The friction stir welding method ranks today among most promising and fast expanding welding techniques. Its principle was invented and patented at The Welding Institute UK in 1991. In FSW, a cylindrical-shouldered tool, with a profiled threaded/unthreaded probe (nib or pin) is rotated at a constant speed and fed at a constant traverse rate into the joint line between two pieces being welded. Frictional heat is generated between the wear resistant welding tool shoulder and nib, and the material of work pieces. This heat causes the stirred material to soften without reaching a melting point. After reaching a temperature needed, the tool traverse along the weld line making the weld. During the welding, mechanical forging and mixing of the two materials of the joint take place. The method features high productivity, quality and power efficiency.
Other advantages are as follows:
- Minimum twist due to internal stress
- Welding of “incompatible” and harder-to-weld materials
- Outstanding properties of the weld nearing those of base material
- No weld porosity
- High purity
- Independence of welding position (no macro-scopic melting)
- No added material
- No protective atmosphere required
- Minimum requirements for surface tratment before welding (no grinding, pickling, etc)
- High tool durability (typically a joint long 1 km)
- Possibility of material repairing and recovering
- Friction welding of aluminum, copper and magnesium alloys, mild steels and nickel alloys
- Friction welding technology transfer
- Friction condition optimization
- Manufacture of FSW tools
- Consultancy and test specimen manufacture
- Small batch production of pieces to weld (plate heat exchanger, light alloy reinforced panels, special profiles of Al and Cu alloys, etc)
- Welding NC machine based on FSK 80/A2 platform
- LOWSTIR® passive monitoring system
- Vacuum fixture using a Horst Witte Geraetebau system
- FSW tools of home and foreign provenience
- Aeronautical and astronautical industries (manufacture of airframes, fuel tanks, etc)
- Railway industry (manufacture of wagon body made of extruded profiles)
- Car industry (manufacture of tailored blanks, wheel disks, engine supports, centre tunnels, LPG tanks, etc)
- Ship industry ( side ship mantels, heliports, mining towers)
- Civil industry (light alloy bridges, building front panels, pipelines, chemical industry reactors, vaporizers for airconditiong units)
- Electrical industry (electric motor cases, electronic protective envelopes, connectors, terminal boards)
