The high-speed rotating mixing head penetrates into the workpiece and moves in the welding direction. The contact part between the mixing head and the workpiece generates heat through friction, which softens the plasticity of the surrounding metal.

The softened layer of metal fills the cavity formed behind the stirring needle under the action of the stirring head, and the material is firmly connected under the action of stirring and extrusion.

At present, it is mainly used in the connection of different or dissimilar materials such as aluminum, copper and magnesium.