Friction stir welded heat sinks stay sealed

Heat sinks for electric vehicles (PHEV)

We have been welding heat sinks for the power electronics of electric vehicles since 2009, both for hybrid vehicles (PHEV) and for battery-electric vehicles (BEV). Usually these heat sinks are cast components with cooling channels, which are closed by a sheet metal cover. Friction stir welding is particularly suitable for this application, because unlike conventional welding processes, the unavoidable pores in casting have no negative influence on the tightness of the welded joint. Thanks to its reproducibility, friction stir welding is also particularly suitable for mass production Our automated production cells demonstrate that we can perform friction stir welding, cleaning and pressure testing fully automatically. Up to 200,000 heat sinks per production cell per year.

Tailor Welded Blanks (TWB) for Audi and Mercedes

Our friction stir welded TWB for the transmission tunnel of the Audi R8 was the first structural application of friction stir welding in Europe, besides being the world’s first aluminium TWB. For the Mercedes SL we manufactured the first three-part friction stir welded TWB in a mass-produced vehicle. We also welded the aluminium tailored blank for the Lamborghini Gallardo. Now we would be ready for the next model - after all, these TWBs have been used in real large-scale series in the USA for a long time. 

What applies to all of them: 
Friction stir welding joins sheets of different thicknesses before forming. The sheet thicknesses vary depending on the crash stability requirements. This saves material and weight - which is crucial in lightweight construction. Friction stir welded seams are excellent for forming, the blanks can be processed directly without reworking the seams. Only one forming tool is required - an enormous cost saving factor. In addition, as our process is reproducible it is ideal for any series production - not only for tailored blanks. 

Main floor of the Mercedes SL

The 2011 model variant of the Mercedes SL was the first all-aluminium bodyshell in a large-scale Mercedes series. The use of aluminium saved 110 kg of weight compared to the previous model. Our main floors make an important contribution to this weight reduction. They are made of extremely thin-walled hollow profiles and have been friction stir welded at RIFTEC over the entire model life. Despite the very thin-walled construction, the main floors must absorb crash energy in the event of an impact. In addition, they should be corrosion-resistant and reproducibly tight. With a MIG-welded connection this could have been guaranteed only by an additional sealing tape. That is why friction stir welding was taken into consideration. The installation situation of the main floors is very limited, moreover RIFTEC delivered directly to the assembly line in Bremen. To meet all these requirements and to minimize the distortion of the components, friction stir welding was the joining process of choice.

Energy and environment

Invisible welding seam – not only in aluminium

Ecological fan

Ecological fans are decentralized ventilation units with heat exchangers, which are in full trend in the face of climate change. We have been welding the perforated sheet metal cylinders for these fans for many years. As our seams are burr-free without rework and can be used in the visible area, friction stir welding scores here with its high surface quality among other aspects.

Copper facade

The term "invisible welding seam" also applies to our copper projects. Time and again we weld roof or facade elements made of copper and copper alloys. Copper is a material ideal for outdoor use, as it can withstand large temperature fluctuations, is maintenance-free and can be processed excellently. Friction stir welding is very well suited as a joining process, because it brings significantly less heat into the material than other joining processes. Thus, the characteristic properties of the material are largely preserved. And our seams can usually be used without rework in the visible area. 

Food industry

Pore-free welding seams

Drying trays for lyophilization

Drying trays made of friction stir welded aluminium profiles convince with their absolutely defectfree seam surfaces and gap-free connections that meet the highest hygienic requirements of the food industry. We manufacture in different variants and sizes from several extruded profiles which sometimes are very thin-walled. Due to the low wall thickness the total weight of the trays can be minimized. At the same time we achieve a high thermal conductivity which is substantial for lyophilization. With friction stir welding we also guarantee a very good flatness of the trays. 
We provide our customers with drying trays as a complete assembly including material procurement, production, surface treatment, assembly, marking and necessary certificates. The use of RFID tags is also possible. Both the trays for fully automatic continuous systems and those for manual discontinuous systems are manufactured at RIFTEC. In terms of quantities, anything is possible from small quantities for laboratories and small plants to the equipment of complete production lines. 

Slide plates for slicing machines

Friction stir welding is also the most suitable joining process for slide plates for slicing machines, because our welds are absolutely pore-free even when they are ground and machined. We fulfill the high hygiene requirements of the food industry. 
The finger- and thumb protection is welded as a sheet-metal profile combination in this application. We produce the slicing machines in large quantities as a series production over many years now. 


