KTW High-Vacuum Laser Welder:

Precision, Highest Weld Quality, and Cost Effectiveness Combined

Enjoy the benefits of two sophisticated technologies in one. Vacuum laser welding offers a precise and controlled, low-stress way of joining a large number of different materials including oxygen-affine and refractory metals. Suitable for a wide range of applications, even sensorics and other sensitive components. With an affordable price tag to boot. 

Laser = progress at the speed of light

There is hardly any technology that has made as much progress in recent years and decades as laser technology.

  • the available power and brilliance of laser sources and thus the possible fields of application are constantly increasing
  • the number of available laser types and the associated wavelengths are increasing, which means that more and more materials can be processed or the energy absorption can be optimised
  • the quality and design of optical elements is constantly increasing and with it the ability to modify and manipulate/control the laser beam.

The energy of the coherent light beam already has a firm place in many industrial applications (cutting, welding, structuring, and marking). But laser technology is one of the technologies of the future and the diverse research and developments will not let the stream of innovations stop over the next few years.

KTW Technology GmbH is also making a contribution to this progress with the innovative laser beam welding of metallic materials in a vacuum. Here, the advantages of laser welding are combined with the advantages of vacuum welding. The result is a new, flexible welding process that can meet even the highest quality requirements.

The Future of Welding, Available to You Now

The KTW Technology High-Vacuum Laser Beam Welder combines the latest in laser-welding technology with the benefits of vacuum welding.

Thanks to great strides that have been made in laser technology in recent years, it has become perfectly suited for the application in welding. Laser welding combines the ability to use precisely timed and targeted energy output with low power consumption and reduced mechanical and electro-mechanical stress on the target material. Well established as a method for joining metals, improvements in power, brilliance, quality, design, and control have opened up laser welding to additional fields of application and materials, including - increasingly - plastics.

Using it in a vacuum reduces the already low material and seam reactivity of laser welding even further. It results in welding seams with an unparalleled precision, purity, homogeneity, and durability.

Here at KTW Technology, we strive to make this brilliant technology available to our clients with the world’s only cost-efficient laser-based welding solution under high vacuum.

Combination of processes has advantages

The advantages of laser beam welding are widely known and have led to a broad application of this technology for welding metals and increasingly also plastics. The laser beam is particularly convincing due to the high energy input without mechanical and electro-mechanical stress for the component and at the same time low energy consumption.

Welding under vacuum increases the quality of the weld seam by avoiding unwanted reactions of the melt with the surrounding atmosphere. The quality of the weld correlates with the "quality" of the vacuum. In addition to the processing quality of the welding chamber (closed space), it is above all the provision of thermal energy that limits the achievable vacuum level.

(Nahtbild einer Laserstrahlschweißung im Hoch-Vakuum)

Process advantages at a glance:

The combination of laser beam and vacuum welding technology not only combines the advantages of both processes, but also creates further significant benefit aspects - true to the motto: "The whole is more than the sum of the individual parts!"

Laser beam welding in a vacuum sets new standards for the sophisticated welding of demanding and sensitive materials and components.

Welding with laser beamWelding in vacuum
  • High energy density in the focal position of the laser beam; energy distribution over beam cross-section can be manipulated with optical elements.
  • Thermal welding energy through absorption of the radiation energy in the component (degree of absorption depends on wavelength and material)
  • No mechanical stress or vibrations on the component, sensitive electronic components can be welded without problems
  • Precise, repeatable and fast positioning of the laser beam via optics or CNC axes
  • Simple and loss-free guidance of the laser beam from the source to the welding spot (mirror, light guide, etc.), feed-throughs possible
  • High welding depths depending on laser power and feed speed (e.g. steel up to 50mm)
  • Very low heat-affected zone, especially with pulsed laser beam, reduces stress and crack tendency
  • Adjustment of the vacuum level depending on process/material requirements possible (cost optimisation of the pump station)
  • Pore-free weld seam, as vacuum supports the outgassing of the molten metal
  • No unplanned chemical reactions of melt and atmosphere
  • No shielding gases required
  • No foreign inclusions in the weld seam
  • Strength of the weld seam close to the strength of the base material
  • Enables welding of oxygen affine or refractory metals (e.g. titanium, tungsten)
  • Reduced spattering (less post-processing)
  • Process-safe sealing/welding of vacuumed hollow bodies (e.g. sensor housings)
Combination of laser beam and vacuum welding
  • Oxygen-affine and refractory metals can be welded with laser beam
  • Increase in welding depth achievable with the same laser power or lower laser power required
  • Tendency to form pores at large welding depths is significantly reduced, homogeneous welding pattern
  • Vakuumkammer kann gleichzeitig Funktion des Laserschutzes übernehmen
  • As an alternative to the vacuum, an atmosphere can also be specifically set
  • Low investment and operating costs compared to available alternative technologies

Benefits of the KTW High-Vacuum Laser Welder Technology

The strength of this welding method lies in the combination of two different technologies. Laser beam welding and welding in a vacuum each offer advantages over electron beam welding on their own. Combining the two creates synergistic benefits that result in a whole that is greater than the sum of its parts.

Control and Precision

KTW laser beam welders allow for precise, repeatable, fast, and easy positioning of the laser beam on the target via CNC axes. In addition, manipulation of the energy distribution across the beam is similarly uncomplicated. This results in easy and lossless delivery of welding energy from the source to the target. In short, high-vacuum laser welding offers a high level of automation, precision, and repetition accuracy. Furthermore, the beam wavelength and vacuum level are adjustable according to material needs, absorption rate, and process requirements, with a maximum of 10-5mbar. Welding in a vacuum also eliminates the need for shielding-gas use, though the possibility to set specific atmospheres or introduce inert gasses also exists.

