Process description
Friction stir welding

This process applies to bead welding the thermal effect created by the friction of a tool consisting of a revolving metal rod (or tip) fitted with reliefs and driven in rotation at high speed. The heat generated locally brings the metal to a pasty state, allowing the tool to plunge into the material and then move along the joint where it progresses like the "keyhole" of a high-energy beam [1] to form, after cooling, the weld itself.

This is a progressive welding process, as opposed to conventional friction welding, which is known elsewhere [2] and essentially global, obtained by rotation of one part rubbing against the other.

It competes directly with all other continuous fusion welding processes (arc, high-energy...