EP4347170A1 - Procédé de soudure profonde au laser - Google Patents

Procédé de soudure profonde au laser

Info

Publication number
EP4347170A1
EP4347170A1 EP22724049.6A EP22724049A EP4347170A1 EP 4347170 A1 EP4347170 A1 EP 4347170A1 EP 22724049 A EP22724049 A EP 22724049A EP 4347170 A1 EP4347170 A1 EP 4347170A1
Authority
EP
European Patent Office
Prior art keywords
laser beam
welding
melting
deep
capillary
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP22724049.6A
Other languages
German (de)
English (en)
Inventor
Daniel BÖHM
Markus GRETZER
Jan-Philipp Weberpals
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Audi AG
Original Assignee
Audi AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Audi AG filed Critical Audi AG
Publication of EP4347170A1 publication Critical patent/EP4347170A1/fr
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/0604—Shaping the laser beam, e.g. by masks or multi-focusing by a combination of beams
    • B23K26/0608—Shaping the laser beam, e.g. by masks or multi-focusing by a combination of beams in the same heat affected zone [HAZ]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/0604—Shaping the laser beam, e.g. by masks or multi-focusing by a combination of beams
    • B23K26/0613—Shaping the laser beam, e.g. by masks or multi-focusing by a combination of beams having a common axis
    • B23K26/0617—Shaping the laser beam, e.g. by masks or multi-focusing by a combination of beams having a common axis and with spots spaced along the common axis
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/062—Shaping the laser beam, e.g. by masks or multi-focusing by direct control of the laser beam
    • B23K26/0626—Energy control of the laser beam
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/073—Shaping the laser spot
    • B23K26/0734—Shaping the laser spot into an annular shape
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/073—Shaping the laser spot
    • B23K26/0738—Shaping the laser spot into a linear shape
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/08—Devices involving relative movement between laser beam and workpiece
    • B23K26/082—Scanning systems, i.e. devices involving movement of the laser beam relative to the laser head
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/20—Bonding
    • B23K26/21—Bonding by welding
    • B23K26/24—Seam welding
    • B23K26/244—Overlap seam welding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/20—Bonding
    • B23K26/32—Bonding taking account of the properties of the material involved
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K31/00—Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by only one of the preceding main groups
    • B23K31/003—Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by only one of the preceding main groups relating to controlling of welding distortion
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/02—Details
    • H01M8/0297—Arrangements for joining electrodes, reservoir layers, heat exchange units or bipolar separators to each other
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2101/00—Articles made by soldering, welding or cutting
    • B23K2101/006—Vehicles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2101/00—Articles made by soldering, welding or cutting
    • B23K2101/36—Electric or electronic devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/02—Iron or ferrous alloys
    • B23K2103/04—Steel or steel alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/02—Details
    • H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
    • H01M8/0204—Non-porous and characterised by the material
    • H01M8/0206—Metals or alloys
    • H01M8/0208—Alloys
    • H01M8/021—Alloys based on iron
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Definitions

