laser beam is a factor of 1 / e ^{2 of} the intensity of the laser beam on the beam center axis, i.e. at the maximum intensity of the Gaussian profile . If the laser beam has a rectangular profile, the beam width dimension is easily defined by the rectangular profile. It is also possible for the laser beam to be shaped or masked out by suitable beam diaphragms or beam shaping. In this case too, the laser beam has a beam width dimension which is then determined in particular by the diaphragm diameter.

A beam width dimension here denotes, in particular, a beam width in the cross section of the laser beam, measured perpendicular to a feed direction along a longitudinal extension of the weld seam being created. In the case of a circular beam cross-section, the beam width dimension is in particular a beam diameter. For the sake of simplicity, the terms “beam width dimension” and “beam diameter” are used synonymously in the following, regardless of the specific shape or the specific profile of the laser beam in cross section.

According to a development of the invention it is provided that the quotient of the beam width dimension to the width of the gap is from at least 0.3 to at most 2.0; preferably from at least 0.4 to at most 2.0; preferably from at least 0.5 to at most 2.0; preferably from at least 0.6 to at most 1.9; preferably from at least 0.7 to at most 1.8; preferably to at most 1.7; preferably up to at most 1.6; preferably from at least 0.8 to at most 1.5; preferably from at least 0.9 to at most 1.4; preferably from at least 1.0 to at most 1.3; is preferably 1.2. It has been found that in the areas I have defined here, there are particularly favorable conditions for the formation of a stable laser weld seam within the scope of the method proposed here.

According to a development of the invention it is provided that the gap is provided symmetrically on the first component and on the second component. In this case, the component arrangement from the first component and the second component preferably has a plane of symmetry extending between the components, the entire gap geometry being mirrored on the plane of symmetry by mirroring the geometry of the first component in the area of the gap - or vice versa by mirroring the Geometry of the second component at the plane of symmetry - is obtained.

Alternatively, it is possible for the gap to be provided asymmetrically on the first component and on the second component, the walls of the gap on the components being able to differ in particular with regard to their curvature and / or their angle to the irradiation surface.

Alternatively, it is possible that the gap is formed on one side on a component selected from the first component and the second component. It is therefore possible that one of the components does not have any gap geometry, for example no bevel or rounding or the like, but rather, for example - as seen in cross section - is rectangular or rectangular. The other component can then, for example, have a chamfer or a rounding so that the gap is formed in the joining area.

Through the specific choice of a geometry for the gap, the geometry of the laser weld seam that is produced can be determined, whereby its properties are preferably also determined.

According to a development of the invention it is provided that the gap has at least one rounded wall. An example of such a rounded wall results from a wire that inherently has a round geometry - viewed in cross section. Two wires placed next to one another or one wire placed on a metal sheet thus have a gap with a rounded wall due to their own geometry. The gap particularly preferably has two rounded walls. This is the case, for example, with two wires arranged next to one another along their longitudinal direction, with two metal sheets arranged next to one another with rounded edges, or also with a sheet metal with rounded edge, next to which a wire is arranged.

Alternatively or additionally, it is possible for the gap to have at least one flat inclined wall. This is possible, for example, if at least one of the components has a bevel or some other bevel in the joining area. The gap preferably has two sloping walls. This is possible in particular in that both components arranged next to one another have a bevel or bevel in the joining area.

In this respect, too, the specific selection of a geometry for the gap makes a significant contribution to the properties of the laser weld seam that is formed, in particular to its geometric configuration.

At least one sheet metal with a rounded edge is preferably used as the at least one first and / or second component.

A gap, which has two flat sloping walls, is preferably triangular in cross section.

According to a development of the invention it is provided that the at least one rounded wall has a radius of at least 0.1 mm to at most 5 mm; preferably from at least 0.3 mm to at most 5 mm; preferably up to a maximum of 4.5 mm, preferably up to a maximum of 4 mm; preferably up to at most 3.5 mm; preferably up to a maximum of 3 mm; preferably up to a maximum of 2.7 mm; preferably from at least 0.4 mm to at most 2.6 mm; preferably from at least 0.5 mm to at most 2.5 mm; preferably from at least 0.6 mm to at most 2.4 mm; preferably from at least 0.7 mm to at most 2.3 mm; preferably from at least 0.8 mm to at most 2.2 mm; preferably from at least 0.9 mm to at most 2.1 mm; preferably from at least 1.0 mm to at most 2.0 mm; preferably from at least 1.1 mm to at most 1.9 mm; preferably from at least 1.2 mm to at most 1.8 mm; preferably from at least 1.3 mm to at most 1.7 mm; preferably from at least 1.4 mm to at most 1.6 mm; preferably 1.5 mm, preferably 0.65 mm. It has been found that with the radii defined here for the at least one rounded wall, preferably for the two rounded walls of the gap, particularly favorable conditions exist for the formation of a stable laser weld seam in the regime of heat conduction seam welding, with weld seams being able to be formed at the same time preferably have a depth which is greater than their width measured in the irradiation area.

Alternatively or additionally, it is preferably provided that a full opening angle of the gap, which has at least one inclined wall, of at least 15 ° to at most 60 °; preferably from at least 20 ° to at most 55 °; preferably from at least 30 ° to at most 45 °; preferably from at least 35 ° to at most 40 °; is preferably 37 °. A full opening angle is understood to mean an angle which overlaps the entire gap in the cross-sectional plane, that is to say extends from one wall of the gap to the opposite wall of the gap. It has been found that the angle ranges proposed here are particularly suitable for obtaining a stable laser weld seam in the heat conduction welding regime, the depth of which can in particular also be greater than its width measured in the irradiation area.

Alternatively or additionally, it is preferably provided that a quotient of a depth of the gap measured in the direction of irradiation starting from the irradiation area divided by the width of the gap measured in the irradiation area of at least 0.2, preferably of at least 0.3, preferably of at least 0, 5, preferably from at least 0.6 to at most 3.2; preferably from at least 0.7 to at most 3.1; preferably from at least 0.8 to at most 3.0; preferably from at least 0.9 to at most 2.9; preferably from at least 1.0 to at most 2.8; preferably from at least 1.2 to at most 2.6; preferably from at least 1.4 to at most 2.4; preferably from at least 1.6 to at most 2.2; preferably from at least 1.8 to at most 2.0; is preferably 1.9. It has been found that, in particular, the ranges specified here for the quotient of the depth of the gap to its width measured in the irradiation area enable the formation of a stable laser weld seam in the heat conduction welding regime.

