Friction Stir Welding （FSW）

Friction Stir Welding (FSW) was developed in 1990, based on the principle that two separate metals can be stirred/welded together in plastic form with frictional heat, without a need for added heat or added filler material, this technique is licensed in the UK. Some features of FSW are showed below

1.      Increased strength

2.      Increased leakproofness – entirely void-free, impermeable joints of a higher strength than fusion welded joints.

3.      Joints that are, in principle, flush with the surface.

4.      Reduced thermal deformation – only low thermal stress in the material, hence the flat surface

5.      Increased repeatability – production has few variables and these are easily controlled; the result is tight tolerance.

As one of the companies who developed this process, Sapa group has so far the most experience in its application. Sapa Profiles Shanghai had introduced this process from the very beginning. More than 50% of our products are today made out of FSW. With FSW, we can exceed the limitation of the extrusion process “limited sectional size” and make a section wider than 600mm, which made product based on aluminum profiles a solution for many customers, large size heat sinks, train and ship floor, etc.