  • the invention relates to a method for deep laser beam welding of at least two joining partners according to the preamble of claim 1.
  • a bipolar plate of a fuel cell can be produced from two metal foils (e.g. steel foils) with a very thin material thickness in the range of 75 ⁇ m.
  • the two metal foils can be welded together using deep laser beam welding. This can result in very long weld seams of several meters.
  • a laser beam device generates a laser beam that has a deep welding laser beam component.
  • the laser beam moves along a joint at a feed rate.
  • the laser beam creates a vapor capillary in the material to be joined that is surrounded by a molten pool.
  • the vapor capillary moves together with the laser beam in the welding direction through the material to be joined. This takes place with the formation of a capillary flow, in which a molten metal located at the capillary front flows through molten pool channels formed on both sides of the vapor capillary towards the back of the capillary and solidifies there.
  • a further increase in the feed rate results in an irregular weld seam topography.
  • DE 197 51 195 C1 discloses a method and a device for welding by means of laser radiation. Another device for laser processing is known from DE 10 2007 046 074 A1. An optical apparatus for laser welding of a workpiece is known from DE 10 2019 210 019 A1. A method for deep laser beam welding is known from DE 10 2021 113 430 A1. DE 11 2015 003 358 T5 discloses optimizing the shape of the molten pool in a joining process. Another method for welding by means of laser radiation is known from WO 99/06173 A1. In addition, a publication by Blackbird et al from September 15, 2021 is known [T. Bautze-Scherff; D. Reitemeyer;
  • the object of the invention is to provide a method for laser beam deep welding of at least two joining partners, in which, despite the high process speed, the occurrence of the humping effect in the weld seam can be reliably avoided.
  • the object is solved by the features of claim 1. Preferred developments of the invention are disclosed in the dependent claims.
  • the invention is based on a method for deep laser beam welding of at least two joining partners.
  • a laser beam device generates a laser beam with a deep welding laser beam component.
  • the laser beam is moved along a joint at a feed rate.
  • the laser beam creates a vapor capillary in the material to be joined that is surrounded by a molten pool.
  • the vapor capillary moves together with the laser beam in the welding direction through the material to be joined. This takes place with the formation of a capillary flow, in which a molten metal located at the capillary front flows through molten pool channels formed on both sides of the vapor capillary towards the back of the capillary and solidifies there.
  • the invention is based on the fact that in conventional laser deep-penetration welding, the melt pool channels forming on both sides of the vapor capillary have a small flow cross-section.
  • the capillary flow therefore reaches a maximum flow rate in the area of the weld pool channels. Due to the small flow cross-section on the sides of the vapor capillary (i.e. the width of the melt pool minus the vapor capillary diameter), the average velocity occurring there during the capillary flow exceeds the feed rate many times over during laser beam welding, particularly in the case of materials with a small temperature difference between evaporation and solidification as well as low thermal conductivity.
  • the laser beam is additionally assigned at least one melting laser beam component.
  • the width, ie the flow cross section, of the melting channels is increased with the proportion of the melting laser beam. This reduces the flow velocity of the melting molten metal flowing through bath channels. Due to the reduced flow rates in the lateral weld pool channels, the feed rate can be significantly increased compared to the prior art without a humping effect, i.e. a periodic weld seam topography with alternating material deficits and material accumulations, occurring.
  • the flow speed around the vapor capillary can therefore be reduced by targeted beam shaping of the laser beam, as a result of which the resulting upper limit of the feed speed, above which the humping effect occurs, can be increased.
  • a closed weld seam can thus be joined at a significantly higher feed rate than is possible in comparison with the prior art, which works with a conventional round laser beam without beam shaping.
  • the formation of the molten pool is influenced by the jet shaping or jet overlapping adapted according to the invention in such a way that the flow cross section on the sides of the vapor capillary is enlarged in order to reduce the mean flow velocity occurring there during the flow around the capillary.
