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
  • B23K26/14—Working by laser beam, e.g. welding, cutting or boring using a fluid stream, e.g. a jet of gas, in conjunction with the laser beam; Nozzles therefor
• • 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
  • B23K26/14—Working by laser beam, e.g. welding, cutting or boring using a fluid stream, e.g. a jet of gas, in conjunction with the laser beam; Nozzles therefor
  • B23K26/1462—Nozzles; Features related to nozzles
  • B23K26/1464—Supply to, or discharge from, nozzles of media, e.g. gas, powder, wire
  • B23K26/147—Features outside the nozzle for feeding the fluid stream towards the workpiece
• • 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
  • B23K2101/00—Articles made by soldering, welding or cutting
  • B23K2101/34—Coated articles, e.g. plated or painted; Surface treated articles
  • B23K2101/35—Surface treated articles
• • 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
  • B23K2103/08—Non-ferrous metals or alloys
• • 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
  • B23K2103/50—Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26

Definitions

• the invention relates to a method for welding with laser radiation or the like.
• high-energy radiation in which two workpieces lying against one another have a coating between them with a vaporization point below the melting point of the workpiece material, and in which a gas flow directed at the processing point is used.
• craters or holes are created in the processing area, which lead to the destruction of the weld seam. If the eruption force of the evaporated surface coating is no longer sufficient to penetrate the cooling melt, pores remain in the weld seam, which is therefore defective.
• coated workpieces can be welded gaplessly and with degassing through the steam apillary of the processing point.
• Flushing the processing point with a protective or working gas, a gas flow promoting the degassing of the vaporized coating from the steam capillaries of the processing point is used.
• a gas flow is used, is employed with a 'protection or working gas additionally put into a purging the Hä ⁇ is important.
• This gas flow can be directed and dimensioned such that degassing of the vaporized coating or other pore-forming components present in the material is achieved from the vapor capillaries.
• the gas flow in its capacity as an additional gas flow, allows the conventional purging of the work station to continue, for example in order to influence the coupling of energy and / or to shield the work station from the ambient atmosphere.
• the gas flow creates a negative pressure in the region of the. Processing point so that the gases or coating vapors flowing into the steam capillary are quickly pumped off or removed. The proportion of gaseous constituents which penetrate into the melt is drastically reduced, so that an eruptive melt expulsion can be avoided.
• the gas flow is directed at least essentially parallel to the workpiece surface. It is therefore not used coaxially with the laser radiation, as in the known method described above, but practically perpendicular to it.
• the workpieces are welded through and degassed with gas flow at both ends of the steam capillaries.
• the vapor a pillar can be degassed at both ends and thus considerably
• the procedure is expediently such that the gas flow acting on the laser beam side of the workpieces is stronger than the laser beam side.
• the stronger gas flow on the side of the workpiece facing away from the laser beam increases the degassing effect, which can be used to keep the degassing of the same size on both sides, for example with workpieces of the same thickness.
• the gas of the gas flow has a flow velocity which causes the steam capillary to expand.
• the gas flow tears open the steam capillary, in particular on the side of the workpieces facing away from the jet, or, due to its flow behavior, contributes to faster removal by the melt, particularly on the side of the workpieces facing away from the jet.
• An essential further procedural measure in particular in connection with the use of the gas flow promoting the degassing, is that the surface tension of the melt is reduced by means of increased energy coupling and / or by chemical gas reaction and / or the diameter of the steam capillary is increased.
• the reduction in the surface tension of the melt promotes segregation of the gases which have penetrated into the melt and thus a reduction in the entrainment effect of the gases when they escape from the melt.
• the Increasing the diameter of the steam capillary also increases the degassing rate.
