Friction welding is a form of solid-state welding wherein heat is generated by mechanical friction between a moving component, and a stationary one. This high-powered heat joins the metals/materials together to form the weld.
Friction welding creates strong welds. Read on to learn about the process of friction welding, and find welding training near you today.
How does Friction Welding Work?
Friction welding is a more unique welding process. Unlike more typical forms of welding that use torches to liquify the metals to form a weld, friction welding creates heat through mechanical pressure. Since no melting occurs, friction welding is classified as a type of solid-state welding.
There is no pre-weld surface cleaning or preparation needed for friction welds, since the initial rubbing between the surfaces removes any impurities or oxide layers that could be present on either metals.
The general process for friction welding begins when one piece of metal is rotated relative to the other component that is pressed against it. This rotation is carried out under a mechanical compressive force with a defined level of pressure.
It is the friction that produces the intense heat between the two surfaces, which causes a displacive interference within the metals, plasticizing them, and producing a molecular bond – welding the pieces together.
The bonds created with friction welding tend to be strong due to their uniformity throughout both sides of the joints. Friction time, friction pressure, forging pressure, and rotational speed are considered the most important factors in the friction welding process.
What are the Types of Friction Welds?
There are a few different types of friction welding processes. The different methods refer to the type of motion that is used to create the weld.
- Linear Friction Welding - One piece is held stationary while the other is moved back and forth in a linear motion to create the weld.
- Rotary Friction Welding - One piece is held stationary while the other is rotated to create the weld.
- Friction Stir Welding - Both pieces are held stationary, while a rotating, non-consumable pin mechanism generates the needed heat. As the pin tool is moved along the seam between both pieces, it fuses the metals together.
Listed above are the main friction welding processes. There are other subsets of friction welding that are mainly used on thermoplastics. These are called Linear Vibration Welding and Orbital Friction Welding.
What Types of Metals can be Friction Welded?
Friction welding is mainly used on metals and thermoplastics. Following is a more specific list of the metals and materials that can be used in friction welding:
- Aluminum/Aluminum Alloys
- Titanium/Titanium Alloys
- Steel and Ferrous alloys
- Magnesium
- Copper/Copper alloys
- Hafnium and Zirconium
- Inconel and Superalloys
- Thermoplastics
- Dissimilar Metals
Friction welding is ideal for manufacturing industries for many reasons. One major reason being its ability to join dissimilar metals to form these strong welds – no matter what their fundamental properties are.
More Advantages of Friction Welding
Friction welding is becoming increasingly popular in a variety of industries. Some of the advantages of friction welding are:
- Versatility. As previously mentioned friction welding is used for dissimilar materials. Doing so creates strong welds that can be used in automotive, aircraft, naval, mining, defense and construction industries.
- Minimal HAZ. Since heat is generated from friction rather than a torch, the HAZ (heat affected zone) is very small on friction welds. Along with a small HAZ, friction welds result in very minimal porosity.
- Precise and Strong. Friction welds are strong and reliable. Since they are performed mechanically, their product is easy to replicate and precise in nature.
- No Prep Needed. There is virtually no pre-weld cleaning necessary. This is due to the fact that the rubbing taking place during the process automatically removes any oxide layers or possible impurities that would ordinarily interfere with welding.
- Reduction of Waste. Since it can craft materials that are nearly identical in shape without excessive machining, friction welding significantly reduces the amount of waste when compared to other processes.
Who Operates Friction Welding Machines?
A skilled welder must operate a friction welding machine. While it’s true that torches aren’t used in friction welding, the fact remains that skilled welders will be needed to operate the machines properly.
Since friction welding produces a degree of distortion in the joint, if it is not performed properly, it can result in a weak and fragile product. A skilled welder is needed to handle the machine and control the overall process of a friction weld. Although the weld itself is carried out robotically, the welder who operates the machine is needed to be highly skilled and knowledgeable in process.
You Can Learn Friction Welding!
Many see friction welds as the future of welding technology; their strength and versatility makes them viable processes that can be used in many industries. If you are interested in friction welding, but unsure where to begin learning, take the first step and find a welding school near you today! Some schools can have you career-ready in as few as 10 months.
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