Laser in Vacuum Welding | Deeper, Cleaner Laser Welds

Weld

S355 stainless steel weld, >20mm depth, 6kW laser

Weld

S355 stainless steel weld, >20mm depth, 6kW laser

Vacuum Chamber

Laser welding in vacuum development system

Vacuum Chamber

Laser welding in vacuum development system

Discover the factory of the future

Laser in Vacuum (LiV) welding is a relatively new technique that achieves two to three times the depth of weld compared with conventional laser welding using shielding gas.

Welding in a vacuum eliminates the hot metal vapour plume that forms above the keyhole at atmospheric pressure, so the beam couples in more efficiently and spatter is minimised, allowing for double to triple the penetration depth.

What is Laser Welding in Vacuum?

The vacuum environment also lowers the temperature at which the metal boils, allowing a greater share of the beam’s energy to vaporise material rather than scatter it, while more effective degassing and the absence of air give a drastically reduced porosity and an oxidation-free weld bead.

Over double the welding depth achieved in air
Parallel-sided seams with reduced nailhead
Increased process stability; significantly reduced plasma plume
Reduced workpiece contamination from spattering and vaporisation
Quick set-up, with no filament change: a window swap takes seconds against minutes for a filament exchange

Laser in vacuum compared with standard laser

Laser in Vacuum

Top quality achievable
Gas-sensitive materials very weldable
High penetration welding achievable with relatively low power lasers
Low general risk of porosity
Very low risk of adhering spatter
Chambers and local vacuum seals restrict part geometry
Pricier than a standard laser

Standard Laser

Quality generally lower
Gas-sensitive materials tricky to weld
High penetration welding unachievable without great cost
High general risk of porosity
High risk of adhering spatter
Very flexible to workpiece geometry, with robot arms and gantry systems
Often more cost-effective

Against electron beam welding, laser in vacuum is more affected by reflective materials, and works to a largely fixed focal length where an electron beam can vary its focus dynamically. Set-up is simpler though: there is no filament to change, only a window to replace, and no x-ray shielding is required.

What are the Benefits of Laser Welding in Vacuum?

Conventional laser welding at atmospheric pressure leads to a build-up of hot metal vapour above the keyhole. This vapour plume scatters and refocuses the laser beam and drags chunks of molten metal from the melt pool, forming spatters.

Laser welding in a vacuum eliminates the hot vapour plume, as it can expand away from the keyhole vicinity much more quickly. This leads to a higher laser coupling-in efficiency and minimises spatter.

The vacuum environment also reduces the temperature at which the metal boils, allowing for double to triple the penetration depth, and allows for more effective degassing without any air present to oxidise the workpiece – resulting in drastically reduced porosity and a completely oxidation-free weld bead.

Laser welding in a vacuum can also prove more flexible than electron beam welding in some applications, due to the absence of x-rays and the avoidance of magnetism issues.

Gallery

Industries and Applications

Laser in vacuum welding is well suited to applications needing high penetration, pore-free welds, and is often more flexible than electron beam welding thanks to the absence of x-rays and magnetism issues.