  • the method according to the invention is not limited to the laser beam joining of two joining partners. Rather, the method according to the invention is also suitable for the production of a composite component from several joining partners. It should also be emphasized that the method according to the invention can be used regardless of the material thickness. This means that the method can cover applications with thicker materials, for example in car body construction, as well as applications with thinner materials, for example approx. 50 ⁇ m to 200 ⁇ m, such as occur during the laser beam joining of electrochemical components of an electrochemical system. for example in the case of bipolar plates in a fuel cell, in the case of battery cell components, in the case of components of a battery module, of an overall battery system, of an electrolyzer, of a hydrogen compressor or the like.
  • the widening of the melt pool according to the invention, especially on the sides of the vapor capillary, can be achieved in a first embodiment by utilizing the lateral heat propagation through primarily conductive heat transport.
  • the melt pool can be widened by targeted melting close to the surface, preferably in the manner of heat conduction welding.
  • the flow cross section in the capillary flow is increased, as a result of which the feed rate can be significantly increased until the humping effect is reached.
  • the resulting heat field or temperature influence zone
  • the resulting thermal distortion can be kept low or controlled.
  • the beam can be shaped by adapting or increasing optical components in the equipment strand in the laser beam source, via the beam guidance in the glass fiber or directly in the processing optics.
  • beam shaping in the glass fiber with regard to direction independence are fibers with confocal arrangements, for example by guiding the radiation through a core/cladding.
  • a confocal arrangement within the meaning of the invention comprises a concentric arrangement in which the laser beam spot is divided into a radially inner core surface (hereinafter also referred to as core) and a radially outer ring or jacket surface (hereinafter also referred to as ring or Mantle designated) zueinan the concentrically aligned with the same center, with or without an intermediate geometric gap.
  • core radially inner core surface
  • ring or Mantle designated radially outer ring or jacket surface
  • the superimposed power distribution (i.e. intensity, calculated from power / area) can take place individually before and/or during the machining process due to the applied beam shaping principle.
  • the laser beam components are not concentric with each other with a common optical axis , but to each other that is offset off-centre.
  • other shapes such as ellipses, rectangles, etc. can also be used.
  • the intensity can be specified once by selecting the equipment strand consisting of laser, fiber and optics or adjusted over time during the processing process. Exemplary implementations can be:
  • the power ratio (between core and ring) is adjustable.
  • the overall performance can be adjusted once or in a time-modulated manner.
  • the core and ring can be set independently of one another before and/or during the processing process, in terms of laser power, modulation, etc.
  • DOE diffractive optical elements
  • a fixed geometry specification with limited power distribution between ring and core can be modulated once or over time by the laser source with absolute power specification.
  • the beam axes of the laser beam components can be shifted relative to one another by the design of the element, for example by defocusing.
  • the laser beam and/or the laser beam components can each be implemented as an omnidirectional beam.
  • the deep-welding laser beam component and the melting laser beam component can be aligned in a superimposed beam formation in a concentric arrangement, specifically in a core/cladding guide of the laser beam.
  • a radially inner core with, in particular, a circular cross-sectional area forms the deep-welding laser beam component and a radially outer, circular-annular shell in cross-section forms the melting laser beam component.
  • the diameter ratio of the two laser beam components and/or the power ratio of the two laser beam components can be adjusted to the process speed in the concentric arrangement, so that there is a sufficiently large melt pool channel for the capillary flow.
  • the ratio of the two beam diameters is particularly preferably: 2.5 ⁇ d2/di ⁇ 10, and most preferably 2.5 ⁇ d2/di ⁇ 4.
  • a single-mode laser is preferred, with which such small focus diameters can be generated.
  • the imaging is preferably carried out using scanner optics, with an imaging ratio between 1 and 6, in particular between 2 and 4.
  • the power of the deep welding part of the laser beam can be changed by the process control in direct proportion to the feed rate. For example, if the feed rate is increased from 800 mm/s by a factor of 1.5 to 1200 mm/s, the power of the deep welding laser beam component can also be increased by the same factor. Feed rates of up to 1500 mm/s, in particular 2000 mm/s, can be achieved by means of the invention.
  • the power of the melting laser beam portion ie in the annular, radially outer shell
  • the melting temperature is reached in the area of the melting laser beam, but not the vapor temperature of the material to be joined (e.g. steel).
