FRICTION WELDING

Definition: It is a solid-state metal joining process in which metal is melt by the  heat  produced by rubbing the surfaces with mechanical friction

Working: In this one job is rotated at a very high speed with chuck while the second part is held stationary in another chuck. The second part move towards the rotating part.Due to high pressure and mechanical friction between the surfaces, these parts get heat up to their melting point. After that, the rotation of the chuck is stopped. To complete the process, high pressure is applied (upsetting) which will produce the solid-state welding. The rotation of the chuck to rotate the job is directly proportional to the thermal conductivity of the metal. Axial pressure can vary from 42MPa to 145MPa depends upon the material, thermal conductivity of the material

In this process welding time very short (few seconds) and gives a thin heat-affected zone. Because of that, we can use this on different material
NOTE: Rotary motion stopped suddenly so that axial pressure (upsetting) can be done correctly

Advantage of friction welding:

• In friction welding, the heat zone is very thin so you can easily be joined dissimilar metals. Example copper to steel, copper to aluminum
• Clean Process(less gas , fumes are produced in this welding process)
• High-quality weld is produced by this method
• Annealing is not necessary to the weld zone
• This process welds the whole surface unlike arc welding which welds only on the periphery
• Does not require any consumable tool
• Low initial capital investment
• Does not require shielding, inert gas, flux, filler material
• fine grains and equi-axial structure is produced at heat affected areas

Disadvantages of friction welding:

• Suitable for small jobs
• Mostly suitable for circular parts like pipes, circular rod

Applications of friction welding:

• It is used in rocket building, farm machinery ,powerplant,machine tool buildings, etc
• ISRO,NASA also use this welding process 

Other Blog

• Explosive Welding