According to a further development of the invention it is provided that the laser beam is generated in a CW mode or continuous wave mode (CW - Continuous Wave). The laser beam is thus generated as a continuous laser radiation. With a continuous laser beam, particularly smooth and homogeneous laser welds can be produced.

Alternatively it is possible that the laser beam is operated in a pulsed mode, i. is generated as pulsed laser radiation. In this way, higher power densities can be generated particularly well.

It is preferably provided that the irradiation surface is irradiated by the laser beam in a clocked operation. In this case, clocked operation can be achieved either by chopping a continuous laser beam generated in CW operation by a clocking device, for example a shutter, and thus clocking it, or that a pulsed laser beam is used. Of course, it is also possible to additionally clock a pulsed laser beam generated in pulsed operation by a clocking device, for example a shutter, for example in order to influence a clock frequency of the clocked operation. Particularly aesthetic weld seams can be produced in clocked operation.

In the clocked operation, a pulse length of at least 1 ms to at most 5 ms, preferably up to at most 3 ms, is preferably generated for a clock or a single irradiation event of the irradiation surface.

Alternatively, it is preferably provided that the irradiation surface is irradiated with the laser beam in continuous operation. For this purpose, a continuous laser beam generated in CW operation is preferably used, which is not timed by means of a clocking device.

Alternatively or additionally, it is preferably provided that the laser beam has a beam diameter of at least 0.1 mm to at most 2.5 mm; preferably up to a maximum of 2 mm; preferably up to at most 1.5 mm; preferably up to a maximum of 1 mm; preferably up to a maximum of 0.9 mm; preferably from at least 0.2 mm to at most 0.8 mm; preferably from at least 0.3 mm to at most 0.7 mm; preferably from at least 0.4 mm to at most 0.6 mm; preferably 0.5 mm or 0.4 mm is produced. It has been found that, in the ranges specified here for the beam diameter, particularly stable laser weld seams can be produced within the scope of the method proposed here.

As an alternative or in addition, it is preferably provided that the laser beam has a power of at least 50 W to at most 5 kW; preferably from at least 100 W to at most 5 kW; preferably up to a maximum of 4.5 kW; preferably up to a maximum of 4 kW; preferably up to a maximum of 3.5 kW; preferably up to a maximum of 3 kW; preferably up to a maximum of 2.5 kW; preferably from at least 250 W to at most 2 kW, preferably from 750 W is generated. In particular, the power is matched to the beam diameter in such a way that the power density is in the regime of thermal conduction welding.

Alternatively or additionally, it is preferably provided that the laser beam is generated with a wavelength of at least 400 nm to at most 1200 nm, preferably from at least 920 nm to at most 1064 nm, in particular 532 nm or 515 nm or 450 nm. This wavelength range is particularly suitable for heat conduction welding, in particular of MIM components. The wavelength of the laser beam is preferably matched to the absorption of the material used for the components or the absorption of the materials of the components.

Alternatively or additionally, it is preferably provided that the laser beam is fed at a feed rate of at least 0.25 m / min, preferably from at least 0.5 m / min to at most 30 m / min, preferably from at least 1 m / min to at most 25 m / min. min, preferably from at least 2 m / min to at most 20 m / min, preferably from at least 3 m / min to at most 17 m / min; preferably from at least 4 m / min to at most 16 m / min; preferably from at least 5 m / min to at most 15 m / min; preferably from at least 6 m / min to at most 14 m / min; preferably from at least 7 m / min to at most 13 m / min; preferably from at least 8 m / min to at most 12 m / min; preferably from at least 9 m / min to at most 11 m / min; is preferably displaced by 10 m / min or 12 m / min along the gap relative to the component arrangement. The feed rates mentioned here ensure the stable formation of a laser weld seam within the scope of the method proposed here. The laser beam is particularly preferred in the clocked operation with a feed rate of at least 0.25 m / min, preferably from at least 0.5 m / min to at most 3 m / min, preferably to at most 1 m / min, along the gap relative to the component arrangement relocated. Alternatively or additionally, the laser beam is preferably displaced in continuous operation at a feed rate of at least 3 m / min to at most 30 m / min along the gap relative to the component arrangement. In this way, the feed rate can advantageously be matched to the operating mode of the irradiation of the irradiation surface.

According to a development of the invention, it is provided that the laser beam is generated by means of a laser selected from a group consisting of a diode laser, a fiber laser, an Nd: YAG laser, in particular a flash lamp-pumped Nd: YAG laser, and a disk laser , particularly a diode-pumped disk laser. The laser types proposed here have proven to be particularly suitable for producing stable laser welds within the scope of the method proposed here.

According to a development of the invention, it is provided that at least one component selected from the first component and the second component has at least one material or consists of a material selected from a group consisting of nickel silver, INOX, in particular INOX 316L, copper or a copper alloy, and titanium. In particular, such components can be welded within the scope of the method proposed here without the occurrence of oxidation products which embrittle the weld seam. The method proposed here is particularly suitable for these materials. According to a preferred embodiment, it is provided that the first component and the second component each have a material or consist of a material that is selected from the aforementioned group.

Particular advantages arise when the method disclosed here is applied to a material which comprises copper or a copper alloy or is copper or a copper alloy. In particular, particular advantages result if a wavelength of 532 nm, 515 nm or 450 nm, generally a green or blue wavelength, is selected for the laser beam. The multiple reflections in the gap resulting from the process are particularly advantageous when welding copper and copper alloys. The possibility of thermal conduction welding is expanded, in particular to greater seam depths. Furthermore, the method disclosed here is particularly suitable for thin wall thicknesses.