  • the laser beam can have a deep-welding laser beam component and at least one melting laser beam component that runs ahead in the welding direction.
  • At least two leading melting laser beam components can preferably be assigned to the deep welding laser beam component.
  • the deep-welding laser beam component can move on a longitudinal axis of the joint, while the two melting laser beam components are each offset by a transverse offset on both sides of the longitudinal axis of the joint.
  • the transverse center distance a2 between the two leading melting laser beam components can preferably correspond to at least the focus diameter di of the deep welding laser beam component.
  • the distance between the inner sides of the two leading melting laser beam portions facing transversely to the longitudinal axis of the joint can be dimensioned smaller than the focal diameter of the trailing deep welding laser beam portion. This ensures an overlap between the partial melt pools of the three laser beam components.
  • the focus diameter of the deep welding laser beam component can be in a range of, for example, 40 ⁇ m to 100 ⁇ m, specifically in particular at 50pm.
  • a single-mode laser can preferably be used for this purpose, with which such small focus diameters can be generated.
  • the imaging is preferably carried out via a scanner optics, and with an imaging ratio between 1 and 6, in particular between 2 and 4.
  • exactly one melting laser beam component can be provided, which is aligned in longitudinal alignment with the trailing deep welding laser beam component in the welding direction.
  • two procedural forms are covered by the invention:
  • the leading melting laser beam component can have a power that is reduced in comparison to the power of the deep welding laser beam component to a value below the deep welding threshold.
  • the melting portion of the laser beam therefore performs heat conduction welding, in which only melting close to the surface takes place, but without evaporation of the material to be joined.
  • the laser beam spots of the two laser beam components can have such focal diameters that the two spots at least touch or partially overlap.
  • the midpoint-longitudinal distance between the two laser beam components is greater than zero.
  • the diameter ratio of the two laser beam components can be determined analogously to the concentric arrangement.
  • the power of the two laser beam components can also be adjusted in analogy to the concentric arrangement. 2.
  • the leading melting laser beam component can be designed in such a way that it does not conduct heat conduction welding, but performs deep welding.
  • the diameter ratio d2/di at the two laser spots can be at least close to 1.
  • the center distance between the two laser beam components can be set in such a way that the lateral temperature gradient is smaller than in comparison to a single beam or in comparison to two laser beam components with a distance that is too large.
  • the process control can set the center distance and the power of the two laser beam components, preferably in such a way that the width of the respective melt pool channel increases due to the lower temperature gradient.
  • the laser beam components arranged one behind the other in a longitudinal alignment can form a line focus. This extends over a focal length along the welding direction. The width of the line focus corresponds to the focus diameter of the laser beam components.
  • the beam shaping within the scope of the invention can be generated by optical elements in the laser beam device, for example a prism, a diffractive or refractive optical element or other features in the processing optics, preferably in the collimated beam path between the collimating lens and the focusing lens.
  • optical elements in the laser beam device for example a prism, a diffractive or refractive optical element or other features in the processing optics, preferably in the collimated beam path between the collimating lens and the focusing lens.
  • the beam splitting can be generated, for example, using parts or prisms, with the line focus being generated using cylindrical lenses, for example.
  • the method can be used in particular for the laser beam joining of components in an electrochemical system, such as battery cell components, components of a fuel cell, a battery mo- ] l duls, an overall battery system, an electrolyzer, a hydrogen compressor or the like.
  • sheet metal parts lying one above the other can be connected to one another with a material thickness in particular in the range of, for example, 50 ⁇ m to 250 ⁇ m, or in the range of, for example, 250 ⁇ m to 500 ⁇ m.
  • other applications are also possible, for example in the laser beam joining of sheet metal parts lying one on top of the other with a material thickness in the range of, for example, 250 ⁇ m to 500 ⁇ m.
  • the method can also be used in the laser beam joining of components in body construction.
