Metallic 3D printing systems have already begun to create a world of new possibilities in the areas of development, design and production. The technology is now finding a home in exclusive mass production as well.
It all sounds futuristic and is certainly a fascinating sight to behold: a 3D printer that produces highly complex metal parts from virtually nothing, so to speak. The printer first applies layer after layer of razor-thin metal powder and then fuses the material into a component with the help of a laser ray. The process pays off in one big way: It can produce highly complex components that were impossible to make in the past with conventional processes – and it can do so in record time.
Does the future of car production lie in 3D printing?
Jörg Spindler, the Head of Equipment and Metal Forming at the Audi Competence Center, answers this question by trying to calm the euphoria. To do so, he makes a comparison with carbon components: “Carbon-fiber-reinforced polymer didn't knock steel sheets out of the game. Rather, it created new possibilities,” Spindler says. “Metallic 3D printing is also not a competing process in mass production. But it will certainly lead to significant progress in some sub-areas.”
The technology has already revolutionized production of prototypes, creating a component directly from the design drawing. Knuth Walczak, the Head of Innovation and Advance Development Management in the E Department at Porsche, says of the technology: “3D printing is already saving tremendous amounts of time in terms of the very small lot sizes used in development and auto racing. Other strengths of the process include reducing weight and helping in areas where a component will take on additional jobs like cooling or air flow.”
As a result, tools used for hot forming, plastics injection molding or die-casting applications with conformal cooling channels under the surface whose improved cooling leads to reduced process times can be produced. The example also shows that 3D printing faces no limits in terms of durability. Knuth Walczak: “No direct weakness is created in material properties. Even highly stressed parts like pistons can be printed. Because the material is laid layer upon layer, you can systematically affect the microstructure. The mechanical properties differ significantly from those of conventionally produced parts.”
A research project being conducted by Volkswagen Osnabrück is demonstrating just how much potential lies in the area of weight reduction. In work to reinforce an A-pillar, the number of individual parts and, as a result of the bionically optimized design of the component, the weight could be reduced by 74 percent – while maintaining the same level of durability.
Despite these strengths, the use of metallic 3D printing will remain limited to special application areas for the time being because the process is relatively slow and expensive. Dimensional accuracy and finish quality need to be improved as well. In extreme cases, it can take more than 100 hours to print a prototype engine block. The rule of thumb for the technology is: Smaller, more complex and less cost sensitive parts are better suited for 3D printing.
Special and exclusive series made by Volkswagen are well suited for the use of metallic, 3D-printed components. The first parts in these areas are now being produced by metallic 3D printing.
Original replacement parts that are rarely needed are also being reproduced today by 3D printers. Such parts include a gearstick for the legendary Porsche 959 or a water connector for Audi’s W12 engine. Alexander Schmid, a member of After Sales and Sales at AUDI AG, says: “Reproduction on demand is a vision for us. In the future, we will be able to economically and sustainably ensure supply with fewer original replacement parts. Regional printing centers will simplify logistics and warehousing operations.”
Like many new technologies, much work still must be done here before prototypical applications can make the leap to mass production uses in the automaking industry. Jörg Spindler says: “Today, 3D printing pays off when you make up to 200 units throughout the life cycle of a product. With the help of optimization in process and plant engineering, we will be able to reach cost effectiveness at a level of 3,000.” In turn, cost reduction would open new ways to customize vehicles, like special performance models in exclusive series.
Strong technology, strong community
Researchers have made 3D printing one of their highest priorities, even if such a printer is unlikely to ever produce a complete Golf. Ingo Hartmann, of Volkswagen Group Research, says: “At Group Research, we spend a lot of time considering the extent to which 3D printing vehicle concepts will impact future generations. One particularly interesting area is the new freedom in design that we plan to tap and produce the maximum benefit for the customer.”
Ingo Hartmann is also responsible for networking 3D activities within the Group. The Group Technology Unit was set up nearly four years ago. It has nearly 100 members from all business areas in the Group, including developers, designers, production specialists and sales representatives. Members of this community are particularly proud of the exemplary cross-brand collaboration it practices. Hartmann says: “We encourage open discussion of ideas and use flat hierarchies. A pioneering spirit has arisen in the group from the challenging job to shape the development of a new technology. You could say that we are bringing the Group’s ‘TOGETHER’ strategy to life.”