The surfaces of two thermoplastic products to be butted contact each other and rotate, so that they generate friction and heat successively, and the joint surface is heated and melted, thus becoming a whole welding method under pressure.
Friction welding can be used not only to weld plastic products, but also to weld different surfaces that are difficult to be achieved by ordinary welding, such as steel-steel, steel-aluminum, copper-aluminum and so on. Friction welding is very fast, each workpiece only takes a few seconds, while ordinary welding takes several times. Moreover, friction welding will not produce occupational hazards harmful to human body such as welding dust, manganese and nickel. The strength of friction welding is also great, sometimes even greater than the strength of the material itself, that is, when the external force is hard to pull, it is the material without welding that breaks first, not the welding point.
The origin of friction welding can be traced back to A.D. 189 1 year, when the United States approved the first patent of this welding method. This patent uses friction heat to connect steel cables. Subsequently, Germany, Britain, the former Soviet Union, Japan and other countries have successively developed the production and application of friction welding. As early as 1957, aluminum-copper friction welding was successfully carried out in China through the closed pressure principle experiment. After more than 50 years of development, friction welding has been widely used in high-tech fields such as aviation, aerospace, nuclear energy, marine development and other industrial sectors such as electric power, machinery manufacturing, oil drilling and automobile manufacturing because of its high quality, precision, high efficiency and energy saving.