Friction stir welding is the mixing head high-speed rotation and friction with the welder, resulting in heat formation of the thermoplastic layer, stirring head and workpiece relative movement, in front of the stirring head of the continuous formation of thermoplastic metal transfer to the back of the stirring head, filling the rear cavity, thus forming a connecting method.

The stirring head is composed of a special type finger rod, a clamping device and a cylindrical body. At the beginning of welding, the stirring head is rotated at high speed, and the special type refers to the weld seam of the welded sheet, and the metal friction in contact with the special finger rod is heated, forming a thin thermoplastic layer. When the special reference rod is drilled into the workpiece surface, some of the metal is extruded to the surface and the shaft shoulder is rubbed with the surface of the welder to generate heat. And because of the sealing effect of the back plate, the thermoplastic metal is formed continuously to form the weld seam. In the whole process, the cavities are produced in The weld zone metal undergoes the process of extrusion, friction heat, plastic deformation, transfer, diffusion and recrystallization.

Characteristics of friction stir welding

Stir-Friction welding In addition to the ordinary welding method can be difficult to weld the material, there are the following advantages

1. The welding temperature is low, even in the case of long weld.

2. solid-phase connection, does not produce similar to weld the street the casting organization flaw. The various mechanical properties, such as fatigue, bending, stretching and other indicators are good.

3. before and after welding, the working hours are less and the cost of production is greatly reduced. The stirring and friction in the welding process can effectively remove the surface oxide film and adhesion impurities, and reduce the cleaning steps.

4. The welding process does not need to add protective gas and solder.

5. to be able to conduct full position welding, good adaptability, high efficiency,

Simple operation, easy to automate.

6. No smoke, radiation, splash, noise and other harmful materials such as arc, is an environmentally friendly link method.