In manufacturing or construction industries, welding is a fundamental joining process. There are numerous welding techniques available, but stir welding stands out as one of the most innovative and efficient methods.
Once you read this article, you will know:
- What is stir welding,
- How does stir welding work,
- What are the key advantages of stir welding,
- What are the applications of stir welding?
What is stir welding?
Stir welding, also known as friction stir welding (FSW), is a solid-state welding process that was invented in the 1990s.
The key difference from the traditional welding techniques involving melting the materials is that stir welding creates a joint by mechanically stirring and plasticizing the materials without melting.
It is also worth mentioning that stir welding produces welds with exceptional mechanical properties, such as high tensile strength or fatigue resistance. It also generates fewer defects, such as porosity and inclusions, typical for fusion welding.
What is more, stir welding can effectively join dissimilar materials and consume less energy compared to traditional welding methods, so it is a more cost-effective option.
How does stir welding work?
The stir welding process is straightforward and consists of a few phases, such as:
- tool design: creating a specialized rotating tool with a geometry that enables generating frictional heat and mechanical pressure on the joint,
- tool rotation: plunging the tool into the joint between the two workpieces,
- stirring and plasticizing the material, creating a solid-state bond,
- joint formation: cooling and solidifying the material, forming a strong and defect-free weld.
As you can see, the process of stir welding is straightforward and does not entail any melting.
Nevertheless, the final shape and characteristics of this technique are due to the improvements that have taken place in recent years.
What are the key recent improvements in stir welding?
First of all, stir welding can now be used with a wide selection of materials, including steel, titanium, copper, and composites. Originally, it was developed for aluminum alloys.
What is more, recently, automation and robotics have been integrated into stir welding, which has enhanced its precision and repeatability in manufacturing processes.
Apart from automation, there have also been advanced tool designs and materials developed to increase the lifecycle of tools and their efficiency.
What are the applications of stir welding?
As you can see, stir welding is an innovative and effective welding technique that can improve manufacturing processes. Consequently, it can be applied across multiple industries, such as:
- Aerospace to join components like aircraft panels and rocket fuel tanks,
- Automotive manufacturing to produce vehicle components,
- Shipbuilding to ensure watertight and durable joints for hulls and structural components,
- Oil and gas to join pipes, tanks, and pressure vessels
- Railway manufacturing to create strong connections for railcar bodies,
- Space explorations to equip space missions with lightweight and robust welds.
All in all, stir welding is an effective technology that can be applied across various industries. As researchers and engineers continue to refine the process and improve it on a regular basis, it can become even more useful for manufacturing in the future.