State-of-the-art joining process for a variety of applications

Friction Stir Welding

Approach
Dip
Welding
Remove

The FSW-technology

Friction Stir Welding (FSW) is a solid-state joining method, i.e. the welding process is performed below the materials melting temperature in the solid state.

Functional principle
A wear-resistant rotating tool is plunged into the joining surface of the join partners and is subsequently traversed along the weld line. During cooling, an appropriate weld seam is produced between the respective components.
Friction stir welding can be principally applied to all materials which can be plasticized. The joining process, however, is particularly suitable for welding aluminium in all alloy and manufacturing forms for thicknesses from 0.5mm up to over 50mm. Apart from that, the process enables the joining of different (dissimilar) materials. For friction stir welding of aluminium alloys, the globally valid standard DIN EN ISO 25239 – Part 1-5 can be applied.

FSW of steel

Basically, the technological advantages of friction stir welding can be expanded to materials with high melting points as well. One important aspect of FSW is its applicability for joining of higher-strength steels, since the use of conventional welding methods such as arc welding is limited. The Stirtec-solution is based on the application of FSW-tools that are characterized by a high process reliability at comparatively low tool costs.

Advantages of FSW

Low distortion and residual stresses
Improved microstructure and fatigue strength
fully automatable and monitorable
Very high degree of reproducibility
No filler material or welding consumable required
No smoke, welding spatter or other emissions
An environment-friendly fabrication process

Weldable materials

FSW of hybrids

Aluminium of different alloy groups
Aluminium of different manufacturing processes (e.g. cast and wrought alloys)
Aluminium/magnesium
Aluminium/copper
Aluminium/steel
Copper/steel

Typical FSW weld seam geometries

Butt joint
Overlap joint
L-joint
T-joint
Special geometries upon request

Friction Stir Spot Welding

The RFSSW technology

The Refill Friction Stir Spot Welding (RFSSW) is a special form of Friction Stir Spot Welding (FSSW), in this process, the end hole is closed with the material, which is displaced during penetration. The result is a clean, closed surface.

The RFSSW provides, inter alia, a good alternative to the attachment method, such as Clinching or riveting. In contrast to riveting, intermetallic corrosion can be ruled out in the case of joints of the same type.

This process also uses the proven Stirtec quality control tool to provide 100% traceability.

The FSSW technology

Friction Stir Spot Welding (FSSW) is a special variant of the classical “linear” FSW process. The FSSW-method is particularly attractive for joining tasks, at which sealing and adhesive media are applied to the surfaces between the components to be joined.

Benefits FSSW & RFSSW

high process stability
process tolerant with respect to deviations in shape in the joining zone
can also be used when using sealants or adhesives in the joint zone or for coated metal sheets
environmentally and workplace friendly joining process
low distortion due to low heat input
little influence on the back of the weld
easy to automate
RFSSW: flat surface

Friction Stir Processing

The FSP technology

The increasing demands on the quality and the properties of manufactured components demand new cost-effective solution methods in order to be able to meet these requirements on the material.

A new method is the microstructure preparation by using Friction Stir Processing, or FSP.

The FSP method can be used on the one hand to change the microstructure in layers close to the surface, but also to repair small pores, for example in die castings, to achieve a local improvement of the microstructure through FSP.