Breakthrough triggers new project on friction stir welding steels
Breakthrough triggers new project on friction stir welding steels
Keyword Welding
TWI has shown that ferrous metals can now be added to the growing list of materials which can be joined by friction stir welding.
Recent development work has produced metre-long welds in ferritic steel with encouraging mechanical properties. TWI is now launching a new group-sponsored project to provide the expertise necessary for industry to exploit this breakthrough.
Since its invention and patent-filing in December 1991, friction stir welding (FSW) has made an enormous impact on the welding of aluminium extrusions and plates. Five companies are already using the process in commercial production, and approximately 30 companies now hold licences. This success and innovation have been recognised recently through a Millennium Product Award by the British Design Council.
FSW uses a non-consumable rotating probe, moving along the joint line, to create a high quality butt or lap weld. Since it is a solid-state process, FSW can be used to make high-quality welds in a wide range of metals and alloys, including those which cannot be joined by conventional arc welding.
The proposed group-sponsored project will provide a comprehensive evaluation of the friction stir welding process for steels, investigating both technical and economic issues. Considerable effort is needed. The programme will optimise tool designs and process parameters, and establish the service performance of welds and tools. Results will give sponsors the knowledge to profit from the opportunities offered by friction stir welding.
Aerospace, automotive,shipbuilding and defence industries have each benefited from the development of FSW for aluminium alloys. A successful project is expected to produce similar innovations in the use of steels.
Further information contact: Philip Threadgill or Stuart MacLachlan at TWI, Abington Hall, Abington,Cambridge CB1 6AL, UK. Tel: +44 (0)1223 891162; Fax: +44 (0)1223 992588; e-mail: smaclachlan(a).twi.co.uk www: http://www.twi.co.uk
