• 27 – 29 September 2022
  • Exhib. Centre Düsseldorf

"We will provide insights into the future"

May 3., 2022

Where is additive manufacturing heading? And why is it inevitably an important topic at ALUMINIUM? RWTH Professor Johannes Schleifenbaum in conversation.

ALUMINIUM: Mr. Schleifenbaum, the topics of digitization, networking and sustainability play a role in the mission statement of the Aachen Center for Additive Manufacturing. How does ACAM interpret these terms?


Johannes Schleifenbaum: To start with networking: As a classic Campus Center, ACAM has the function of making certain topics and research focuses available to industry. We are a gateway for industry to access various research results through this organization. And we do this in the form of integrative, close collaboration. So it's about transforming knowledge into industrialization and ultimately casting it in value creation.

As far as digitization is concerned, it's important to emphasize that this process has no defined end - even if some people think it does. In my view, a key aspect here is the shift from time-driven to event-driven operation: predictive maintenance, for example, is the move away from fixed maintenance intervals in the direction of data-based analysis of the machine's condition. And this is where additive manufacturing comes into play, in a sense as the real twin of digitization. And this brings us to the aspect of sustainability.



Johannes Schleifenbaum holds the chair for Digital Additive Manufacturing at RWTH Aachen University.

ACAM Aachen Center for Additive Manufacturing, based on the RWTH Aachen Campus, pools resources and facilitates industry’s access to the Additive Manufacturing expertise of leading scientific and research institutions.

ACAM is the one-stop-shop for Additive Manufacturing, covering the entire process chain, from design stage through to quality control and focuses on topics such as process chain automation, the development of customized materials, increasing productivity and reducing turnaround times.

How does this bridge look like?


Schleifenbaum: It's about the net economic benefit of digitization. We can afford to simply own products but not use them. Most goods today have utilization rates in the single-digit percentage range. So the obvious thing to do is to increase the efficiency of use. I think we are at a threshold where digitization can actually generate real economic net benefits for the first time: by synchronizing customer behavior with producer behavior. We need to move from push-driven overproduction to demand-driven production. I see the vision of using individualizable, flexible processes to supplement established processes in such a way that we waste our resources as less as possible. Quite simply, we have a duty to offer something here.


Additive manufacturing was long considered a playground for nerds, then established itself in prototyping and then in the area of spare parts production. That's probably not the end of the development?


Schleifenbaum: No, certainly not. I think real fire came into the topic in 2011 when the Economist ran a cover story on a printed, playable violin. The title was "Manufacturing Technology that will change the World." Many concluded at the time that we would soon be printing everything, that even printers would be printing each other, and that, like Captain Picard, we would soon be getting our Earl Grey from the replicator. Of course, that's not how it will turn out, but the story attracted attention even from people who think in terms of business cases.

At the same time, of course, there was headwind. Machinists in particular have learned that life begins with a center line, with symmetry. Many designers have been trained for decades to think and design in such manufacturing systems. And now tell them: What you did for 30 years was good, but it's over now.

We still face this challenge today: The capabilities of technology do not find sufficient influence in the possibilities of design. Spare parts that are rare and expensive are printed. But the real kicker comes when functions in products, typically reflected in assemblies rather than individual components, pay off over the entire life cycle.

„I think we are at a threshold where digitization can actually generate real economic net benefits for the first time."

But the idea that it's about far-reaching substitution of other manufacturing technologies is probably outdated?


Schleifenbaum: Additive manufacturing can and will have a complementary effect in many areas. For example, we are already seeing burner geometries that allow the switch from 100 percent natural gas to 100 percent hydrogen, and they simply cannot be produced any other way. A lot of it exists only in the initial stages - but if we don't start today with the spare parts and the simple geometries, we will be overtaken by others, and then we will find ourselves at a competitive disadvantage.


Do you see a danger of technology slipping out the bottom of the famous Gartner curve?


Schleifenbaum: It's important to emphasize here that additive manufacturing is the widely accepted collective term for about 25 different technologies that build digitally and layer by layer. 3D printing is just one of those technologies. And no, the valley of tears has long been overcome, the technologies are in productive status. Thousands of hip implants are printed every year in Germany alone, and that's perfectly acceptable. Other technologies, such as live-cell printing, are only relatively far at the beginning, but in principle the topic is established.


How important is research into and the development of new materials?


Schleifenbaum: About five years ago, an important door was opened with Scandium Alloy. With this alloy, it was possible to stabilize the material thermally and mechanically. In other words, properties that almost go in the direction of a titanium alloy. This development had a similar effect to the Economist story: We can also manufacture with materials that explicitly use process kinetics to achieve better properties. This journey has just begun. All the major manufacturers have an agenda with numerous materials, some of which are further developments of existing materials. There will be a lot more to come here, but here too, of course, you have to take people along with you.


How much of a role can aluminum play here in general?


Schleifenbaum: I have already mentioned Scandium Alloy. But there are a number of exciting developments. For example, in the direction of using the extremely fast solidification kinetics to increase temperature strength. I think it is very exciting to develop systems that are expressis verbis suitable for high temperatures and that combine good strength with good residual elongation at fracture.

„All the major manufacturers have an agenda with numerous materials, some of which are further developments of existing materials. There will be a lot more to come here, but here too, of course, you have to take people along with you."

At ALUMINIUM in the fall, user industries will also be represented, for example from the new mobility, aerospace or even the building and construction sectors. What can the combination of aluminum and additive manufacturing achieve here?


Schleifenbaum: In the new mobility concepts, everything is naturally aimed in the direction of moving less mass, since this immediately generates an energy and resource benefit. Here, aerospace is probably more of a pioneer than ground-based mobility. In the area of Urban Mobility, we are looking at many exciting concepts - we will see what will prevail here in detail.

The construction sector is an important research area for us. The processes in the cement industry in particular emit a relatively large amount of CO2, so the question of what recycling could look like in the future is naturally very exciting. At present, material is torn out, separated and shredded - this is highly unfavorable in terms of energy. It would be more interesting to preserve the structures, and here the facade in particular is exciting. I don't think we'll be printing entire facade elements in the future, but certain standard elements such as tubes or bar profiles in various lengths and dimensions could be combined and joined together with nodes, soldered, welded, riveted, whatever. These nodes could be printed directly on site. This would be a form of customization that preserves the stock.


Why does ACAM actually cooperate with ALUMINIUM in Düsseldorf?


Schleifenbaum: In a way, I myself have a dual function here. As employees of the RWTH, we are called upon to maintain and increase prosperity in Europe, and to do so in the most sustainable way possible. Innovation and progress are therefore the mandate of my actions. And since innovation, as we all know, does not only have friends, we also have to communicate. So it's an explanatory task, and it can't just stay in the realm of science, it must also be carried into industry, into the national economy. It must find users, inspire users. Of course, such trade fairs are ideally suited for this purpose.

As employees of ACAM, we are carriers of information, but we also have to know the problems, the issues, otherwise we remain in the ivory tower. Time and again, we find solutions for which there are no problems at all. But if we receive feedback, then we can work very specifically on solutions.


What can visitors to the trade show expect from you in concrete terms?


Schleifenbaum: We will provide insights into the future. Not because we are smarter than others. But we have the privilege of dealing with topics that typically happen in the future. At the same time, we are happy to discuss specific, current problems. For some we will be able to offer solutions, for some we will work together to find solutions. Conversations are always the first impetus to really start something new.

Interview: Bernhard Fragner