Product category:
Arc welding equipment, manual and automatic
News Release from: TPS-Fronius | Subject: Arc, plasma arc and resistance welding
Edited by the Manufacturingtalk Editorial
Team on 06 October 2005
Using innovation to expand welding
limits
Developments at the Schweissen und Schneiden welding fair highlight joining steel and aluminium, resistance welding progress and plasma cutting process, recalls Heinz Hackl.
"The Schweissen and Schneiden (Welding and Cutting) trade fair is setting new standards in 2005 for joining and separating technologies in the metals sector" "If we had merely redefined established doctrines, that alone would have been remarkable"
This article was originally published on Manufacturingtalk on 14 Jul 2008 at 8.00am (UK)
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"But what is even more exciting is that professionals using these systems can now reach beyond previously impassable limits", claims Heinz Hackl on 12th September 2005 in Essen.
The senior manager at Fronius International with responsibility for research and development in the group singles out three application examples: metallurgical joining of two chemically and physically very different metals, aluminium and steel, resistance spot welding of metals that were previously considered unsuitable for the process but are being increasingly used due to their technical and economic benefits, and also a new plasma cutting technology that breaks radically with previous limitations in flexibility and mobility.
As a result, users can make use of spectacular design, production-based, application-related, economical and ecologically friendly resources.
Further reading
Arc welding systems innovations advance
Innovative manual and automatic arc welding systems to be shown at MACH 2008 include cold metal transfer, digital TIG, digital MIG/MAG and the welding of speciality steels.
Steam plasma-arc cuts faster, precisely
Steam plasma-arc cutting system establishes a kerf more quickly, allows very precise profiling and will cut through sheets up to 10mm thick, including steel, chromed steel and aluminium.
Intelligent welding and soldering are faster
As well as its growing use among automotive OEMs, cold metal transfer arc welding is just as suited to the small firm with one automated welding workstation as it is for batch production.
* Metallurgically joining aluminium and steel 'intrinsically - at EuroBlech 2004, a good ten months before Schweissen and Schneiden, Fronius introduced the new and revolutionary 'cold' welding process CMT (cold metal transfer).
The process and its result, i e, the application, enables a clear distinction to be made from conventional arc welding".
""The combination of controlled reversal of the wire movement and a digitally controlled arc is the major difference".
"In the meantime, it has also been demonstrated in the field by well-known manufacturing companies," explains Hackl, who goes on: "Wire retraction with virtually no current, at a frequency of up to 70Hz, significantly reduces the heat input into the workpiece".
"The controlled droplet detachment is spatter-free." In the first year of application we have succeeded in further developing the process of joining aluminium and steel.
This process opens up a whole new range of opportunities in design and manufacturing.
It paves the way for a whole raft of creative new applications and intelligent solutions.
The even seam of the CMT process is one of the prerequisites for joining aluminium with galvanized sheet steel.
The Austrian leader in welding technology calls this process 'arc joining'.
The reason: the aluminium side of the join is welded, whereas the steel side is brazed.
Extensive tests in the field came up with some very interesting results.
Steel-aluminium sheets were first joined using a weld-braze butt joint and then shaped.
The result: the weld satisfies both rigidity and corrosion resistance requirements.
* Never-ending advantages - until now, resistance welding in general, and resistance spot welding in particular, were not available from arc welding specialists in Austria.
Fronius has good reasons for shifting this limit.
The trend in conventional resistance spot welding seems to be on the decline.
Its main application is in body work (automobile industry).
Efforts are being made to reduce the body weight of modern vehicles - not just passenger cars - but commercial vehicles and railroad rolling stock as well.
This frees up space for extra technical features, more comfortable interiors, and saves fuel.
Aluminium and combinations of normal sheet steel and high-strength special steels are now the trend.
Unlike the joining of conventional sheet steel, resistance welding is rarely requested on technical and economic grounds.
The new 'DeltaSpot' process offers a lucrative alternative to other mechanical joining processes.
DeltaSpot represents a totally new type of robot welding gun.
The defining feature is the process tape that runs between electrode and the sheets being welded.
It prevents their direct contact, thereby creating the precondition for a new dimension in repeatability.
The application of energy can be further controlled by the electrical resistance of the process tape.
This helps apply extra heat to the join, particularly when spot welding highly conductive materials such as aluminium, and this in turn reduces the welding current required.
The process tape moves automatically to its next position after every weld, i e, DeltaSpot is constantly welding a fresh contact surface.
There are also other advantages: "The circulating process tapes protect the electrodes as well as the materials being welded, prevent spatter and eliminate the rework that would otherwise be necessary, thus setting new quality standards," adds Hackl.
As well as its own investigations, Fronius can point to the results of its collaboration with Audi for the VW group.
Audi endorses the interesting and low-cost alternative to punch-riveting and screw joints.
What makes DeltaSpot so flexible from a technical point of view is the large process window".
""We can precisely control the current and the time it takes to reach the weld point".
"Compared to conventional resistance spot welding, and depending on the application, we can utilise a significantly larger process window," explains Hackl.
As both the size of the joins and their positions can be controlled, the new system can even be used in special welding applications: Aluminium-steel and three-sheet joins.
With these properties one can foresee applications in the automobile industry and beyond, white goods for example.
* Plasma cutting with liquid instead of gas - the Austrian welding specialists are shifting other limits with the 'TransCut 300' plasma cutting system: cutting can now be added to welding.
This entry into metal cutting also means a change of direction in plasma cutting".
""Portable, generatorcompatible systems will have a significant impact on cutting processes in the field".
"In future, environmentally-friendly and healthier 'green' cutting will become the norm in all aspects of the metal-working industry," explains Hackl confidently.
The advantage of the new technology is based on the distinctive merits of liquids over compressed air or gases as a technical medium.
It requires very little space, so can easily be stored on site.
There is no longer any need for a connection for the cutting gas or compressed air.
As emissions are conspicuously low, the liquid medium helps facilitate an environmentally friendly and healthier 'green' cutting environment.
The all-important difference in TransCut 300 lies in the supply concept.
An integral tank contains the liquid cutting medium.
It holds 1.5 litres and can be easily topped up using cartridges.
This liquid, in a vaporised and ionised form, serves as the medium for the plasma.
Consumption is just a few grams per minute.
On a typical building site, one tank will last about one month.
Last but not least, the economic argument should convince many potential users: The higher cutting speed means higher productivity.
* About the author - Heinz Hackl is the senior manager at Fronius International with responsibility for research and development.
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