  • superimposed sheet metal parts with a material thickness of, for example, greater than 0.5 mm, in particular in the range from 0.5 mm to 5 mm, particularly preferably in the range from 0.5 mm to 3 mm, can be connected to one another as joining partners.
  • 1 to 4c are views that illustrate a welding process according to a first embodiment
  • FIGS. 5 to 7 each show views based on which beam formations are illustrated according to further exemplary embodiments.
  • the method according to the invention is used to produce a component composite of two or more sheet metal parts.
  • the process can be used regardless of the material thickness.
  • a laser beam device is shown in FIG. 1, by means of which two joining partners 1, 3 are welded to one another in a deep-penetration welding process.
  • the two joining partners 1, 3 are, for example, thin steel foils.
  • the joining partners 1, 3 can, for example, be components of an electrochemical system, such as a fuel cell or a battery cell, or components of a battery module, an overall battery system, an electrolyser or the like.
  • the invention is not limited to special material strengths of the joining partners 1, 3.
  • the joining partners 1, 3 lying one above the other can have a material thickness in particular in the range of, for example, 50 ⁇ m to 250 ⁇ m, or in the range of, for example, 250 ⁇ m to 500 ⁇ m.
  • other applications are also possible, for example in the laser beam joining of superimposed sheet metal parts with a material thickness in the range of, for example, 250 ⁇ m to 500 ⁇ m.
  • the method is not limited to the laser beam joining of components of an electrochemical system.
  • the method can be used in any application, for example in laser beam joining of components in body construction.
  • joining partners 1, 3 with a material thickness of, for example, greater than 0.5 mm, in particular in the range from 0.5 mm to 5 mm, particularly preferably in the range from 0.5 mm to 3 mm, are connected to one another.
  • the laser beam device In the deep welding process, the laser beam device is moved at a feed speed v in a welding direction, as a result of which a weld seam 4 is formed, which connects the two joining partners 1, 3 to one another in a fluid-tight manner.
  • the laser beam device has processing optics 5 with an optical fiber 7 in FIG.
  • the processing optics 5 consists of collimating optics 7 and focusing optics 9 .
  • Superimposed beam shaping of the laser beam 10 takes place in the processing optics 5.
  • a deep welding laser beam component 11 and a melting laser beam component 13 are aligned in a concentric arrangement by means of the superimposed beam shaping, as can be seen in FIGS.
  • a core/cladding guide of the laser beam 10 is implemented, in which a radially inner core with a circular cross-sectional area forms the deep-welding laser beam portion 11 and a radially outer cladding with a circular cross-section forms the melting laser beam portion 13.
  • a vapor capillary 15 which is surrounded by a molten pool 17 , is produced in the joining partner tool by means of the deep welding laser beam portion 11 in the welding process according to FIG. 2 .
  • the vapor capillary 15 moves with the laser beam 10 in the welding direction through the material to be joined. This results in a capillary flow 17 indicated by arrows in FIG. 3, in which a molten metal located on the capillary front 19 flows via molten bath channels 21 formed on both sides of the vapor capillary 15 in the direction of the capillary back 23 and solidifies there.
  • the melting laser beam component 13 With the help of the melting laser beam component 13, there is a targeted melting close to the surface in the manner of heat conduction welding. This creates a widening of the melt pool, in which the width b (FIG. 3) and thus the flow cross section of the melt pool channels 21 increase. In this way, the flow rate of the molten metal flowing through the melt pool channels 21 is reduced. Due to the reduced flow velocities in the lateral melt pool channels 21, the feed rate can be significantly increased compared to the prior art without a humping effect occurring, ie a periodic weld seam topography with alternating material deficits and material accumulations.
  • the laser beam 10 and the two laser beam components 11, 13 are each implemented as an omnidirectional beam.
  • the focus diameter di of the deep welding laser beam portion 11 can be 75 ⁇ m.
  • the power P2 of the melting laser beam portion 13 is reduced in FIGS. 1 to 4 in comparison to the power Pi of the deep welding laser beam portion 11 to a value below a deep welding threshold.
  • the melting temperature is therefore reached with the melting laser beam portion 13, but not the vapor temperature of the material to be joined.
  • the power P2 of the melting laser beam portion 13 is set in such a way that only the component surface is melted. When measuring the power P2 of the melting laser beam portion 13, the thermal influence is taken into account by the power Pi of the deep welding laser beam portion 11.
  • Examples of beam shaping in the glass fiber are fibers with a concentric arrangement without or with a geometric distance (ie annular gap 30) between core and ring.
