In our previous article, we’ve enlighten on different types of welding processes and explained welding to be a process by which two part are joined together. Today you’ll have understanding on what is friction welding, its application, advantages and disadvantages.
What is friction welding?
Friction welding is a solid state welding techniques that generates heat through mechanical friction between the work pieces in relative’s motion with one another with the addition of literal forces which helps in joining the part.
It is totally different from fusion welding but more of forge welding which is because no melting occurs. The joint is obtained because of the thermo mechanical treatment at the contact surface.
In this type of welding the work piece are joined either relative to each other or by rotating in order to produce friction and displaces the material plastically on the surface. A very high pressure is needed here to accomplish the weld.
As earlier mentioned, it generates heat at the melting part of the work piece in order to obtain when external pressure is applied to it. The friction takes place between the parts until it turns plastic, normally at 900-1300 centigrade of steel. At this point, a uniformly increasing pressure force is applied to the work piece and a permanent joint is obtained.
Applications of friction welding:
Friction welding is used in welding tube and shafts, also used in aerospace, marine, oil and automobile industries. It is also applicable in component where friction welding is needed, items like, gears, axle tube, driveline, valves etc. It is also used to join hydraulic piston rod, truck rollers bushes etc. it is used to weld drill bits, connecting rod, gear levers etc. Finally, it is widely used in electrical industries for welding copper and aluminum equipment.
What are the advantages and disadvantages of friction welding?
Now you can see that this type of welding is applicable to different field and can be to weld different items. This is because it helps in reducing grain growth in engineering materials such as high-strength heat-treatment steel. And because no melting is involved. Dissimilar materials can be joined In this type of welding. That is why it is applicable in aerospace, where lightweight material like aluminum and high strength are to be joined.
Another advantage is that, the weld surface is cleaned due to the motion between the materials that are joined and full strength is obtained in joint with no additional weight to the work piece.
Friction welding is also used with thermoplastics materials. It uses very low heat and pressure on the materials. This has shown that, this type of welding can be used to join metals to plastics with the metal interface being machined.
Some other advantages of are:
- It is environmental friendly process. That is, the welding operation can be performed anywhere as it generate no smoke, flame, light etc.
- No filler material is required.
- The welding process is fast.
- It is easily automated.
One of the greatest disadvantages of friction welding is that, it has limitations to work piece dimensions. In sense that round bars with similar cross section is restricted, joint designs are limited and the work pieces need to be fixed.
- Friction welding equipment is of high cost.
- Materials that cannot be forged won’t weld.