Alternatively or additionally, it is preferably provided that at least one component, selected from the first component and the second component, is produced as a sintered component. In the case of the method disclosed here, in particular residual gas quantities arranged in pores of the sintered component do not have a disadvantageous effect on the quality of the weld seam produced or the weld in general.

A sintered component is understood here to mean, in particular, a component which is produced by sintering, in particular at least one method step in the production of the component being sintering or a sintering step.

In particular, it is preferably provided that at least one component, selected from the first component and the second component, is manufactured as an additively manufactured sintered component, for example by laser sintering.

Alternatively or in addition, it is preferably provided that at least one component selected from the first component and the second component is manufactured as an MIM component, that is to say by a metal injection molding process (Metal Injection Molding - MIM). The advantages of the method are realized in a special way, since such components can be welded with the method proposed here without the risk of oxidation of residual binder components and the negative consequences resulting therefrom.

According to a preferred embodiment, it is provided that both components, that is to say the first component and the second component, are manufactured as sintered components, in particular as additively manufactured sintered components or as MIM components. It is of course also preferably possible for one of the components to be manufactured as an additively manufactured sintered component and the other component of the components to be manufactured as an MIM component.

According to a further development of the invention it is provided that a laser weld seam is produced, a width of the laser weld seam measured in the irradiation surface perpendicular to the longitudinal extension of the laser weld seam of at least 0.1 mm to at most 3 mm; preferably up to at most 2.5 mm; preferably up to a maximum of 2 mm; preferably up to at most 1.5 mm; preferably up to a maximum of 1 mm; preferably up to a maximum of 0.9 mm; preferably from at least 0.2 mm to at most 0.8 mm; preferably from at least 0.3 mm to at most 0.7 mm; preferably from at least 0.4 mm to at most 0.6 mm; is preferably 0.5 mm or 0.4 mm. The laser weld seam is preferably produced as an elongated, continuous weld seam or weld seam generated by overlapping, offset pulses along a curve, in particular a straight line, so that it has a longitudinal extension. The width of the laser weld seam is measured perpendicular to the longitudinal extension. With the widths measured here, stable weld seams that are gas-tight even under pressure can be formed.

Alternatively or additionally, it is preferably provided that a depth of the laser weld seam measured in the irradiation direction is greater than the width of the laser weld seam measured in the irradiation surface perpendicular to the longitudinal extension of the laser weld seam. In this way - as already explained - a particularly stable laser weld seam with the geometrical characteristic of a deep-welded weld seam, but in the regime of thermal conduction welding, is produced.

The laser weld seam is particularly preferably produced with a ratio of the depth measured in the irradiation direction to the width (aspect ratio) measured in the irradiation surface perpendicular to the longitudinal extension of the laser weld seam of at least 1 to at most 3.

However, it is also possible to specifically produce a laser weld seam in which the ratio of the depth measured in the direction of irradiation to the width measured in the irradiation surface perpendicular to the longitudinal extension of the laser weld seam, i.e. the aspect ratio, of at least 0.15 to at most 0.5, preferably from at least 0.2 to at most 0.3. With the method disclosed here, such laser welds can also be made very stable, especially ductile and tough, with high strength and gas-tight.

According to a further development of the invention it is provided that the laser beam is displaced several times - in particular one after the other - along the gap relative to the component arrangement. In this way it is possible to produce the laser weld seam in multiple layers. In particular, the laser weld seam is executed in several passes or, in the case of rotationally symmetrical parts, in particular axles, shafts or tubes, with several revolutions. In this way, in particular, laser welds can be produced whose depth measured in the direction of irradiation is significantly greater than the width measured in the irradiation surface perpendicular to the longitudinal extent of the laser weld, a ratio of this depth to the width, which is also referred to as the aspect ratio, is preferably greater than 2. Such a large aspect ratio can otherwise be represented in a known manner only by deep welding, whereby it can also be achieved in the regime of thermal conduction welding by means of the method proposed here.

Alternatively, it is also possible for the laser weld seam to be produced in one pass, with the laser beam being displaced once along the gap relative to the component arrangement.

According to a development of the invention it is provided that the laser beam is displaced several times in succession along the gap relative to the component arrangement, the laser beam from at least twice to at most five times, preferably from at least twice to at most four times, preferably from at least twice to at most is shifted three times, in particular along the same displacement path, along the gap relative to the component arrangement. The weld is thus divided into several partial welds, which enables a particularly good weld result and, in particular, a particularly large aspect ratio for the laser weld seam.

According to a further development of the invention, it is provided that an area of action of the laser beam in which the laser beam interacts with the components is different for at least two displacements of the laser beam along the gap — along the same displacement path. The laser beam is thus displaced several times along the gap relative to the component arrangement, the effective area at least for a first displacement along the gap being different from the effective area for at least a second displacement. In particular, it is possible that the effective surface is selected differently for all displacements of a plurality of such displacements of the laser beam along the gap. In particular, the size of the active area, preferably a width dimension, in particular a diameter of the active area, is varied.

Particularly preferably, the size of the effective area, in particular the width dimension or the diameter of the effective area, increases from a first displacement to a next displacement of the laser beam, in particular successively from each previous displacement to each subsequent displacement. The increase in the size of the effective area is particularly preferably linear.

Preferably, the width dimension, in particular the diameter, of the effective area during a first displacement of the laser beam of a plurality of displacements is smaller than the width of the gap, preferably a quotient of the width dimension, in particular the diameter, of the effective area to the gap width is at least 0.3 to at most 0.9. The width dimension, in particular the diameter, of the effective surface for at least two displacements of a plurality of displacements of the laser beam along the gap is preferably smaller than the gap width, the quotient of the width dimension to the width of the gap being at least 0.3 to at most 0.9 . The width dimension of the active surface, in particular its diameter, is preferably greater than or equal to the width of the gap during a last displacement of a plurality of displacements of the laser beam along the gap, in particular only during the last displacement, the quotient of the width dimension to the The width of the gap is preferably from at least 1.0 to at most 2.0.