  • the diameter ratio d2/d1 is variable in the case of the concentric arrangement. In this case, the following applies: d2>d1 (d2: outside diameter of the ring, d1: outside diameter of the core), where preferably the following applies: 1 ⁇ d2/d1 ⁇ 20.
  • the geometric distance (ie the annular gap 30) is described as ds ⁇ d1>0 and d2>ds (ds: annular gap outer diameter).
  • the power ratio P2/P1 can be adapted to the process and primarily to the process speed, so that a sufficiently large melt pool channel 21 is formed for the capillary flow.
  • any configurable matrix arrangement is conceivable: For example, in FIG. 4c, the core and the ring are no longer aligned concentrically with one another, but offset from one another, with the core still being completely surrounded by the ring.
  • the configurations shown in FIGS. 4a to 4c are based on the approach that the molten pool 17 is widened by the outer radiation portion 13 by near-surface melting (heat conduction welding regime).
  • all beam configurations can be generated by optical elements such as a prism, a diffractive or refractive optical element or other characteristics in the processing optics, preferably in the collimated beam path between the collimating lens and the focusing lens.
  • optical elements such as a prism, a diffractive or refractive optical element or other characteristics in the processing optics, preferably in the collimated beam path between the collimating lens and the focusing lens.
  • FIGS. 5 to 7 Alternative beam shapes according to further exemplary embodiments are indicated below with reference to FIGS. 5 to 7.
  • the laser beam components 11, 13 are each realized as individual omnidirectional beams, of which only the laser spots formed at the joint are shown in FIGS. 5 to 7.
  • a second exemplary embodiment is indicated in FIG. is shared. Accordingly, the deep-welding laser beam component 11 moves on a longitudinal axis x of the joint, while the two leading melting laser beam components 13 are each offset on both sides by a transverse offset from the longitudinal axis x of the joint.
  • the midpoint-longitudinal distance ai between the trailing deep welding laser beam portion 11 and the two leading melting laser beam portions 13 is greater than zero and dimensioned such that the part melt pools generated by the laser beam portions 11, 13 merge into a common melt pool.
  • the laser beam components 11, 13 can at least touch tangentially with their laser spots or partially overlap one another.
  • the mid-point transverse distance a2 between the two leading melting laser beam portions 13 can at least correspond to the focus diameter di of the deep-welding laser beam portion 13 .
  • a distance a3 between the inner sides of the two melting laser beam portions 13 facing one another can be smaller than the focus diameter di of the deep welding laser beam portion 11. In this way, there is an overlap between the partial melt pools of the two leading melting laser beam portions 13 and the deep welding laser beam portion 11 ensured.
  • FIG. 6 a view corresponding to FIGS. 4 and 5 indicates a third exemplary embodiment, in which the laser beam 10 is divided by beam shaping into a lagging deep-welding laser beam portion 11 and a leading melting laser beam portion 13.
  • the two laser beam components 11, 13 are arranged one behind the other in a longitudinal alignment.
  • the melting laser beam portion 13 in FIG. 6 can have a power P2 which, in comparison to the power Pi of the deep welding laser beam portion 11, is reduced to a value below a deep welding threshold.
  • P2 the power of the deep welding laser beam portion 11
  • a lateral heat input W results from primarily conductive heat transport.
  • the leading melting laser beam component 13 can have a power P2, which does not allow heat conduction welding, but deep welding.
  • the diameter ratio d2/di can be at least close to 1.
  • the center point-longitudinal distance ai between the two laser beam components 11, 13 can be set in such a way that the lateral temperature gradient is smaller than in comparison to a single beam or two laser beam components that are too far apart.
  • the process control of the laser beam device can set the longitudinal center distance ai and the powers Pi, P2 in such a way that the width of the respective melt pool channel 21 increases due to the low temperature gradient.
  • FIG. 7 shows a fourth exemplary embodiment, in which the two laser beam components 11, 13 arranged one behind the other in longitudinal alignment form a line focus 29. This extends over a focal length I along the welding direction, with its width corresponding to the focal diameters di, d2 of the laser beam components 11 , 13 .
  • the power Pi of the trailing deep welding laser beam portion 11 is dimensioned in such a way that a deep welding process is made possible.
  • a power distribution along the longitudinal axis x is possible in the line focus 29 .
  • Line focus length b Melt pool channel width ai Longitudinal center distance a2 Transverse center distance a3 Distance v Feed speed

