friction spot welding - the new process

Harms + Wende tradition und innovation: Competence, innovation and uncompromising solution-orientation are the main things that characterize our company.

 

 

It is our demand to develop and realize resistance and friction welding systems on a high level. That is a demand which we live with our partners and customers for more than 60 years. We always have an eye on the quality of the products which are welded with our systems: that is our drive and motivation for the realization of new ideas. And that is the reason why we feel bonded with our tradition of innovation as well.

Our aim: the controlled welding process!

 

The future begins each day!

Punctiform overlap joints – a joining principle which has proved its worth millions of times is being reinterpreted. Two prerequisites lead to success. Firstly, uncompromising joint quality and process reliability thanks to friction welding and secondly, the economic and simple joining principle offered by spot welding. Two tried-and-tested processes are leading to a new, successful combination – FrictionSpotWelding!
An unbeatable combination for welding wrought alloys. Aluminum, magnesium and mixed materials can now be welded reliably and simply using FrictionSpotWelding.

 

 

The new process - stunningly simple

Rotating stroke tools heat up the joining zone. The material, which is rapidly heated, is now in a plastifiable condition and can be wrought. The tools penetrate and mix the material. After cooling, an integral joint is formed. In friction welding, the typical joining temperature lies below the melting point. Low thermal entrainment and mechanical reforming lead to a very fine-grained structure in the joining zone.


The basic material’s properties are retained – a firm joint of extraordinary quality is created.

 

How it works: The process sequence

The rotating pin and sleeve tools are positioned on the joining area. The heat which occurs transforms the solid material to a plastifiable, non-molten condition. The rotating sleeve penetrates into the "doughy" material. At the same time, the "inner" pin is lifted from the tool; this creates a cavity. This cavity takes up the displaced volume.

The plunger lies flat on the surface of the material; material is prevented from escaping uncontrolled. The sleeve penetrates through the upper sheet and into the lower layer.

On moving backwards, the sleeve is drawn out of the joining zone. At the same time, the pin presses the plastic material back into the joining area:
the cavity is filled again. The material is secured by briefly repositioning the tools. An integral, punctiform and plane joint are obtained. 

 

 

 

No mercy - testing to the limit

Fatigue strength, pelling, tensile shear and cross tension – these are the tests which have to be completed successfully...
In character, FrictionSpotWelding is spot welding. The advantage: existing test concepts can be directly applied.

 

New perspectives in lightweight design

FrictionSpotWelding guarantees "genuine" welded joints without disturbing contours. It is characterized by maximum process reliability and astonishing flexibility. This opens up new possibilities for processing lightweight materials.

 

More materials - more application options

Aluminum is the material with which the new FSW process really demonstrates its strengths. No matter whether wrought or cast aluminum materials are involved, from 1000 to 7000 alloys, regardless of whether these are of the same type or mixed combinations, FrictionSpotWelding offers the solution.

 

Punctiform joints on alloys

Punctiform overlap joining has long been regarded as a robust, well-known and simple joining method. Its essential advantages include familiar test methods, simple implementation and usually uncomplicated integration into existing process sequences; ideal prerequisites for fast and successful use in aluminum engineering.

 

Solid joint - a question of diameter

In FrictionSpotWelding, the spot diameter is determined by the diameter of the tool, with minimal scatter. FSW provides reproducible strengths without significant scatter and is therefore the ideal process for precisely engineering components.

 

Mixed combinations

Magnesium, nonferrous metals and lightweight design alloys are suitable for friction welding and can therefore also be used in the FSW process.

 


 

No access - no joint

Clear condition: the tool must be properly frictionally connected with the sheet – and welding can begin. Uncomplicated work with a simple tong is entirely sufficient for welding sheet structures. This ensures the necessary support from below.

 

As strong as the original material

FrictionSpotWelding means joining beneath the solidus curve, no recrystallization and low thermal entrainment. Ideal prerequisites for retaining the original material characteristics. Respectable result: maximum strength!

The process has no liquid phase and therefore does not lead to spatter. A matter of principle! The convincing result is an appealing appearance, clean components and the pleasant fact that laborious cleaning of parts is omitted.

Time is money, and a short cycle time is money saved. Just 1 second is needed to weld a 1 mm thick sheet.

 

Brilliant head - RPS100 SK

The RPS100 SK welding head is designed as a modular component which combines all of the functions required for the process sequence. The head provides the power stroke for the pin and sleeve, is equipped with a powerful drive and offers compact dimensions. The RPS100 SK, the power pack for efficient welding. Thanks to defined assembly interfaces, the welding head can be easily integrated into a master system concept.

 

A perfect result looks fine!

Two rings that weld together: optimal prerequisite for joints that can take the strain! Two concentric rings – the gleaming impression left by the tools on the upper side of the sheet; slight traces of thermal influence on the rear. Perfection which looks just fine!

 

Interaction of forces

Absolute synchronization is a must! The precise volume of the displaced material has to be filled in again. Without pores, without inclusions. This is the high-performance control system’s job. It synchronizes the drives and ensures perfect welding results.

 

Quality assurance:

Precise parameter control ensures
flawless welding process monitoring.

 

A strong team

The modular design of the components enables the welding tool to be flexibly integrated into the system concept. As a function carrier, the friction welding head
can therefore be individually installed in an existing system. As a full solution, the C tong – e.g. for connection to a robot – is suitable as a "standard solution" for conventional sheet structures.

 

Real bite - RPS100 ZA C tong


A complete system in the form of a C tong, which is characterized by good accessibility, a slim design and high flexibility. This ensures that the spot can be positioned even in areas which are difficult to access. Thanks to the modular design, a tong arm can be easily modified for diverse requirements.

 

Friction welding: the special process

Friction welding has the stubborn reputation of offering extraordinarily high process reliability. Justifiably so!
Welding below the melting temperature always guarantees good correlation between the parameters and the welding result. Hardly any other process offers better prerequisites for outstanding results. You can benefit from this: with the new FSW process, the advantages of friction welding can now be transferred to punctiform overlap joints. Simply and reliably!

 

 

Field of application of Harms+Wende friction spot welding systems

 

Friction spot welding is suitable for applications in automotive engineering, in aviation and space travel, for rail vehicles, in building construction, for conveyor systems, etc. It is outstandingly suitable for the omnipresent material aluminum, even if this often cannot be seen.