Friction stir welding for highest demands

Panels for the cargo floor

We weld prototypes and test parts for the aerospace industry on a regular basis. But we also produced a series of friction stir welded components for many years: High-strength aluminium profiles that serve as panels for the cargo floor of the A400M. Due to the high strength of the base material which amounts to 700 MPa, the panels could not be extruded in the required width. We have created the appropriate sizes by combining several narrow profiles and sheet metal sections. These cargo floor panels used to be the only friction stir welded component inside the A400M at that time, and also the first friction stir welded series component ever at Airbus.

Mixed compounds for space flights

Aerospace is a particularly demanding industry. For the mixed connections made of aluminium and titanium for our customers we use a rather new variant of friction stir welding: Welding with upright shoulder, also called "stationary shoulder". A special tool is used, where the tool shoulder – unlike with regular friction stir welding - does not rotate. Advantage: especially for very demanding applications, the process heat can be applied in a targeted manner and with relatively low axial force.

Mechanical and plant engineering

Friction stir welding of „Made in Germany“ quality

High weld penetration

For thick-walled components in mechanical and plant engineering, usually a high weld penetration is required. Often in combination with high-strength alloys, which is a very big challenge for most welding processes. But not for RIFTEC, especially since our new gantry system can realize a weld penetration of up to 30 mm per side. With the overhead welding module, we weld simultaneously from above and below up to 60 mm depending on the alloy.

Hollow profile as a welded construction

Rerailing bridges are used to lift derailed trains back into the track. These components must withstand high mechanical forces, but at the same time must not be too heavy, as they are needed everywhere on the line and should therefore be easy to carry. We create a hollow profile from two high-strength aluminium profiles, which is then further processed by the customer. The wall thicknesses are 15 - 20 mm. Also friction stir welding scores in this product with its high reproducibility and low heat input, which causes only little distortion.

Medical technology

High-vacuum-tight joints

Aluminium-steel joints

For medical technology we are welding high-vacuum-tight joints between an aluminium sheet calotte and a stainless steel ring. This component is used as an input screen in X-ray image amplifiers and therefore is safety relevant. Our series production has been running for more than 15 years and extends over several designs.

Rail vehicles and transport industry

A flying start with ultra-thin-walled profiles

Railway vehicle manufacturing

Our projects include display holders and roof coverings for domestic trains and abroad. We combine two very demanding extruded profiles by friction stir welding. In this case the particular challenge is the high demand on contour accuracy, which is necessary on the one hand because of the special positioning, on the other hand due to the high surface requirements - the weld is in the visible area. Both points to friction stir welding as the most suitable joining process.

As one of the few service providers for friction stir welding in Germany, we are certified for rail vehicle construction according to DIN EN 15085-2 CL1. We acquired the highest level of certification and are allowed to weld safety-relevant components for our customers.

Commercial vehicle construction

Just like in the automotive sector, lightweight construction is also an important topic in commercial vehicle construction. The same applies for FSW: We weld extremely demanding and thin-walled extruded profiles for our customers. They are used as seperating walls, floors or side walls for fire trucks and other applications in the commercial vehicle sector. Weight-optimized and distortion-optimized because of the low heat input during the welding.


Conductor rails, also known as "third rails", are responsible for the power supply to subway trains.They accompany trains over long distances, must withstand high loads and be absolutely reliable. We join three individual extruded aluminium and steel profiles to these robust rails with an extremely long linear seam of 15 metres. In Germany, hardly anyone else can realize these lengths with a continuous weld seam.


Friction stir welding convinces here with the excellent quality of the joint. Due to the plastic deformation of the material, a nearly homogeneous weld zone is created that is free of pores and inclusions. This ensures high load-bearing capacity and very high electrical conductivity. In addition, the joint is significantly stronger than with conventional welding processes and has a high fatigue strength and corrosion resistance.

Research and Development

Shaping the future with RIFTEC


We take part in various relevant events with exciting presentations on a regular basis. Just last October, our Managing Director Dr. Axel Meyer gave a presentation at the „International Conference on Advanced Joining Processes“ in Portuguese Sintra on a process comparison between friction stir welding, laser welding, MIG and laser MIG hybrid welding. Guess which procedure did best... 

In 2022, we held a round robin on this very topic. It was about a neutral comparison of different joining processes, which also paid particular attention to the carbon footprint. Please find the results here.

Committee work

Dr. Axel Meyer, Managing Director at RIFTEC, is Deputy Chairman of the DVS Research Association "Welding and Related Processes". He also heads the FA 5 (= Technical Committee 5) dealing with special welding processes. 
We act as industry partner in various project-accompanying committees and our expertise is in regular demand at the RAISER Innovation Award.
Regionally, we have been involved in the „Wirtschaftliche Vereinigung Geesthacht (WVG)“ (an economic association) for several years. 
Of course, we are also involved in the promotion of young talent, we participate in the Future Day, supervise interns and train our own young talent.