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Plasma & Fusion (AREA)
  • Manufacturing & Machinery (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Laser Beam Processing (AREA)

Abstract

L'invention concerne un procédé de soudure profonde au laser d'au moins deux partenaires de jonction (1, 3). Un dispositif à faisceaux laser génère un faisceau laser (10) comprenant un composant de faisceau laser de soudure profonde (11) qui est déplacé le long d'un point de jonction à une vitesse d'avance (v). Le composant de faisceau laser de soudure profonde (11) génère un tube capillaire (15) dans le matériau partenaire de jonction, ledit tube capillaire étant entouré d'un bain de fusion (17) et se déplaçant à travers le matériau de partenaire de jonction dans la direction de soudure conjointement avec le faisceau laser (10), formant ainsi un flux capillaire en circulation (18) au moyen duquel le métal fondu qui peut se trouver au niveau du front capillaire (19) s'écoule dans la direction de la face arrière capillaire (23) par l'intermédiaire de canaux de bain de fusion (21) formés des deux côtés du tube capillaire (15) ou se solidifie. Selon l'invention, au moins un composant de faisceau laser de fusion (13) est en outre attribué au faisceau laser (10), ledit composant de faisceau laser de fusion étant utilisé pour augmenter la largeur (b), c'est-à-dire la section transversale de flux, des canaux de bain de fusion (21), la vitesse du flux de métal fondu s'écoulant à travers les canaux de bain de fusion (21) étant ainsi réduite.
EP22724049.6A 2021-05-25 2022-04-21 Procédé de soudure profonde au laser Pending EP4347170A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102021113430.7A DE102021113430A1 (de) 2021-05-25 2021-05-25 Verfahren zum Laserstrahltiefschweißen
PCT/EP2022/060476 WO2022248128A1 (fr) 2021-05-25 2022-04-21 Procédé de soudure profonde au laser

Publications (1)

Publication Number Publication Date
EP4347170A1 true EP4347170A1 (fr) 2024-04-10

Family

ID=79021251

Family Applications (1)

Application Number Title Priority Date Filing Date
EP22724049.6A Pending EP4347170A1 (fr) 2021-05-25 2022-04-21 Procédé de soudure profonde au laser

Country Status (5)

Country Link
US (1) US20240165742A1 (fr)
EP (1) EP4347170A1 (fr)
CN (1) CN117203016A (fr)
DE (1) DE102021113430A1 (fr)
WO (1) WO2022248128A1 (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102021113430A1 (de) 2021-05-25 2022-01-20 Audi Aktiengesellschaft Verfahren zum Laserstrahltiefschweißen
DE102022103167A1 (de) * 2022-02-10 2023-08-10 Trumpf Laser- Und Systemtechnik Gmbh Verfahren zum Laserschweißen einer Bipolarplatte für eine Brennstoffzelle, mit zeitlich zyklisch variierender Leistungsdichteverteilung im Bereich des Schmelzbads
DE102022210061A1 (de) 2022-09-23 2024-03-28 Robert Bosch Gesellschaft mit beschränkter Haftung Vorrichtung und Verfahren zum Laserstrahlschweißen von Bauteilen

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19751195C1 (de) 1997-08-01 1999-04-29 Fraunhofer Ges Forschung Verfahren und Vorrichtung zum Schweißen mittels Laserstrahlung
US6444947B1 (en) 1997-08-01 2002-09-03 Fraunhofer-Gesellschaft Zur Forderung Der Angewandten Forschung E.V. Method and device for laser beam welding
DE102007046074A1 (de) 2007-09-24 2009-04-09 Trumpf Laser- Und Systemtechnik Gmbh Vorrichtung und Verfahren zur Laserbearbeitung
DE102011016579A1 (de) * 2011-04-07 2011-11-17 Daimler Ag Verfahren und Vorrichtung zum Laserstrahlschweißen
US20160016259A1 (en) 2014-07-21 2016-01-21 Siemens Energy, Inc. Optimization of melt pool shape in a joining process
CN107848069B (zh) * 2016-07-15 2019-10-08 可利雷斯股份有限公司 激光处理装置和方法
DE102016220067B4 (de) * 2016-10-14 2023-09-21 Trumpf Laser Und Systemtechnik Gmbh Verfahren zum Tiefschweißen eines Werkstücks, wobei eine verkippte Dampfkapillare mittels zweier Laserstrahlen erzeugt wird
WO2019129917A1 (fr) * 2017-12-29 2019-07-04 Corelase Oy Appareil et procédé de traitement au laser
KR102639299B1 (ko) * 2018-07-18 2024-02-20 삼성에스디아이 주식회사 이차전지 및 그 용접방법
JP7449863B2 (ja) * 2018-09-04 2024-03-14 古河電気工業株式会社 溶接方法および溶接装置
DE102019210019B4 (de) 2019-07-08 2021-06-10 Trumpf Laser- Und Systemtechnik Gmbh Optische Apparatur zum Laserschweißen eines Werkstücks, Verfahren zum Laserschweißen eines Werkstücks mittels mehrerer Teilstrahlen sowie Verwendung einer optischen Apparatur zum Laserschweißen
DE102021113430A1 (de) 2021-05-25 2022-01-20 Audi Aktiengesellschaft Verfahren zum Laserstrahltiefschweißen

