Laser welding of metals

Today, welding is an innovative assembly technique that is used in all areas. While the technique itself is widespread, some of its processes are as yet not so well known and underused. Laser welding falls into that category. In spite of its reputation as a complex process, it offers unparalleled advantages, in terms of both technique and costs.

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Laser welding of metals

Using a laser beam to weld metals involves high energy density, giving rise to a capillary made up of molten material and metallic vapours. The thermal energy transferred to the core of the capillary generates a fine and penetrating bead. It solidifies instantly, providing metallic and metallurgical continuity.

  • Welding productivity increased by up to 800 %
  • Reproducible process
  • Reduction or even elimination of the time for straightening welded pieces
  • Overall reduction of production costs
  • Heterogeneous welding (multiple materials, case-hardened parts, carbonitrided parts etc.)
  • Welding of copper and precious metals


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Laser welding of metals in detail

What is laser welding of metals ?

Metals are welded by means of an optical head (scan head etc.) coupled with a power laser.

Unlike other conventional welding processes, laser welding makes it possible to create a capillary made up of metal vapours, preceded by molten material. While welding, high energy density is transferred within the capillary, making it possible to obtain a very fine welding bead.

The molten material that makes up the welded seam solidifies instantly, allowing the metallurgical and mechanical assembly of parts. That assembly technique allows localised welding with very little deformation, and high accuracy.

It may be used in many industries such as:

  • automobile manufacturing (electric vehicles, seats, running gear, accessories, sensors, actuators etc.)
  • general engineering (pinions, tooling, housings)
  • transport (body work, stiffeners, casings, chassis, axles)
  • energy (heat exchangers, fuel rods and grilles)
  • medical engineering (prostheses, sensors, implants etc.)


  • Welding productivity increased by up to 800 %
  • Reproducible process
  • Reduction or even elimination of the time for straightening welded pieces
  • Overall reduction of production costs
  • Mechanical resistance at least equivalent to that of the base metal
  • Reduction of welding consumables
  • Great freedom in the designing of parts


Above all, the use of laser welding for metal parts improves productivity by reducing the time spent on welding and straightening the welded parts, and allows greater freedom in the designing of parts (simpler assemblies). Laser welding also helps make savings by reducing production costs and the materials consumed by the welding process. This welding method also has an effect on the quality of the assembly by offering mechanical strength that is at least equal to that of the base material, and by reducing the part deformation rate. Laser welding is also an excellent solution for joining subassemblies of dissimilar parts or treated parts (carbonitrided, case hardened etc.)

  • Welding of dissimilar materials (steel to cast iron, stainless steel to Inconel etc.)
  • Welding of precious materials
  • Welding close to delicate components
  • Welding time is reduced to a tenth
  • Reduced deformation of parts
  • Welding of parts with limited accessibility
  • Process that can be automated
  • Assembly with no filler metal

Examples of applications

Laser welding is used in different areas of business: mechanical engineering (pinions, tooling, housings), transport (body work, stiffeners, casings, chassis, axles), energy (heat exchangers, fuel rods and grilles).


Laser welding of aluminium alloys

The use of new laser technology along with a scan head makes it possible to make welds that are mechanically strong and sealed.


  • Smaller laser investment
  • Shorter cycle time
  • Full control over paths
  • Reduction of void ratio


Laser welding of cells and batteries

Laser welding of fine materials generates small welds at a high speed. Today, advancing laser technology makes it possible to weld highly reflective materials such as copper or aluminium.


  • High production speed
  • Sealed weld
  • Heterogeneous assembly
  • Full control over the application of heat


Laser welding of precious metals

Thanks to the precise management of laser welding parameters, small welds can be achieved even on highly reflective materials.
The high welding speed significantly reduces deformations, making it possible to weld watch movement parts.
Examples: welding of pins to sprocket wheels, rotors to pins, welding links and pins for watch straps, welding of precious metal appliqués on dials.


  • Fineness of the weld metal zone < 100 µm
  • Mechanical strength
  • Very low deformation


Laser welding of mechanical parts

The very low deformation due to the effect of the laser makes it possible to assemble finished parts such as components of gear boxes or cam shafts. Lasers also allow new assembly designs, for example to replace bolted assemblies in regulation components.


  • Higher welding speed
  • Process stability
  • Low deformation
  • New design possibilities
  • Mechanical resistance equivalent to that of the base metal


Welding of tubes to difufser

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Our expertise in the laser welding of metals

IREPA LASER has leading-edge equipment dedicated to the laser welding of metals in order to handle the metal welding projects of its business customers.

  • Multi-mode fibre lasers up to 6 kW and single-mode up to 750 W, quasi continuous 600 W/6 kW
  • Pulsed YAG lasers
  • CO2 lasers up to 3.5 kW
  • Optical systems, focussing from 30 to 1000 µm diameter
  • Scan heads with path repositioning
  • Numerically controlled welding machine with 3 to 4 axes
  • Robot with positioner
  • Seam tracking
  • Beam analysis system
  • Metallurgy testing laboratory
  • Characterisation resources (NDT, chemical testing, mechanical testing, SEM, X-ray diffraction, salt spray, fatigue and vibration testing etc.)
  • Failure analyses (metallurgy expertise)
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The use of laser machines for welding metals provides an effective solution for many assembly needs (macro and micro). In order to secure optimum performance, in terms of both technology and costs, it is crucial to understand and control the operating parameters.

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