A subdivision of the weld into several partial welds, and in particular starting with a partial weld with a comparatively small effective area with an increasingly larger effective area thereafter, advantageously enables the flow behavior of the material in the gap to be optimized. The gap is initially widened by the first partial weld - and possibly further, subsequent partial welds - so that later, especially in subsequent partial welds with a larger effective area, melted material can flow into the widened gap above the widening zone initially created. In this way, particularly large aspect ratios can be achieved for the laser weld seam. In particular, the gap with the first partial weld can be widened or deepened downwards, that is to say in the direction of irradiation.

According to a preferred embodiment, a varying effective area is generated by varying the beam diameter of the laser beam. In particular, the beam diameter can be the Correspond to the diameter of the effective area, and the jet area, which is determined by the jet diameter, is identical to the effective area. Alternatively, it is possible that the varying effective area is generated by a displacement movement of the laser beam superimposed on the displacement along the gap, in particular a so-called wobble movement, so that the effective area is larger than the beam diameter due to the displacement movement of the laser beam. In order to enlarge the effective area, in particular the amplitude of this displacement movement, in particular the wobbling movement, can be increased. The displacement movement for varying the effective area has a higher displacement speed than the displacement of the laser beam along the gap, so that a desired effective area is generated almost instantaneously at a location of the gap by the displacement movement superimposed on the displacement of the laser beam along the gap, in particular the wobbling movement becomes.

According to a further development of the invention it is provided that the power of the laser beam with a first shift of the laser beam along the gap is different from the power of the laser beam with a second shift of the laser beam along the gap, if the laser beam several times along the gap - in particular along the same Relocation route - is relocated. The performance is preferably varied from relocation to relocation. In particular, performance preferably increases from each preceding displacement of a plurality of displacements to a subsequent displacement of the plurality of displacements. The variation of the power is preferably selected in such a way that a constant power density results in the respective effective areas. Thus, the area performance or the power density can advantageously be kept constant over the successive displacements.

According to a further development of the invention it is provided that a thin-walled component with a wall thickness of at least 0.1 mm to at most 4 mm, preferably of at least 0.2 mm to at most 3 mm, is used as the first component and / or as the second component. The method proposed here is particularly suitable for welding thin-walled components. According to the invention, the thin-walled component can preferably be a sheet metal or tube.

A thin-walled component, in particular sheet metal, with a wall thickness of at least 0.1 mm to at most 4 mm, preferably from at least 0.2 mm to at most 3 mm, is particularly preferably used as the first component, with a component with a greater wall thickness as the second component than it has the first component, in particular with a wall thickness of more than 3 mm, in particular a sheet metal, is used. The method proposed here is particularly suitable for joining components of different thickness or strength.

According to a development of the invention it is provided that a thin-walled tube with a wall thickness of at least 0.1 mm to at most 4 mm, preferably of at least 0.2 mm to at most 3 mm, is used as the first component and / or as the second component. A thin-walled tube with a wall thickness of at least 0.1 mm to at most 4 mm, preferably of at least 0.2 mm to at most 3 mm, is particularly preferably used as the first component, a flange being used as the second component. The method proposed here is particularly suitable for connecting thin-walled pipes to - in particular comparatively thick-walled - flanges.

According to a particularly preferred embodiment of the method, at least one thin-walled component, in particular with a wall thickness of at least 0.1 mm to at most 4 mm, preferably from at least 0.2 mm to at most 3 mm, is welded to another component.

In general, the method is preferably applied to components that have an oxidation-sensitive material or consist of at least one oxidation-sensitive material.

With the help of the process, smooth, clean weld seams can be produced without spatter.

The method is particularly preferably used for producing gas-tight weld seams in the case of thin-walled pipes in the circumferential direction.

The object is finally also achieved in that a component arrangement is created which has a first component and a second component, the first component and the second component being joined to one another by means of laser heat conduction welding, a laser weld seam in a joint area of the component Arrangement preferably has a depth which is greater than its width, the corresponding aspect ratio being greater than 1, preferably at least 2, where it is preferably greater than 2, where it is preferably at most 3. Alternatively, however, a laser weld seam with an aspect ratio of at least 0.15 to at most 0.5, in particular of at least 0.2 to at most 0.3, can also be produced. In the manner described here, a very stable laser weld seam, especially gas-tight under pressure, is produced in the heat conduction welding regime without the risk of seam embrittlement due to oxidation products, spatter or weld pores, generated. In particular, the advantages that have already been explained in connection with the method result in connection with the component arrangement.

The fact that the laser weld seam has a certain aspect ratio in the joining area of the component arrangement can be determined in particular in cross-sectional micrographs of the component arrangement.

The component arrangement is particularly preferably obtained by means of a method according to the invention or a method according to one of the embodiments described above.

Alternatively or additionally, it is provided that at least one component, selected from the first component and the second component, is used as a sintered component, in particular as an additively manufactured sintered component or as a MIM component, i.e. is designed as a component produced in a metal powder injection molding process. As already explained, the advantages of the method result in a special way in this case. In the heat conduction welding regime, no residual binder constituents of such an MIM component are oxidized, although stable, in particular gas- and pressure-tight, laser weld seams can nonetheless be obtained with the method. In general, residual gas fractions in pores of sintered components do not have a negative effect on the weld if the welding process disclosed here is used.

Both components, namely the first component and the second component, are particularly preferably designed as sintered components.

According to a development of the invention it is provided that at least one component selected from the first component and the second component has copper or a copper alloy, or consists of copper or a copper alloy. These materials can be laser-welded particularly well at a wavelength of 532 nm, 515 nm or 450 nm. In connection with copper or a copper alloy, the advantages of the method disclosed here are realized in a special way, especially if a green or blue laser beam, preferably with a wavelength of 532 nm, 515 nm or 450 nm, is used. The multiple reflections in the gap have a particularly advantageous effect, as a result of which the heat conduction welding regime in particular can be expanded to greater seam depths and can also be used for thin wall thicknesses.

Overall, the method disclosed here can produce tough, high-quality weld seams that are oxide-free and, in particular, have no embrittlement. The welding can also take place without distortion, tarnishing and smoke-free. A strength of the connection between the two components in the area of the weld seam of more than 250 N can advantageously be achieved.