Darüber hinaus sind die Wellenlänge des Strahls und das Vakuumniveau je nach Materialbedarf, Absorptionsrate und Prozessanforderungen einstellbar, mit einem Maximum von 10-5 mbar. Das Schweißen im Vakuum macht auch die Verwendung von Schutzgas überflüssig, obwohl auch die Möglichkeit besteht, bestimmte Atmosphären einzustellen oder Schutzgase einzuführen.

High Purity and Durability

Welding in a vacuum encourages the outgassing of the molten material and prevents unplanned chemical reactions of the melt and its surrounding atmosphere. It also inhibits foreign inclusions in the weld seam and the tendency to form pores at large welding depths is significantly reduced. Furthermore, high-vacuum laser welding is impervious to magnetic and electromagnetic fields. The result: a homogeneous welding pattern with a seam strength close to the base material.

Material Conservation

Laser welding delivers high energy density at the focal point. The weld is initiated via absorption in the target material, which produces no mechanical stress or vibrations. Additionally, this method keeps the heat-affected zone very small, especially when using laser pulses, and reduces the risk for tension, spatter, and cracking. Less stress, in turn, reduces the need for post-processing.

Efficiency and Economy

Vacuum laser welding is able to produce high welding depths (e.g. up to 50mm for steel) at the same or reduced laser power. It also consumes less energy compared to atmospheric welding. The scalable pump station allows for quick evacuation of the welding chamber, resulting in little downtime between welds. In addition, the technology enables high feed speeds and short processing times due to its high energy density. Finally, the modular design and small size of the facility offer a high level of flexibility at a low price tag and fewer operating costs compared to available alternatives.

Selection of the welding process

The list of alternative processes for welding sensitive and highly stressed materials and components is short. Only two joining processes

  1. electron beam welding and
  2. laser welding in a vacuum

are available. The following comparison helps with the technical classification.

Electron beam weldingLaser Beam Welding in High-Vacuum

Brief description

  • Heated cathode in generator produces electron cloud
  • High voltage accelerates electrons towards the anode
  • Lenses focus electron beam
  • Guidance of the electron beam by magnetic fields
  • Welding feed through beam deflection
  • When the electrons collide with the component, the kinetic energy is converted into thermal energy.
  • X-rays are produced on impact
  • Photons excited by current in resonator emit energy in the form of light Wavelength of light depends on laser medium
  • Monochromatic, coherent laser beam leaves resonator through semi-transparent mirror
  • Wavelength depends on laser medium
  • Focusing of the laser beam via optical lenses
  • Laser beam guidance via fixed / movable mirrors, lenses, optical elements, light guides
  • Welding feed through component movement or beam deflection (e.g. scanner)
  • Thermal energy through energy absorption in the component
  • Degree of absorption varies with wavelength
    • Fast, inertia-free deflection of the electron beam
    • Multi-melting bath technology possible
    • High feed rates
    • Large welding depths achievable, controllable via variation of acceleration voltage (beam energy)
    • Low heat-affected zone and short cooling times
    • For almost all metals (incl. refractory), metal pairings
    • High energy efficiency of the generator
    • Fast, precise beam deflection via mirror system
    • Insensitive beam guidance (magnetic field, atmosphere)
    • Welding depth dependent on laser power
    • Very low heat-affected zone (pulsed laser)
    • For almost all metals (incl. refractory), metal pairings, plastics
    • Low energy consumption, wear-free energy source (laser)
    • No shielding against X-rays required
    • No stress on sensitive components (e.g. electronics)
    • Spatial separation of laser source and welding chamber possible
    • Laser technology is a technology of the future and focus of research
    • (Lead) shielding of the X-ray radiation required
    • Demagnetisation of the components required
    • Not suitable for sensitive (mechanical stress) or electronic (electromagnetic stress) components
    • Continuous wear of the cathode
    • Qualität des Vakuums beeinflusst Schweißbarkeit
    • High energy consumption
    • Direct connection of generator and welding chamber
    • Laser protection required (less complex than plumb)
    • Welding depth limited by laser power
    • Vapour deposition protection optical elements required

    High-vacuum laser welding

    Follow the creation of a 3-dimensional weld seam geometry in the video

    Areas of Application for KTW High-Vacuum Laser Welders

    High-vacuum laser welding is suitable for oxygen-affine or refractory metals as well as mixed material compounds. The latter includes steel alloys, stainless steel, aluminum, zirconium, titanium, beryllium, tungsten, molybdenum, tantalum, niobium, and mixed compounds.

    Applicable industries for the technology include aerospace and space/astronautics, the energy and renewables sector, as well as automobile, motor, and turbine construction. Furthermore, it is suited for electronics, sensorics, along with medical and defense technology. Due to the lack of mechanical stress, vacuum laser welding is especially suitable for sensors, sensitive electronics, and vacuumed hollow bodies like sensor housings.

    Our Service for All Your Laser Welder Needs

    If you would like to take advantage of KTW High-Vacuum Laser Beam Welders, we offer the following products and services:

    • Welding systems for laboratories and production
    • Help in process validation
    • Test welds
    • Small-batch contract welding
    • Process ramp up

    Latest News

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