The development of friction stir welding process
Welding technology is constantly developing, and friction stir welding has the advantages of good mechanical properties, low cost, high efficiency, green and pollution-free of the welded joint, Widely used by domestic and foreign manufacturers. In addition, academic discussions and research on friction stir welding are also very popular and have great research value. Introduced aluminum alloys and The application background and working principle of friction stir welding were explained, followed by an overview of the current research status of aluminum alloy friction stir welding technology and equipment. Finally, the development prospects of aluminum alloy friction stir welding were analyzed and discussed.
In recent years, welding technology has continuously improved and developed, and now various types of Welding techniques emerge endlessly, including various welding techniques such as friction stir welding, friction overlay welding, electron beam welding, laser welding, and composite weldingContinuing to emerge greatly enhances the welding of different materials under different working conditions Ability.
At present, people's enthusiasm for the research and development of friction stir welding is still very high. Statistical data shows that China has become the country with the highest investment in research and development of this technology in the world today, which indicates that friction stir welding is developing rapidly in China and is of great significance for its in-depth scientific research work.
Aluminum alloy is an alloy made by using aluminum elemental metal as the base material for overall alloy manufacturing, and adding a certain amount of other required metal or non-metallic elements to the base material during processing. Aluminum alloy materials have the characteristics of high strength density ratio, low density, good castability, good electronic conductivity, strong resistance to external environmental corrosion, and excellent welding performance. They are widely used in the aerospace field.
In addition, it also has very high commercial and strategic application value, with broad application prospects. In the aerospace manufacturing industry, the welding technology of aluminum alloys is also a widely used process. A large number of aluminum alloy products need to be welded before being put into use. Friction stir welding is widely used in aluminum alloy welding due to its excellent welding performance, high welding yield, and good welding effect.
In the process of material welding and manufacturing, the welding material of friction stir welding directly completes the entire welding without melting. In the welding process of friction stir welding, the friction and agitation of the required materials, the shoulder of the clamping device, and the specially designed finger rod cause the welded material to undergo plastic deformation and quickly enter a thermoplastic flow state. The welding process of friction stir welding is completed by mutual diffusion and dynamic recrystallization of the welding material. Friction stir welding is mainly composed of the rotation of the stirring head itself (clamp and special shaped finger), insertion of welding materials, thermoplastic properties of materials, and movement welding of the stirring head.
During welding, the workpiece is fixed on a rigid platform using a fixture, and then the friction stir welding head rotates at high speed along the surface of the workpiece relative to the direction of the workpiece's joint. The protruding end of the irregular rod extends into the metal material, friction and stirring are carried out on the welding area to soften the welded metal material and form a cavity. In addition, the shoulder of the gripper can prevent the softening and outflow of metal materials in a plastic state, eliminating the oxide layer on the surface of the welded part. Because the welding end of friction stir welding rotates at high speed, it first reaches a plastic deformation state before welding the metal material. The deformation process is constrained by the shoulder of the shaft. Afterwards, due to the movement of the specially designed finger rod, the material undergoes plastic deformation after high-speed stirring. Then slowly accumulate behind the stirring head to produce a weld seam, completing the process of stirring and friction.
Nowadays, the development of aluminum alloy friction stir welding technology is becoming increasingly perfect, and more and more new technologies and research are being applied to aluminum alloy welding. There is little room left for the exploration of the overall technology of friction stir welding, and there is relatively little specific research on the quality of welded joints, welded parts, and metal properties of welded parts. There is still room for further research. Aluminum alloy materials and friction stir welding are also widely used in various manufacturing industries, and aluminum alloy friction stir welding technology has great development prospects.
