Friction Stir Welding
Friction stir welding is a welding process invented by TWI in 1991.
The process involves a spinning tool, in contact with the material
to be welded, with sufficient down force to create frictional heat
in the material (about 80% of the material's melting point). This
causes the material to become soft, allowing the spinning tool to
create the weld.
Friction stir welding is now widely used in the aerospace,
automotive, rail and ship building industries.
LowStir Friction Stir Welder
Unlike other friction stir welders, the LowStir friction stir
welding system includes a unit that attaches to most standard
milling machines via an ISO taper, making it an affordable option to
smaller enterprises. It is supplied with software to calibrate the
system, monitor the welding process and log welding parameters for
later analysis. The LowStir system, developed following a European
funded research project involving TWI, Fatronik, Applied
Measurements Ltd, Sigmapi Systems Ltd and Suffolk Precision Ltd, is
now manufactured and marketed by the LowStir Consortium (the latter
four companies listed - see Who We Are).
How friction stir welding works
Mk.1 unit in action
LowStir Mk.1 Unit
The original LowStir unit was a great success, combining high levels
of cost and energy efficiency with strong, reliable welds. Like all
friction stir welding, the LowStir provided a quicker, easier, and
more efficient process than traditional arc welding. Unlike other
friction stir welders, LowStir converted existing equipment, for the
first time allowing small and mid-sized businesses to experience these
benefits at a fraction of the cost of other friction stir welders.
Unlike the wireless LowStir Mk.2, the
LowStir Mk.1 unit was physically cabled to the monitoring computer,
requiring two bulky communications modules, as well as a substantial
supporting structure to keep the cable out of the area of operation.
Since this was proving slightly impractical in certain situations,
work began on the current version of the LowStir system - a completely
wireless system with the same efficiency and low cost as the Mk.1
For more details of the
current LowStir system, please see the Product