Also Published As

Publication number Publication date
WO2022248128A1 (fr) 2022-12-01
CN117203016A (zh) 2023-12-08
DE102021113430A1 (de) 2022-01-20
US20240165742A1 (en) 2024-05-23

Similar Documents

Publication Publication Date Title
EP4347170A1 (fr) Procédé de soudure profonde au laser
EP2310163B1 (fr) Procédé d'orientation excentrée d'un faisceau laser par rapport à un axe de buse et de découpage oblique, tête d'usinage laser et machine d'usinage laser correspondantes
DE102007038502B4 (de) Verfahren zum Fügen von mindestens zwei Werkstücken mittels eines Laserstrahls
EP4045223B1 (fr) Procédé de soudage au laser pour réaliser des assemblages en coin de parties de pièces
DE102015104411B4 (de) Laserstrahlfügeverfahren und Laserbearbeitungsoptik
WO2021005061A1 (fr) Appareil optique et procédé de soudage au laser d'une pièce, comprenant plusieurs faisceaux partiels présentant une zone centrale et une zone annulaire dans le profil de faisceau
EP0262363A2 (fr) Procédé et dispositif pour la fabrication en continu de corps tubulaires à l'aide d'une soudure de joint longitudinal par laser
WO2009000259A1 (fr) Procédé et dispositif pour assembler par soudure des pièces métalliques à paroi épaisse
WO2018219710A1 (fr) Procédé de soudage profond d'une pièce comportant une répartition de la puissance laser à plusieurs foyers
EP2429755A1 (fr) Dispositif et procédé permettant l'usinage périphérique au laser d'un cordon de matière
DE102014203025A1 (de) Verfahren zum Laserstrahlschweißen und Schweißkopf
EP4017674A1 (fr) Procédé d'oxycoupage au moyen d'un faisceau laser
EP1479506B1 (fr) Procédé de soudage pour des plastiques structurés
DE102016220067A1 (de) Verfahren zum Tiefschweißen eines Werkstücks, wobei eine verkippte Dampfkapillare mittels zweier Laserstrahlen erzeugt wird
WO2023285084A1 (fr) Dispositif optique de soudage pour le soudage au laser de pièces, avec réglage flexible du nombre et de la distance de spots laser par des lentilles cylindriques, et utilisations d'un tel dispositif optique de soudage
DE102015212284A1 (de) Vorrichtung und Verfahren zum pulverbasierten Laser-Auftragsschweißen
WO2021175555A1 (fr) Procédé de soudage laser de deux pièces revêtues
EP1491279A1 (fr) Procédé de soudage multifocal et appareil de soudage
DE102022101092A1 (de) Verfahren zur Laserbearbeitung eines Werkstücks mit verringerter Intensitätslücke
WO2023061831A1 (fr) Procédé d'usinage laser d'une pièce présentant un écart d'intensité réduit
DE102018127649A1 (de) Verfahren zum Laserschweißen mit stabilem Schmelzbad und Laserbearbeitungsvorrichtung
DE102021126755A1 (de) Verfahren zur Laserbearbeitung eines Werkstücks, mit verringerter Intensitätslücke
DE102021126754A1 (de) Verfahren zum Laserschweißen eines Werkstücks mit schnellem Wechsel zwischen Schweißzonen mit unterschiedlichen zu schweißenden Materialien
WO2023006611A1 (fr) Procédé de découpe au laser d'une pièce, avec un minimum d'intensité étendu sur l'épaisseur de la pièce, au centre du profil d'intensité du faisceau laser
WO2009124765A1 (fr) Procédé de production d'au moins deux structures de tôle multidimensionnelles d'une carrosserie de véhicule au moyen d'un faisceau laser présentant un angle de focalisation compris entre 2 et 7°

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20240102

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR