The main advantages of friction stir welding are as follows:
The heating process has the characteristics of high energy density and fast heat input speed. The microstructure change of the heat-affected zone of the welded joint is small, so the welding deformation is small, and the residual stress after welding is small.
The weld is extruded in a plastic state and belongs to the solid phase connection, so the joint will not produce some fusion welding defects and catalytic phenomena related to metallurgical solidification, such as cracks, inclusions, pores, and burning of alloying elements. The weld performance is close to the base metal, and the mechanical properties are excellent.
It can perform butt joint and lap joint of flat plates, and can weld straight welds, fillet welds and circumferential welds; it can complete welding of long welds, large sections and different positions at one time, and the joint is high.
When producing FSW products, automated mechanical equipment for welding are used, which avoids the dependence on the technical proficiency of operators, with stable quality and high repeatability. The operation process is mechanized and automated, the equipment is simple, the energy consumption is low, the efficiency is high, and the requirements for the operating environment are low.
There is no need for filler materials (no need to add welding wire) and protective gas during welding, and the cost is low; there is no need to pre-treat the surface of the weldment before welding, and there is no need to apply protective measures during the welding process, and the edge of the thick weldment does not need to be grooved, simplifying the welding process. Welding aluminum alloy materials do not need to remove the oxide film, just remove the oil; it can weld materials sensitive to thermal cracks, suitable for welding dissimilar materials.
The stir welding process is safe, with no radiation, no pollution, no smoke, no radiation, low noise, etc.
