[Technical Column] About FSW part.2

Hello everyone,
Following up on our previous post, today we’ll continue exploring Friction Stir Welding (FSW).
When it comes to joining metals, most people think of traditional welding. However, a unique technique called Friction Stir Welding (FSW) has been gaining attention in recent years. Unlike conventional welding, FSW joins metals without melting them. In this article, we’ll break down the principles and advantages of this innovative process.

・How Friction Stir Welding Works
FSW is performed through the following steps:
1. Tool Insertion
A rotating tool—consisting of a probe and a shoulder—is pressed against the joint between two metal plates.
2. Softening by Frictional Heat
The rotation and pressure of the tool generate frictional heat, which softens the metal without melting it.
3. Stirring and Plastic Flow
The softened metal is stirred around the tool and mixed together, forming a solid bond.
4. Tool Movement and Cooling
As the tool moves along the joint, a continuous weld is formed. Once cooled, a strong and seamless joint remains.

Benefits of FSW
• No melting means fewer cracks or porosity
• No need for filler materials or shielding gas, reducing environmental impact
• High joint strength with minimal distortion
• Suitable for difficult-to-weld materials like aluminum and magnesium alloys

In our next post, we’ll dive deeper into real-world applications and explore how FSW can enhance design and manufacturing.

(written by So Fukui)