The best part of speaking with real end-users of additive manufacturing is that it helps us understand exactly what the opportunities and possibilities are for this revolutionary technology. The downside of that is that we don’t always hear what we’d like. That’s often the case in the automotive industry, where the use of AM is not just consolidated, it’s booming in terms of prototyping, tooling, motorsports and one-offs but it also remains very limited (or, rather, non-existent) in terms of direct digital mass production. “AM hardware manufacturers would like automotive companies to scale their use of AM into direct production, but the costs are still very far from competitive with traditional manufacturing,” Dr. Erhard Brandl, Head of the Audi AM Center, confirms. “That said, the possibilities that additive manufacturing is offering in terms of developing the new generation of cars, as we transition towards full electrification, is generating a huge demand of 3D printed parts at Audi.”
Dr. Brandl would know where AM can truly bring benefits. He’s been working with additive manufacturing since 2007 when he started as a Ph.D. student at Airbus in metallic additive manufacturing. In 2012 he moved to Audi to work in Production until, in 2019, he took over the role of Head of the Additive Manufacturing Center. “In my roles at Audi, I started looking at AM from the point of view of an end-user. So, it was no longer important to drive the technology’s evolution as much as actually using it to make parts,” he explains.
The Audi AM Center, located at Audi’s Ingolstadt HQ, is where 3D printing of just about all parts – including all metallic parts – for all of Audi takes place. Dr. Brandl’s team caters to all AM requirements from the Development and Production departments, making sure they get their 3D printed parts in time. They also serve as an internal consultancy, keeping up with rapid additive manufacturing market developments in terms of new materials and applications.
How is Audi using 3D printing?
Audi has been using digital 3D printing in production processes for more than 20 years. Originally, the process was mainly used to produce visual models. In recent years, the share of components created using the technology for the company’s own production tools and vehicle models has increased significantly. In the meantime, plastic and metal have become capable of producing larger and larger parts.
“There’s some physical boundary with scaling up in additive manufacturing because while you can build bigger parts in one run, it may not always be efficient to do so,” Dr. Brandl clarifies. “We do make very large parts, even bumpers, mostly by assembling together different components.
A number of different competencies and resources for Technical Development and Production are pooled at the Ingolstadt site, where the AM Center is located. This is where technology scouting and the development of new applications with various departments take place. There is a second center of excellence for 3D printing using mostly filament extrusion of plastics, which is located at the Neckarsulm site. In close collaboration with Production, 3D printing specialists there design customized assembly aids that make work more ergonomic. If employees have optimization ideas, they can simply contact the in-house 3D printing center.
Together with a start-up from Berlin, Audi has developed software that reduces the time required to design preassembly devices by 80 percent. A sketch is usually all that is needed, and the desired part is available in just a few hours. 3D printing was first incorporated into the preparations for the high-volume production of the Audi e-tron GT1. More than 160 different printed aids are now in use at the location today. One of these, for example, is used in the preassembly of air-conditioning compressors as well as cooling lines. The assembly aid with a built-in clamp was designed in-house and holds all of the components in the exact position.
Developing the future of automotive today
Along with these tools, “the prototyping business represents by far the greatest demand,” Dr Brandl tells us. “It is a major focus area for us because we are undergoing the transition to electrification, digitalization and sustainability. These are major changes and mean that we must rapidly develop entire families of new cars.” Every part that gets manufactured goes through several iterations as it must be optimized with multiple versions before it’s finalized. “Additive manufacturing is a toolbox to help us create new parts faster,” Dr. Brandl explains. “In the past, people didn’t really know additive manufacturing. Now they’re really hungry to use this technology because they really feel that it can solve the real challenges they face in their daily business.”
The metal 3D printing center in Ingolstadt specializes in producing complex steel and aluminum parts as well as inserts for forming tools weighing several tons, for example for pressing car body parts or for die casting. These are manufactured from metal powder using the laser melting process. This makes it easier to implement unusual designs because 3D printing supports greater geometric freedom than any other manufacturing process. This is a major advantage for parts such as tool inserts with cooling channels close to the edge.
“Additively manufactured tools, especially metal tools for hot forming of plastic parts, represent a real serious, Dr. Brandl confirms. “We started with steels and aluminum on several different metal PBF machines, including both EOS and SLM Solutions. We also developed our own parameters. This is a running business with proven business cases because in the end, it’s all about the business. If there is no added value, no cost reduction or other evident benefit in terms of time and quality gains, then, we won’t do it.”
For example, something that Audi will not be using AM for in the foreseeable future is customer-driven customization. “We now know that the customers do not want 3D printed parts, they want solutions,” Dr. Brandl confirms. “3D printing is the ultimate customization tools, but we know that, ultimately, the customer does not want to be a designer: he wants to configure different options which means personalizing but not at the structural level that AM can do. Even in terms of lightweighting, the benefits of AM are not sufficient to justify part costs.
Accelerating on production
So, direct additive production is not something that Audi will be targeting as part of its strategy in the near future, although Dr. Brandl confirms that having a large group such as VW working together on a platform strategy for AM enables the different companies to learn from the progress made by other companies in the group. Altogether this results in a very large number of parts produced across several different AM technologies and while series production is still far away, AM is enabling the development of increasingly complex parts across the entire group.
Batches produced additively at Audi can be as large as 300 or 400 parts and they are used for special projects, from concept models to motorsports, with Audi recently announcing it would enter the increasingly AM-intensive world of Formula 1. “Motorsports are heavy users, but AM remains far too expensive to be used in the broader automotive industry for final parts,” Dr. Brandl confirms. “The price per part must go down dramatically and in the metal area, it’s even farther away because of additional complications due to the removal of support structures.”
While plastics may present more immediate opportunities Dr. Brandl believes that polymer AM also needs to drastically reduce costs to gain adoption. “If we compare it to injection molding, the price of AM parts needs to be reduced by a factor of 100 to 200 times – he says. Some optimizations can be implemented through improved workflows and automation, but even so it remains very far from mass production levels.”
This is not something that Audi can do alone and it’s exactly why the company joined the AMTC conference as a partner and the Bavarian AM Cluster as a founding member. “We need to build strong partnerships and networking to address all these limits of AM,” Dr. Brandl says, adding that we need to build on Germany’s and Europe’s leadership in the AM industry as we transition into a new era for the automotive industry.