What are the advantages of friction stir welding technology compared to traditional welding technology? People familiar with the industry know that modern welding technology has gradually begun to use stir friction welding technology, this is because of its technical advantages, economic advantages and environmental protection and other advantages, mainly in the following areas.
1, stir friction welding solid phase welding process, high mechanical properties of the weld
No porosity, no burning of alloying elements, no thermal cracking; joint strength exceeds that of most fusion welded joints, and the joint performance is consistent.
2, stir friction welding welding process is simple
Friction stir welding is similar to a fully mechanical process, no welding preparation is required and equipment maintenance is simple. It is fully automated and requires no welding shielding gas or wire filler; it requires little assembly or pre-weld cleaning and can be applied at any position.
3、Friction stir welding head has good physical properties
Such as conductivity, thermal conductivity and parent material consistent, the weld colour and parent material consistent.
4、Friction stir welding does not pollute the environment
No arc, fume and spatter hazards; no ultraviolet light and electromagnetic radiation hazards; low energy consumption; no noise, the process is almost completely in a quiet state.
5、Friction stir welding is highly efficient
It can weld a thickness of more than 75mm at a time, and the defect incidence is lower compared with the traditional fusion welding technology, which can greatly reduce the rework rate, and the defects can be eliminated by welding again. A 15% reduction in labour per tonne can be achieved in the welding of aluminium alloys. It has been reported that using this welding technology on Delta rocket tanks can save 60% of welding costs and reduce working time from 23 days to 6 days. The use of stir friction welding technology for large complex structural aluminium alloy components has reduced the cost of tooling construction from 61% to 19%.
6. Not easily deformed
The deformation of the weld material is only one twelfth of that of traditional fusion welding. According to the data, stir friction welding is used in the manufacture of central aluminium alloy components for GT racing, and the joint strength is 30% higher than that of fusion welding. When using stir friction welding technology to manufacture aircraft fuselages, it is able to reduce weight by 0.9 kg per metre of weld.
Numerous studies and practices have proven that the use of aluminium alloys in vehicles and aircraft is the most effective way to achieve light weight. The use of friction stir welding technology in the manufacture of high-speed trains has become a mainstream trend. As the strength of the friction stir welding joint is better than the traditional fusion welding joint, and the defect rate is low, and the cost can be saved, the application in aircraft manufacturing has become an inevitable trend.
Compared with the steel structure, the aluminium alloy structure of the ship has the characteristics of high speed, flexibility and energy saving, therefore, the use of aluminium alloy to replace the original steel as a basic shipbuilding material has become a new trend in the shipbuilding industry. According to the introduction, stir friction welding technology has become the dominant welding process for industrial aluminium, magnesium and copper materials.
Stir friction welding has fully replaced traditional arc fusion welding in the manufacture of large sealed structures. It can be seen that the use of stir friction welding technology to manufacture large ship aluminum alloy structural parts has become unstoppable.