Friction stir does it again one-and-a-half times faster
Friction stir does it again – one-and-a-half times faster
Keywords: Friction, Welding
At the latest meeting of "Friction stir welding of transport structures"at the end of September, sponsors were delighted to be told of dramatic results in the development of an advanced friction stir welding (FSW) tool.
Its use achieved an increase of 150 per cent in travel speed. Increasing welding speed substantially, while maintaining or improving the existing high weld quality was a prime objective of the project at its inception.
Welding trials have been conducted on the normally difficult-to-weld aerospace Al-Zn alloy 7075-T7351. So far a welding speed of over 400mm/min has been achieved when making butt joints in 6.35mm thick material. This represents an increase of at least 150 per cent on the speed achievable with current commercially available FSW tools. This tool also produces a higher weld nugget hardness leading to higher tensile strength values.
Even higher speeds are expected by changing the tool path about the axis of rotation. Trials will continue.
Two new companies recently joined the project. DanStir (Denmark) and Kawasaki Heavy Industries (Japan) are now part of the group of major international companies working on this research. Other sponsors are: Boeing Company (USA),British Aerospace (UK), British Aluminium (UK), CSM Materialteknik AB (Sweden),DERA (UK), ESAB Welding Equipment AB (Sweden), MTS Systems Corporation (USA) and Raufoss Materials Technology (Norway).
If you are interested in joining the project group and taking advantage of cutting edge developments in FSW, contact: Christopher Dawes, TWI Ltd, Granta Park, Great Abington, Cambridge CBI 6AL, UK. Tel: +44 (0)1223 891162; Fax: +44(0)1223 894367; e-mail: cjdawes@twi.co.uk