• 1 eine schematische Darstellung einer ersten Ausführungsform eines Verfahrens zum Fügen zweier Bauteile miteinander durch Laserschweißen;
• 2 eine schematische Darstellung eines Ausführungsbeispiels einer Bauteil-Anordnung zweier mittels Laser-Wärmeleitungsschweißen miteinander gefügter Bauteile;
• 3 eine schematische Darstellung einer zweiten Ausführungsform des Verfahrens;
• 4 eine schematische Darstellung einer dritten Ausführungsform des Verfahrens;
• 5 eine schematische Darstellung einer vierten Ausführungsform des Verfahrens;
• 6 eine schematische Darstellung einer fünften Ausführungsform des Verfahrens, und
• 7 eine schematische Darstellung einer sechsten Ausführungsform des Verfahrens.

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

• 1 a schematic representation of a first embodiment of a method for joining two components to one another by laser welding;
• 2 a schematic representation of an embodiment of a component arrangement of two components joined together by means of laser thermal conduction welding;
• 3 a schematic representation of a second embodiment of the method;
• 4th a schematic representation of a third embodiment of the method;
• 5 a schematic representation of a fourth embodiment of the method;
• 6th a schematic representation of a fifth embodiment of the method, and
• 7th a schematic representation of a sixth embodiment of the method.

1 shows a schematic representation of a method for joining two components to one another by laser welding, with a first component 1 and a second component 3 such a component arrangement 5 are arranged adjacent to one another that the component arrangement 5 an irradiation area 7th having a first partial irradiation area 7.1 on the first component 1 and a second partial irradiation area 7.2 on the second component 3 having. The irradiation area 7th is in this case along an irradiation direction represented here by a first arrow P1 in a joining area 9 with a laser beam 11 irradiated. It is used to generate the laser beam 11 here a laser beam source 13th , in particular a laser, is provided. The laser beam source 13th a last decoupling unit, for example a laser beam 11 leading glass fiber, a last mirror, or another beam-guiding or beam-deflecting optical element in front of the joining area 9 be starting from which the laser beam 11 free up to the joining area 9 propagated. The direction of irradiation extends from the laser beam source 13th in the direction of the joining area 9 .

The laser beam 11 is preferably relative to the component arrangement 5 moved along a longitudinal extension of the laser weld to be generated. Alternatively or additionally, the component arrangement 5 compared to the - possibly stationary - truck beam 11 be moved.

The irradiation area 7th points in the joint area 9 a crack 15th on, which is based on the irradiation surface 7th tapered in the direction of irradiation. The first component 1 and the second component 3 are joined together by thermal conduction welding.

In this way it is possible to produce a stable, non-brittle, in particular oxide-free, laser weld seam 17th form whose geometry is essentially determined by the geometry of the gap 15th is determined. The laser weld seam 17th in particular are produced with a depth which is greater than their in the irradiation surface 7th measured width, in particular with an aspect ratio greater than 2. The depth of the laser weld seam 17th extends starting from the irradiation surface 7th seen in the direction of irradiation into the gap 15th inside.

In the embodiment of the method presented here, the gap is 15th symmetrically on the first component 1 and on the second component 3 educated. The gap 15th at least one rounded wall 19th , 19 ' on. In particular, the gap 15th here two rounded walls 19th , 19 ' on.

In particular, the components 1 , 3 here as wires, in particular as circular cylindrical wires, which are arranged next to one another along their longitudinal extension, so that at best - when they are close to one another - have a line contact with one another. But they can also be arranged at a short distance from one another. The method described here is advantageous in that the gap 15th between the wires is filled by material melted from their surfaces, without the melted material on the side facing the laser beam source 13th is turned away, exits. In this way, a very clean, stable and at the same time aesthetically pleasing fastening of the two wires to one another can be achieved from both sides. In particular, an optical quality like that of a soldered seam can be achieved.

2 shows a schematic representation of an embodiment of a component arrangement 5 , in particular in the context of the procedure according to 1 manufactured component arrangement 5 . Identical and functionally identical elements are provided with the same reference symbols, so that in this respect reference is made to the preceding description. 2 shows in particular a cross-sectional representation of the component arrangement 5 as is typically used for a micrograph to assess the quality of the laser weld seam 17th is won. The first component 1 and the second component 3 are joined to one another by means of laser thermal conduction welding, the laser weld seam 17th in the joining area 9 the component arrangement 5 has a depth that is greater than its width.

Based on 2 It is also evident that this is due to the surfaces and especially the walls 19th , 19 ' of the gap 15th melted material the gap 15th refills without affecting the laser beam source 13th or here the laser weld 17th remote side of the component arrangement 5 to get.

At least one of the components is preferred 1 , 3 produced or designed as a sintered component, in particular as a MIM component. Both components are particularly preferred 1 , 3 manufactured or designed as a sintered component, in particular as MIM components. The advantages of the method are realized in a special way, since in the heat conduction welding regime there is no risk of interference from residual gas from pores and no oxidation of residual binder components. At the same time, a very stable laser weld seam can be achieved 17th be generated.

In the embodiment according to 1 of the method and the embodiment according to 2 the component arrangement 5 a wire diameter for the components is particularly preferred 1 , 3 of at least 1.0 mm to at most 5.0 mm, preferably of 1.3 mm is used. One in the exposure area 7th measured width of the laser weld seam 17th is preferably from at least 0.2 mm to at most 3 mm, preferably 0.4 mm.

It is possible that the laser beam 11 is generated in CW operation. In this case in particular, a feed rate along an in 1 longitudinal extension of the laser weld seam shown by a second arrow P2 17th preferably from at least 5 m / min to at most 15 m / min, particularly preferably 12 m / min. The laser power of the laser beam 11 is preferably from at least 250 W to at most 5 kW, preferably 750 W.

The laser beam 11 is preferably generated with a wavelength of at least 400 nm to at most 1200 nm, preferably from at least 920 nm to at most 1064 nm, in particular 532 nm, 515 nm or 450 nm.

It is also possible that the laser beam 11 is generated in a pulse mode.

In particular, the irradiation surface is irradiated 7th by the laser beam 11 possible in clocked operation or in continuous operation.

