Production Constellium for Complex Assemblies Made of Aluminum
Lionel Chapis, Managing Director Automotive Structures, demonstrates the technology and strategy behind the expansion of the Dahenfeld plant to produce large-format structural components from aluminum for the first time.
Mr. Chapis, what are Constellium's concrete plans for the new production facilities in Dahenfeld?
For the first time, we supply not only individual body structure parts, but complete assemblies as well. We have already intensively processed the structural parts of the bodywork — machining, riveting, welding, surface finishing. The new thing is that we are now joining sheets, extruded profiles, and cast parts made of aluminum - and sometimes even steel sheets — to create more complex assemblies. In our highly automated production cells, we use joining techniques such as flow screws, self-pierce riveting, gluing, and spot welding. A special structural component for a premium sports car is produced on each of the two new assembly cells. However, the tools and robots are absolutely compatible — therefore any structural component could be manufactured in the other assembly cell without any problems as well. We are currently building a third plant, the fourth will go into operation in 2019.
How many individual parts are joined and how many machining steps are involved?
The largest structural component we currently produce, i.e. the side skirts, consists of 20 individual parts. These parts are joined together with about 20 flow screws, 80 rivets, as well as adhesive beads of up to four meters in length. Apart from the two highly automated assembly cells, we have expanded our fleet of semi-automatic welding cells. On these smaller plants we currently produce about 50 different assemblies in series.
Does this process chain in Dahenfeld serve as a model for other plants?
Absolutely. At this location, this is the first time we have manufactured structural components at this level of processing depth. Based on this experience, we also want to establish highly automated body-in-white production at other plants. This will take place over the next few years at one location each in North America and China, depending on local customers and potential orders.
Why has Dahenfeld been chosen as a pilot plant?
Dahenfeld already played a leading role within our company when it came to machining individual parts from extruded profiles and sheet metal. The workers and engineers at this location have a lot of experience in parts machining, are very close to many potential customers, and understand their quality demands.
Is this step from part production and machining to the supply of complete assemblies just a stopover? What’s next?
The next step will not necessarily be a higher degree of automated value creation. First of all, we want to transfer the know-how from previous projects with 50,000 to 60,000 units per year to mass production. This will not take place in Dahenfeld, but at larger locations close to volume manufacturers.
What volumes can be handled in Dahenfeld?
In Dahenfeld, we estimate the maximum volume to be around 60,000 units per year. Since some assemblies — such as sills — are found twice in each vehicle, this amounts to more than 100,000 structural components per order every year.
Do you want to manufacture and process even more extensive structural components?
The step from smaller to even larger assemblies is more than just a matter of size. The production and processing of larger assemblies require completely different capabilities. In addition, OEMs and car body specialists often define complex car body construction as their core competence. In this competitive and technological environment, Constellium does not regard market entry as a realistic option.
But you consider the production of further assemblies?
Absolutely. We have already received several series orders for battery housings. The corresponding electric vehicles from European, North American, and Chinese customers will soon be available on the market. We are currently well positioned with the production of battery housings, structural components from Dahenfeld, and crash structures for bumpers. In all of these products, lightweight construction, crash requirements, and production technology play a major role — this is well in line with Constellium's spectrum of expertise and the product properties of aluminum as a material.
Can Constellium cover the entire product and process portfolio with its own competencies or do you require external know-how?
By and large, we already have the expertise in-house. For instance, Constellium is operating a technology center near London in cooperation with Brunel University. There we jointly develop materials and joining processes, operate a small sample production facility and train our specialist personnel. In addition, there is our advance and materials development in Grenoble and a technology center in Gottmadingen on Lake Constance. In addition, we also collaborate with external project partners if necessary.
Do you procure all aluminum parts from the Constellium network?
The extruded profiles are produced in Constellium factories, the aluminum sheets are manufactured by us and cut to size and shaped by specialists. We purchase aluminum castings and steel sheets from suppliers.
Which customers do you supply from Dahenfeld?
Products from Dahenfeld go to customers such as Audi, BMW, Ford, Jaguar, Mercedes-Benz, Porsche, and Rolls-Royce. These structural body parts are almost all completely manufactured and machined at this plant. An exception are the side collision beams for doors: these parts are pressed and formed in our factory in Singen and only the surface treatment is done here.
Where do you see the greatest market potential?
We still see great potential for aluminum structures in China, where manufacturers still mainly rely on steel bodies. There, enormous substitution effects are still to be expected. By contrast, aluminum is already more widespread among European producers, which means that a high volume growth is no longer expected to occur here. Nevertheless, we also expect promising market opportunities to arise from established manufacturers.
For instance, through electric mobility?
That’s right! Lightweight construction is a must in electric vehicles. On average, the fully electric new vehicles of the next few years will contain about three times as much aluminum as conventional cars with combustion engines.
Could you imagine developing and manufacturing a complete body for electric car start-ups?
Currently, such a scenario is definitely not part of our plans. This requires a lot of know-how in body manufacturing. We certainly have the necessary knowledge in some areas, but by no means in all of them. But I don't want to rule out the possibility that in a decade, depending on how the electromobility market develops, we might find ourselves on this path. We want to properly roll out our current strategy. At the same time, we are positioning ourselves in such a way that we can react flexibly to future developments.
Thank you for the interview.
This article was first published by Automobil Industrie