• a device for carrying out one of the above-described methods is characterized in that during welding there is at least one nozzle which is directed at a flat angle to the workpieces and has an end which is exactly parallel to the workpiece surface. With the help of the surface-parallel end, a very precisely directed gas flow parallel to the workpiece surface can be generated, so that the desired degassing effect is optimal.
• FIG. 1 shows a cross-sectional view through two workpieces to be welded to one another in the region of a processing point
• Fig.2 is a plan view of the processing point of Fig.l.
• the workpieces 1 and 2 shown in FIG. 1 are sheets which are coated on their outer sides, for example galvanized. This results in a coating 3 located between the workpieces 1, 2 arranged without gaps
• the outer sides 10, 10 'of the workpieces 1, 2 are each provided with layers 3''.
• the steam capillary 7 has ends 1 ', 1' 'which are open to the outside because the workpieces 1, 2 are welded through. Because of the energy coupling with the laser beam 11 mainly in the area of the end 7 'of the steam capillary 7, this end 7' is larger in diameter than the opposite end 7 ''.
• FIG. 1 also shows a nozzle 14 with which a protective or working gas 6 can be fed to the processing point 4, for example in order to influence the coupling of energy or to shield the processing point 4.
• the setting of the strength of the gas flow 5, 5 ' is matched to the respective requirements, for example to the thickness of the coating and thus to the steam quantities of the coating 3' or the feed rate and the material of the coating 3.
• Fig.l also shows that the strength of the gas flow, in particular the gas flow 5 'can be adjusted so that the steam capillary 7 is expanded.
• the extension in question is designated 18.
• the strength of the gas flows can be different on the lo, lo 'sides. 1 shows a stronger gas flow 5 'on the side 10' by means of a thicker arrow, in order to degas the steam capillary more strongly through its end 7 ', which is advantageous because of its smaller diameter if the degassing through the two ends 7 , 7 'should be the same size.
• the protective or working gas 6 fed through the nozzle 14 is, for example, an inert gas, such as helium, or an active gas, such as carbon dioxide. These gases can also be used for the gas flow 5.5 '. However, it is generally advisable to use an especially inexpensive gas for the gas flow 5, 5 ', since the consumption is greater as a result of the greater flow rate than when the processing point 14 is flushed with a protective or working gas 6 .
• FIGS shows the side view of two workpieces 1, 2 designed as galvanized sheets which have bevels 1 ', 2' with which they abut one another, so that as a result there is an enclosed coating 3, which is shown in FIGS is symbolized by a reinforced line.
• a laser beam 11 is used which is directed vertically to the folds 1 ', 2' and whose beam spot width determines the width of the weld seam 13.
• gas flow nozzles 19 which protrude close to the folds 1 ', 2'.
• the ends 19 ' are directed parallel to the surface of the folds 1', 2 ', so that gas flows 5, 5' parallel to the workpiece surface arise in the feed direction 8 of the workpieces 1, 2 and the effects described above in the region of the steam capillary 7, not shown here produce.
• 3a show an exemplary embodiment of a lap joint of galvanized sheets, which is welded without a gap.
• Such lap joints are used, for example, in body and container construction.
• body shop there are fully galvanized engine sub-carriers, spring domes and other chassis parts or welds in the area of the gutter.
• carbon dioxide or a mixed gas with oxygen components is used as the gas for the gas flow 5, 5 '.
• Mixed gas is understood here as a mixture of inert and active gases.
• the method according to the invention is used for welding surface-coated workpieces, eg. B. galvanized sheets.

Landscapes

• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Engineering & Computer Science (AREA)
• Plasma & Fusion (AREA)
• Mechanical Engineering (AREA)
• Laser Beam Processing (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6387061

Family Applications (1)

Country Status (3)

Cited By (8)

Families Citing this family (5)

Citations (5)

Family Cites Families (2)

• 1989
  • 1989-08-15 DE DE3926781A patent/DE3926781A1/de active Granted
• 1990
  • 1990-08-11 WO PCT/DE1990/000622 patent/WO1991002621A1/de unknown
  • 1990-08-11 AU AU61588/90A patent/AU6158890A/en not_active Abandoned

Patent Citations (5)

Non-Patent Citations (2)

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