The laser beam 11 is preferably generated with a beam diameter of at least 0.2 mm to at most 2.5 mm, particularly preferably 0.4 mm.

The laser beam 11 is preferably generated by means of a laser which is selected from a group consisting of a diode laser, a fiber laser, an Nd: YAG laser, and a disk laser, in particular a diode-pumped disk laser.

At least one component selected from the first component 1 and the second component 3 , preferably has a material or consists of a material which is selected from a group consisting of German silver, INOX, in particular INOX 316L, copper or a copper alloy, and titanium. Both components particularly preferably have 1 , 3 such a material or consist of such a material.

3 shows a schematic representation of a second embodiment of the method. Identical and functionally identical elements are provided with the same reference symbols, so that in this respect reference is made to the preceding description. The components 1 , 3 are designed here as sheets, with the gap 15th two rounded walls 19th , 19 ' having. The rounded changes 19th , 19 ' can have different radii or the same radius.

Preferably at least one radius is from one of the rounded walls 19th , 19 ' from at least 0.1 mm to at most 5 mm; preferably from at least 0.3 mm to at most 5 mm; preferably up to a maximum of 4.5 mm, preferably up to a maximum of 4 mm; preferably up to at most 3.5 mm; preferably up to a maximum of 3 mm; preferably up to a maximum of 2.7 mm; preferably from at least 0.4 mm to at most 2.6 mm; preferably from at least 0.5 mm to at most 2.5 mm; preferably from at least 0.6 mm to at most 2.4 mm; preferably from at least 0.7 mm to at most 2.3 mm; preferably from at least 0.8 mm to at most 2.2 mm; preferably from at least 0.9 mm to at most 2.1 mm; preferably from at least 1.0 mm to at most 2.0 mm; preferably from at least 1.1 mm to at most 1.9 mm; preferably from at least 1.2 mm to at most 1.8 mm; preferably from at least 1.3 mm to at most 1.7 mm; preferably from at least 1.4 mm to at most 1.6 mm; preferably 1.5 mm, preferably 0.65 mm.

The components 1 , 3 are here in particular at a distance A, in particular a minimum distance A, from one another, which is from at least 0 mm to at most 0.3 mm, preferably to at most 0.25 mm, preferably to at most 0.2 mm, preferably to at most 0, 1 mm, preferably at least 0.01 mm, preferably at least 0.05 mm. In a preferred embodiment, the distance A is selected specifically in this area.

4th shows a schematic representation of a third embodiment of the method. Identical and functionally identical elements are provided with the same reference symbols, so that in this respect reference is made to the preceding description. The components 1 , 3 are arranged here at a corner and thus perpendicular to each other. The gap 15th has at least one flat sloping wall, here two sloping walls in the form of the sloping walls 19th , 19 ' on. These are preferably provided by the components 1 , 3 are chamfered accordingly. In the embodiment shown here, too, the gap is symmetrical on the first component 1 and on the second component 3 educated.

5 shows a schematic representation of a fourth embodiment of the method. Identical and functionally identical elements are provided with the same reference symbols, so that in this respect reference is made to the preceding description. While in the figures shown above in the embodiments and exemplary embodiments shown there, the partial areas of irradiation 7.1 , 7.2 were arranged parallel to one another and aligned with one another, these are now in the 5 illustrated embodiment at a corner, in particular arranged at an angle of 90 ° to each other, so that the irradiation surface 7th overall is not flat.

The gap 15th is here on one side of one of the components 1 , 3 - here on the first component 1 - Formed, with only one flat inclined wall, namely the first wall formed as a bevel 19th having. The second wall 19 ' of the gap 15th is here without any beveling or chamfering by the flat, second partial surface of irradiation 7.2 of the second component 3 educated.

The gap 15th is designed in particular as a fillet weld.

6th shows a schematic representation of a fifth embodiment of the method. Identical and functionally identical elements are provided with the same reference symbols, so that in this respect reference is made to the preceding description. The following parameters are shown here schematically: A beam width dimension or diameter D of the laser beam 11 , one in the exposure area 7th perpendicular to the longitudinal extension of the laser weld seam 17th measured width B of the gap 15th , one in the direction of irradiation starting from the Irradiation area 7th measured depth T of the gap 15th , and a full opening angle α of the gap 15th .

A quotient of the beam diameter is preferably D to the width B of the gap 15th from at least 0.2 to at most 2.0; preferably from at least 0.3 to at most 2.0; preferably from at least 0.4 to at most 2.0; preferably from at least 0.5 to at most 2.0; preferably from at least 0.6 to at most 1.9; preferably from at least 0.7 to at most 1.8; preferably to at most 1.7; preferably up to at most 1.6; preferably from at least 0.8 to at most 1.5; preferably from at least 0.9 to at most 1.4; preferably from at least 1.0 to at most 1.3; preferably 1.2.

The full opening angle α of the gap 15th is preferably from at least 15 ° to at most 60 °; preferably from at least 20 ° to at most 55 °; preferably from at least 30 ° to at most 45 °; preferably from at least 35 ° to at most 40 °; preferably 37 °.

A quotient of the depth T of the gap 15th its width B is preferably at least 0.2, preferably at least 0.3, preferably at least 0.5, preferably from at least 0.6 to at most 3.2; preferably from at least 0.7 to at most 3.1; preferably from at least 0.8 to at most 3.0; preferably from at least 0.9 to at most 2.9; preferably from at least 1.0 to at most 2.8; preferably from at least 1.2 to at most 2.6; preferably from at least 1.4 to at most 2.4; preferably from at least 1.6 to at most 2.2; preferably from at least 1.8 to at most 2.0; preferably 1.9.

One in the exposure area 7th perpendicular to the longitudinal extension of the laser weld seam 17th measured width of the laser weld seam 17th is preferably from at least 0.1 mm to at most 3 mm; preferably from at least 0.2 mm to at most 0.8 mm; preferably from at least 0.3 mm to at most 0.7 mm; preferably from at least 0.4 mm to at most 0.6 mm; preferably 0.5 mm or 0.4 mm.

