The use cases for three-dimensional printed automobile parts are plentiful, but significant production applications of the additive manufacturing process have been almost non-existent in automotive—until now.
Multiple European OEMs are preparing to produce select interior and exterior components via additive manufacturing in 2018. These low-to mid-volume runs will represent a milestone for constructing a part directly from 3D CAD data with each part being built up layer by layer from powders.
“A production vehicle application is maybe a small thing for the auto industry, but it’s a breakthrough for additive manufacturing,” said Fabian Krauss, Business Development Manager for Electro Optical Systems (EOS) GmbH, an additive manufacturing equipment and solution provider. Krauss and other officials spoke with Automotive Engineering during a recent advanced manufacturing seminar hosted by EOS in Novi, Michigan.
Using 3D printed parts for a production vehicle application means meeting rigorous requirements.
“To produce spare parts, you don’t need a full qualification. For [assembly floor] aids, you don’t need a qualification," Krauss said. "But to be on a commercially sold vehicle, you need a full qualification. And that means the additive manufactured parts [coming in 2018] passed the qualification. That’s a major breakthrough.”
He noted that the aerospace industry took seven years to pass qualification with 3D-printed/additive manufactured parts. Achieving qualification requires thousands of test coupons. The coupons undergo a series of evaluations, including being torn apart, fatigue checked, and precisely measured.
“A quality engineer needs to sign-off that an additive produced part has the same properties, or better properties, when compared to a conventionally manufactured part. There are no quality shortcuts,” Krauss explained.
One prominent early use of 3D printed parts on vehicles is motorsports. Krauss points out that select additive manufactured parts, made from carbon-filled polyamide, were used on race cars competing in the 2017 Deutsche Tourenwagen Masters (DTM) touring car series. In 2016, the Williams Martini Racing Formula 1 Team used EOS technology to produce plastic air-deflecting parts on the front wing’s exterior.
“If you can perform in racing, which puts a high stress on components, then those components can often manage the stress associated with driving a mass-produced vehicle,” Krauss said.
Proof through prototyping
Producing one-off components or small batches of parts has been a hallmark of 3D printing. The manufacturing technique can provide a solid 3D model of virtually any geometric shape. For automakers and suppliers, the ability to produce large parts quickly can be a major assist during product development. A quick turn-around timetable is especially relevant for investigating a new design’s potential, explained Lindsay Lewis, Account Manager for Synergeering Group LLC, a prototyping services company.
“In just a week we can build a large part, such as a front fascia with all the needed brackets and underbody pieces,” said Lewis. When attached to a vehicle body, a full-size front fascia prototype is ready for wind tunnel testing. That’s especially relevant for a new vehicle model or a mid-cycle vehicle refresh. And by using an automaker’s CAD data, additional design iterations can be produced.
“We’ve seen customers evaluate multiple front fascia designs to determine which particular design has the preferred aerodynamic performance,” she said.
Requests for fascias, engine components, and other functional prototype parts have become more commonplace since the Synergeering Group’s beginnings in 2001. The firm’s RapidNylon process uses a glass-filled nylon blend that mimics the material used in injection molding operations. And the company’s novel post-processing method elicits airtight parts that are impervious to oils, coolants, petroleum, brake and other fluids.
CAD data can also be used to add threaded inserts, compression limiters, self-tapping screws, and other elements after an under-hood prototype part is built. “Engineers use functional prototypes to prove out their designs and make any necessary changes before cutting a production tool,” Lewis said.
A team of companies headquartered in Germany and the U.S. recently employed industrial 3D printing to create a light vehicle front-end concept structure, using an early Volkswagen Caddy pickup as platform. Engineers and technical specialists from Altair, Airbus Apworks GmbH, csi entwicklungstechnik, EOS GmbH, GERG, and Heraeus went from design to a finished front-end module in nine months. Unveiled in 2017, the Caddy front-end includes parts that are load-bearing structures. Other elements include a channeled airflow to cool the batteries and brake systems as well as integrated functions relating to heat management, passive safety, and fluid storage.
Engineers and technical specialists from the six companies handled all development steps from design, simulation, optimization and manufacturing to post production.
Optimizing for production
The ability to construct a highly complex shape is one of additive manufacturing’s drawing cards. Tony Norton, Altair ProductDesign’s Executive Vice President of the Americas, said additive manufacturing is well-suited for making lightweight parts. “But if you are just going to substitute additive manufacturing for a subtractive/traditional manufacturing process, you have just really lost the opportunity to take advantage of the technology,” Norton said.
Since the 1990s, Altair’s suite of topology optimization software tools have been used by automotive engineers to design lightweight components produced by traditional manufacturing methods. “Through topology optimization, an engineer can create very organic-like structures. But when you blend topology optimization with additive manufacturing, an engineer can create a very lightweight part that can withstand the loads and fit within the available packaging space,” said Norton.
For additive manufacturing to become a series production staple, the automotive industry will need to become more knowledgeable about the production process, according to Scott Volk, Director of Additive Technologies & Innovation at Incodema3D, a contract manufacturer specializing in additive manufacturing.
“The North American auto industry needs to gain confidence in all aspects of additive manufacturing before it will be considered for series production,” Volk said. It also would take a major cultural change in the global automotive industry as injection molding, CNC machining, and other traditional manufacturing processes have been the status quo for decades.
The aerospace industry has produced various non-critical parts via 3D printing technology, but large-scale production of major components is likely another one to two years from reality.
“Right now, the aerospace and medical industries are bearing the burden of investing in the knowledge that’s needed in order to embrace 3D printing technology,” Volk said. Altair’s Norton agrees that the automotive industry is not at the forefront of using additive manufacturing for production parts. “The aerospace industry has been more engaged with additive manufacturing in large part because the volumes are lower,” said Norton, “However, we do see movement in the automotive industry to apply additive manufacturing to tooling.”
Connecting for the future
Additive manufacturing is a centerpiece of GKN Group’s pilot production plants. In a broad sense, these plants will follow the Industry 4.0 approach to manufacturing with a focus on automation and data exchange to elicit a ‘smart’ factory. “Additive manufacturing lends itself well to the concept of digital manufacturing and Industry 4.0,” said Josh Norman, GKN Sinter Metals’ Global Product Center Manager for Additive Manufacturing North America.
Initial pilot plant locations include Bonn, Germany and Filton, England. A U.S. plant with an Industry 4.0 layout concept is planned, but a site hasn’t been announced publicly.
“Large-scale additive manufacturing isn’t a reality yet. But that will shift as the additive process becomes faster and as the automotive industry embraces the unique design capabilities the technology offers,” Norman said.