Friction stir welding (FSW)

Friction stir welding is the optimal joining process for non-ferrous metals with a low melting temperature and for mixed-metal combinations.

Friction stir welding (FSW): the process

Friction stir welding is a process in which a rotating pin is traversed along the contact surfaces between the workpieces. The frictional heat plasticizes the material, which is welded together.

The FSW process is particularly suitable for joining non-ferrous metals with a low melting temperature and for mixed-material joints. Even materials that are difficult to weld or dissimilar materials such as aluminium, magnesium, copper, titanium or steel can be friction stir welded.

FSW process overview: 01 Approach and plunge; 02 Dwell time for heating; 03 Welding process; 04 Retraction at end of seam

Widespread areas of FSW applications

The Friction stir processing is used in various industries. The spectrum extends from the automotive industry, including the e-mobility market, and aerospace through to the electronics industry.

Friction Stir Welding for General industry
- Economical welding of complex 3D seams, e.g. on cooling systems for power electronics or housings for cell phones
- Cast components with aluminum sheets or sections
- Welds with high conductivity for transformers and batteries
- Joining of various material combinations – typically aluminium and its alloys, copper and magnesium alloys
Automotive industry
- Economical welding of complex 3D seams, for example on parts of cooling systems, vehicle bodies and powertrains or e-mobility components
- Joining of typical 4000/5000/6000 aluminum alloys and also hard-to-weld material combinations, e.g. aluminum sheets, continuously cast sections and cast components
Find out more about automation in the automotive industry
Friction Stir Welding for Aerospace industry
- Welding of highly reliable, gas-tight seams, e.g. on aircraft fuselage parts and rocket components
- Low heat distortion and special surface characteristics as well as material properties (e.g. tensile strength) at a very high level due to the low joining temperature
- Typical materials: high-strength 2000 and 7000 series aluminum alloys
Rail vehicle construction
- Joining of side walls and roof assemblies for high-speed trains and of aluminum sheets or sections (double-walled panels)
- Highly economical joining thanks to FSW gantry systems and integration of additional machining processes such as milling and drilling
- Typical materials: 6000 series aluminum alloys

Friction stir welding offers a number of advantages over conventional arc welding processes.

FSW ensures top weld quality

No welding defects such as pores or cracks
Joining of a wide variety of materials possible
Comparatively low heat input
High seam strength with minimal welding distortion

FSW guarantees cost-effectiveness

Economical joining of complex 3D geometries
Material savings through component optimization
No consumables such as shielding gas or filler wire

FSW is labelled as "green technology"

Environmentally friendly thanks to low energy consumption
No fume extraction or anti-glare measures required

KUKA cell4_FSW

Modular friction stir welding robot cell: the modern solution with low investment costs

Perfect friction stir welding: from engineering to service

From feasibility and process investigations to trial welds, FSW tool selection and parameter optimization, including the conceptual design, manufacture and delivery of the system, KUKA offers the entire spectrum of services associated with friction stir welding.