It is possible that the laser beam 11 once or several times - in particular successively in time - along the gap 15th relative to the component arrangement 5 is relocated. In the case of a multiple displacement along the same displacement route along the gap 15th can be a variation of an effective area of the laser beam 11 on the components 1 , 3 - in particular by a variation of one of the displacement along the gap 15th superimposed wobble movement and / or by varying the beam diameter D - be provided. In particular, the area of action can increase from displacement to displacement. Alternatively or additionally, a variation in the power of the laser beam can be used 11 be provided in the event of multiple relocation, in particular from relocation to relocation. A surface power or power density of the laser beam in the - preferably varying - effective area is preferably kept constant.

In a specific exemplary embodiment, it is possible that the laser beam 11 at a first shift along the gap 15th has an effective area with a diameter of 0.15 mm, the effective area having a diameter of 0.3 mm for a second displacement along the same displacement path and a diameter of 0.5 mm for a third displacement. The area power or power density of the laser beam is preferably used here 11 kept constant.

In cyclic operation, the feed rate is preferably at least 0.25 m / min, preferably from at least 0.5 m / min to at most 3 m / min, preferably to at most 1 m / min; in continuous operation it is preferably from at least 3 m / min to at most 30 m / min.

7th shows a schematic representation of a sixth embodiment of the method. Identical and functionally identical elements are provided with the same reference symbols, so that in this respect reference is made to the preceding description. It is provided in the sixth embodiment of the method that in the gap 15th an additional material 21st is introduced. This enables larger components in particular 1 , 3 joined together and / or larger gaps 15th be bridged.

The additional material 21st is preferably a metal or a metal alloy. The additional material is particularly preferred 21st as wire 23 or as powder material in the gap 15th brought in.

Will the additional material 21st as powder material in the gap 15th introduced, it is preferably in the gap 15th blown in, it being particularly preferred in one with the laser beam 11 irradiated welding area is blown.

The additional material 21st is preferred during the irradiation with the laser beam 11 before the irradiation, or with a delay to the irradiation in the welding area.

It is possible that a device for introducing the additional material 21st integral with the laser beam source 13th is trained. The device can be arranged in such a way that it is exposed to the laser beam 11 runs forward, the gap 15th at the same time as the laser beam 11 or the laser beam 11 runs after.

It is possible that the gap 15th several times with the additional material 21st and the laser beam 11 is painted over. Preferably the gap 15th complete with the additional material 21st filled.

A heat conduction weld seam formed in this way is then preferably made by wiping over it with the laser beam 11 - particularly preferred with reduced power density - smoothed.

Overall, a stable, geometrically precisely defined laser weld seam can be achieved with the method proposed here 17th can be generated in the heat conduction welding regime, with the component arrangement proposed here 5 through a correspondingly stable and non-brittle laser weld seam 17th excels.

QUOTES INCLUDED IN THE DESCRIPTION

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

Non-patent literature cited

• R. Daub, "Increasing the seam depth in laser-beam thermal conduction welding of steels", dissertation, Faculty of Mechanical Engineering, Technical University of Munich, 2012 [0005]

Claims (15)

