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Friction Stir Welding

Friction Stir Welding

Friction Stir Welding is available at some of our selected European sites.

A rotating tool is pressed into the metal and moved along the line of the joint.  No filler metals or shielding gases are used. FSW takes advantage of the metal’s characteristic of withstanding major plastic deformation at high temperatures, though not above the melting point. Clean metal surfaces on the profiles that are to be joined are pressed together under high pressure. At the same time, mechanical action using a rotating tool creates friction heat. The pressure and the heat combined result in a new, homogenous structure.

Compare the process with fuse welding. Friction Stir Welding gives:

  • Increased strength
  • Increased impermeability – entirely nonporous, sealed joints, with higher strength than fusion-welded joints
  • Joint that are, in principle, flush with the surface
  • Reduces thermal deformation – only minor thermal stresses in the material, and consequently flat surfaces
  • Greater repeatability – production has few and easily controlled variables, which also creates close tolerances.

FSW is an established technique.  Sapa’s series production started in 1996.