Friction Stir Welding (FSW), which was invented by Wayne Thomas at TWI in 1991, operates below the melting point of the work pieces to be joined. This leads to very high strength and minimal distortion. The process is consequently used in all areas of light-weight construction such as ship building, railway rolling stock, automotive and aerospace.
We offer turn-key solutions for close-loop force controlled FSW machines in close co-operation with Stirtec. These can be used for FSW at up to 25 kN (2.5 t) and for high-speed machining at up to 15,000 rpm. The work pieces can be machined before and after welding in the same fixture using these hybrid machine tools. This achieves significant cost savings and very tight tolerances.
Most metals can be friction stir welded, e.g.
Friction stir welding of aluminium or copper is now state of the art, but even friction stir welding of steels achieves very promising results.
The parts to be welded can be processed as follows:
Panels are assembled from aluminium extrusions in many industry sectors. Aluminium castings are increasingly used for making battery tubs for e-mobility.
Dissimilar materials can be friction stir welded, even if they have differnt melting points:
For FSW of dissimilar metals Special know-how is required regading tool design and set-up of the FSW machine.
Stephan Kallee (AluStir) reported on 19 April 2021 in this 1½h webinar for 55 students of University of Liège on Friction Stir Welding
© AluStir, Stephan Kallee, CC BY 3.0
Stephan Kallee (AluStir) reported on 19 April 2021 in this 1½h webinar for 55 students of University of Liège on Friction Stir Welding including the principle, applications, materials, FSW tools, CoreFlow™ at TWI, FSW machines (gantry, CNC machine or robot), FSSW, thin sheets and thick plates, accidents, FSP and conclusions. This webinar was organised, hosted and chaired by Dr Yves Marchal (Sonaca) on behalf of Prof Olivier Brüls (University of Liège) and covered the following topics:
Norway and Sweden were setting the trend
Boeing and Lockheed Martin on behalf of NASA
Heat Exchangers for Cooling Electronics in Trains
Automotive Body in White, Suspension Struts and Wheels
Steel: Only very few industrial applications
Copper: Sweden and Japan have been leading the field
The tool is the heart of friction stir welding
CNC- or Robo-Pin?
Cylinder or Cone?
Triflat or Triflute?
• Downward pressure is too low
• Tool position is too high
• Tool rotates in the wrong direction
• Gap between the work pieces
• Draft (taper on castings)
See www.aicamstir.com for more details.
Panel Welding machine - Prefabrication of FSW panels made from extrusions
Position or Force Control - Proprietary control algorithms are often used
Gantry Machines at TWI - Versatile machines for research & development
FSW Machines: Gantry at Eclipse Aviation - Commercial production of business jets
FSW machines (gantry, CNC machine or robot)
The visual appearance and hooking are challenging
Consoles for FSSW and Refill FSSW
FSSW in production of Mazda RX-8 since 2003
Non-disclosed prototype by Friction Stir Link in USA
Aluminium roof panels for high speed trains
Used in Japan, UK, USA etc
For joining billets, FSSW machines are made by two UK based companies
Solid phase pocess
Can operate in all positions
Simple machine tools
FSW of 1.2 mm thick aluminium sheets
FSW of 75 mm thick armored aluminium plates
Thick plate: 50 mm, 75 mm and up to 150 mm thick AA6082-T6
Ballistic impact test
Virgin Pendolino derailed on 23 Feb 2007 in Cumbria
FSW Balconies melted in Fire onboard ‘Star Princess’
FSP: Better microstructure than parent material
Friction stir processsing of aluminium casting
Patent Application by The Boeing Company
Products and services