TWI has developed a technique that enables ultra-thin aluminium alloy sheet to be joined by a process that uses neither glue nor welding filler wire. With this new technique, called micro-friction stir welding (μFSW), TWI has achieved perfect and permanent lap-welded and spot-welded joints to less than 0.3mm material thickness and butt welds to little more than 0.5mm thickness successfully in aluminium. Welding speeds have been in the range of 100mm/min to 500mm/min.

Potential applications for the μFSW process include the sealing of packages within the electronics and photonics industries and the welding of aluminium foil for use in the aerospace industry. Applications exist in other industries, including medical devices, consumer goods and food packaging.

TWI will continue to research with a view to creating the smallest possible joints.
These welds, some of the smallest of their kind in the world, were achieved using equipment that was specially designed and adapted by TWI’s engineers. www.twi.co.uk