Laser Welding

Aluminium

cross section of weld between two sheets of differing thickness

cross section of laser butt weld

The advent of higher laser powers, improved beam focusing systems and better beam quality has led to power densities sufficient to overcome the high surface reflectivity of aluminium. Some alloys are prone to cracking, but optimisation of the welding conditions and use of filler wire can eliminate this problem. Wire feed is also used for improving weld metal properties and tolerance to joint fit-up.

  • 5000 series alloys - good weldability with or without filler wire.
  • 6000 series alloys - good weldability with or without filler wire.
  • 2000 series alloys - parameter development is continuing.
  • 7000 series alloys - parameter development is continuing.

Porosity can also occur when laser welding aluminium, predominantly due to hydrogen entrapment in the molten pool. However, this can be minimised by correct cleaning and adequate shielding during welding.

Applications for Aluminium

Current and future industrial applications of aluminium laser welding includes fast ferries (catamarans), aluminium car components (e.g. Audi A2) and airframe structures.		 car body frame structure

Benefits of Laser Welding

  • High processing speed
  • Deep penetration welds
  • Low heat input, minimal distortion
  • Readily automated
 Laser welded T joint between two hollow extruded aluminium profiles

Typical Parameters

Thickness
mm		 CO 2 laser Solid state laser
Power
kW		 Speed
m/min		 Power
kW		 Speed
m/min
2 5 6 2 1
2     4 6
6 5 1 4 1.0

Contact:

Laser and Sheet Processes Group
TWI Ltd
Granta Park
Gt Abington
Cambridge, CB21 6AL (previously CB1 6AL), UK

email: lasers@twi.co.uk
Tel: +44 (0)1223 899000
Fax: 01223 890661
Copyright © 2004 TWI Ltd
Information and advice from TWI and its partners are provided in good faith and based, where appropriate, on the best engineering knowledge available at the time and incorporated into TWI's website in accordance with TWI's ISO 9001:2000 accredited status. No warranty expressed or implied is given regarding the results or effects of applying information or advice obtained from the website, nor is any responsibility accepted for any consequential loss or damage.