Method for joining two components (1,3) to one another by laser welding, wherein - a first component (1) and a second component (3) are arranged adjacent to one another to form a component arrangement (5) that - the component arrangement ( 5) has an irradiation surface (7) which has a first partial irradiation surface (7.1) on the first component (1) and a second partial irradiation surface (7.2) on the second component (3), wherein - the irradiation surface (7) is irradiated with a laser beam (11) along an irradiation direction in a joining area (9), characterized in that - the irradiation surface (7) in the joining area (9) has a gap (15) which extends from the irradiation surface (7) tapered in the direction of irradiation, with the first component (1) and the second component (3) being joined to one another by thermal conduction welding. Procedure according to Claim 1 , characterized in that the component arrangement (5) is provided in that the first component (1) and the second component (3) are arranged at a distance from one another of at least 0 mm to at most 0.3 mm, preferably up to is at most 0.25 mm, preferably up to at most 0.2 mm, preferably at least 0.01 mm, preferably at least 0.05 mm, preferably at most 0.1 mm. Method according to one of the preceding claims, characterized in that a minimum distance between the first component (1) and the second component (3) - in particular in the joining area (9) - is at least 0 mm to at most 0.3 mm, preferably up to is at most 0.25 mm, preferably up to at most 0.2 mm, preferably at least 0.01 mm, preferably at least 0.05 mm, preferably at most 0.1 mm. Method according to one of the preceding claims, characterized in that an additional material (21) is introduced into the gap (15). Method according to one of the preceding claims, characterized in that a quotient of a beam width dimension (D) of the laser beam (11) to a width (B) of the gap (15) measured in the irradiation surface (7) of at least 0.2 to at most 2.0, preferably from at least 0.3 to at most 2.0; preferably from at least 0.4 to at most 2.0; preferably from at least 0.5 to at most 2.0; preferably from at least 0.6 to at most 1.9; preferably from at least 0.7 to at most 1.8; preferably to at most 1.7; preferably up to at most 1.6; preferably from at least 0.8 to at most 1.5; preferably from at least 0.9 to at most 1.4; preferably from at least 1.0 to at most 1.3; is preferably 1.2. Method according to one of the preceding claims, characterized in that the gap (15) a) symmetrically on the first component (1) and on the second component (3), or b) on one side on a component (1,3), selected from the first component (1) and the second component (3); is trained; and / or that the gap (15) c) has at least one rounded wall (19, 19 '), and / or d) at least one flat inclined wall. Method according to one of the preceding claims, characterized in that a) the at least one rounded wall (19, 19 ') has a radius of at least 0.1 mm to at most 5 mm; preferably from at least 0.3 mm to at most 5 mm; preferably up to a maximum of 4.5 mm, preferably up to a maximum of 4 mm; preferably up to at most 3.5 mm; preferably up to a maximum of 3 mm; preferably up to a maximum of 2.7 mm; preferably from at least 0.4 mm to at most 2.6 mm; preferably from at least 0.5 mm to at most 2.5 mm; preferably from at least 0.6 mm to at most 2.4 mm; preferably from at least 0.7 mm to at most 2.3 mm; preferably from at least 0.8 mm to at most 2.2 mm; preferably from at least 0.9 mm to at most 2.1 mm; preferably from at least 1.0 mm to at most 2.0 mm; preferably from at least 1.1 mm to at most 1.9 mm; preferably from at least 1.2 mm to at most 1.8 mm; preferably from at least 1.3 mm to at most 1.7 mm; preferably from at least 1.4 mm to at most 1.6 mm; preferably 1.5 mm, preferably 0.65 mm, and / or that b) a full opening angle (a) of the gap (15) having at least one inclined wall of at least 15 ° to at most 60 °; preferably from at least 20 ° to at most 55 °; preferably from at least 30 ° to at most 45 °; preferably from at least 35 ° to at most 40 °; preferably 37 °, and / or that c) a quotient of a depth (T) of the gap (15) measured in the direction of irradiation from the irradiation surface (7) to the width (B) of the gap (15) measured in the irradiation surface (7) ) of at least 0.2, preferably of at least 0.3, preferably of at least 0.5, preferably of at least 0.6 to at most 3.2; preferably from at least 0.7 to at most 3.1; preferably from at least 0.8 to at most 3.0; preferably from at least 0.9 to at most 2.9; preferably from at least 1.0 to at most 2.8; preferably from at least 1.2 to at most 2.6; preferably from at least 1.4 to at most 2.4; preferably from at least 1.6 to at most 2.2; preferably from at least 1.8 to at most 2.0; is preferably 1.9. Method according to one of the preceding claims, characterized in that the laser beam (11) a) in a CW mode, or b) in a pulse mode, and / or c) with a beam diameter (D) of at least 0.1 mm up to a maximum of 2.5 mm; preferably up to a maximum of 2 mm; preferably up to at most 1.5 mm; preferably up to a maximum of 1 mm; preferably up to a maximum of 0.9 mm; preferably from at least 0.2 mm to at most 0.8 mm; preferably from at least 0.3 mm to at most 0.7 mm; preferably from at least 0.4 mm to at most 0.6 mm; preferably of 0.5 mm or 0.4 mm, and / or d) with a power of at least 50 W to at most 5 kW; preferably from at least 100 W to at most 5 kW; preferably up to a maximum of 4.5 kW; preferably up to a maximum of 4 kW; preferably up to a maximum of 3.5 kW; preferably up to a maximum of 3 kW; preferably up to a maximum of 2.5 kW; preferably from at least 250 W to at most 2 kW, preferably 750 W, and / or e) with a wavelength of at least 400 nm to at most 1200 nm, preferably from at least 920 nm to at most 1064 nm, in particular 532 nm, 515 nm or 450 nm , is generated, and / or f) at a feed rate of at least 0.25 m / min, preferably from at least 0.5 m / min to at most 30 m / min, preferably from at least 1 m / min to at most 25 m / min , preferably from at least 2 m / min to at most 20 m / min, preferably from at least 3 m / min to at most 17 m / min; preferably from at least 4 m / min to at most 16 m / min; preferably from at least 5 m / min to at most 15 m / min; preferably from at least 6 m / min to at most 14 m / min; preferably from at least 7 m / min to at most 13 m / min; preferably from at least 8 m / min to at most 12 m / min; preferably from at least 9 m / min to at most 11 m / min; preferably from 10 m / min or from 12 m / min, in particular in a clocked operation with a feed speed of at least 0.25 m / min, preferably from at least 0.5 m / min to at most 3 m / min, preferably up to at most 1 m / min, in particular in continuous operation with a feed rate of at least 3 m / min to a maximum of 30 m / min along the gap relative to the component arrangement. Method according to one of the preceding claims, characterized in that the laser beam (11) is generated by means of a laser which is selected from a group consisting of a diode laser, a fiber laser, an Nd: YAG laser, and a disk laser, in particular a diode-pumped one Disk laser. Method according to one of the preceding claims, characterized in that at least one component (1, 3) selected from the first component (1) and the second component (3), a) has at least one material or consists of a material that is selected is from a group consisting of nickel silver, INOX, in particular INOX 316L, copper or a copper alloy, and titanium, and / or b) is manufactured as a sintered component, in particular as an additively manufactured sintered component or as a MIM component. Method according to one of the preceding claims, characterized in that a laser weld seam (17) is produced, a) a width of the laser weld seam (17) of at least 0.1 mm measured in the irradiation surface (7) perpendicular to the longitudinal extension of the laser weld seam (17) up to a maximum of 3 mm; preferably up to at most 2.5 mm; preferably up to a maximum of 2 mm; preferably up to at most 1.5 mm; preferably up to a maximum of 1 mm; preferably up to a maximum of 0.9 mm; preferably from at least 0.2 mm to at most 0.8 mm; preferably from at least 0.3 mm to at most 0.7 mm; preferably from at least 0.4 mm to at most 0.6 mm; preferably 0.5 mm or 0.4 mm, and / or where b) a depth of the laser weld seam (17) measured in the direction of irradiation is greater than the width of the laser weld seam measured in the irradiation surface (7) perpendicular to the longitudinal extension of the laser weld seam (17) . Method according to one of the preceding claims, characterized in that the laser beam is displaced several times along the gap relative to the component arrangement. Method according to one of the preceding claims, characterized in that the first component (1) and / or the second component (3) is a component, in particular a pipe, with a wall thickness of at least 0.1 mm to at most 4 mm, preferably of at least 0.2 mm to a maximum of 3 mm is used. Component arrangement (5), with a first component (1) and a second component (3), the first component (1) and the second component (3) being joined to one another by means of laser heat conduction welding, wherein a) a laser weld seam ( 17) in a joining area (9) of the component arrangement (5) has a depth which is greater than its width and / or b) at least one component (1,3) selected from the first component (1) and the second component (3) is designed as a sintered component, in particular as an additively manufactured sintered component or as a MIM component. Component arrangement (5) according to Claim 14 , characterized in that at least one component (1,3) selected from the first component (1) and the second component (3) comprises copper or a copper alloy, or consists of copper or a copper alloy.

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