Friction welding: principle, application, diagram and technology

Friction welding It originated in 1956 in the Soviet Union. Since the 1960s, it has expanded to other countries and has subsequently gained widespread recognition. Friction welding is a type of pressure welding in which the metal is heated by friction between one of the parts of the product being joined.

The final connection occurs at the end of the process, when a forging force is applied. This type of welding is used in aircraft and automotive manufacturing.

Friction welding of metal

Friction welding of metal Welding is a unique process for joining two metals, converting the mechanical energy of friction or rotation of one of the workpieces into thermal energy, generating heat precisely at the desired joint. During the heating process, the parts are pressed together with constant or increasing pressure. After the required heating, melting of the metal, and the joint formed by pressure, the welding process is completed by upsetting and abruptly stopping rotation.

At friction welding of metal In the connection area, as a result of pressure, the fatty films and oxides that interfere with a strong connection are destroyed.

Highly heated metal, reaching its melting point, under strong compression causes the metal atoms to grow into each other, resulting in the monolithic nature of the product. Thus, friction welding of metal includes the process:

• a secure fastening of parts in which one of them is movable and the other is not;
• heating metal mechanically to a plastic state, melting;
• the process of destruction of oxides and fatty films that interfere with the strength of the weld;
• hot metal edges establish metallic bonds at the atomic level;
• cessation of rotational movements, pressure, solidification mode of parts.

In the 1990s, a method was developed friction welding of metals with stirring. This method is used for butt welding of sheet non-ferrous metals: aluminum, titanium, their alloys, and steel. All alloys with a melting point of up to 1800°C are also welded.⁰With C, dissimilar metals can be joined. This is done using a rod-shaped tool with a tip that is inserted into the workpiece and extends along the entire required length. The tool rotates at very high speed, creating intense friction, heating the metal to a ductile state. The molten mass is mixed with the rotating tool and forced into the free space behind the tool. This process establishes metallic bonds and joins the metals. Once the work is completed, the tool is withdrawn from the workpiece. Key criteria friction welding of metals with stirring:

• welding speed;
• frequency of rotational movements;
• the force of pressing the tool, its movement, taking into account the metal being welded, its thickness;
• the dimensions of such a tool and the angle of its inclination.

Advantages of this type of welding:

• no need for high power;
• local heating zone, heating accuracy;
• welding speed;
• connection accuracy;
• no splashes.

Friction welding equipment

Friction welding equipment Designed for high-precision joining of two metals, the PST-80 is one of the most advanced machines. It is equipped with hydraulic clamps, a touchscreen for monitoring, controlling, and programming the welding cycle, a hydraulic power unit, and a lubrication station. It can weld heat-resistant and structural steel, and the weld cross-section has a fine-grain structure. Friction welding equipment The MAST-10 model is designed for butt welding of ferrous and non-ferrous metals and their alloys. The machine is semi-automated, with automated operations, except for loading parts. The PST-12, PST-20, and PST-50 models perform excellent welding, producing high-quality welds and operating quickly.