3D Printed Pistons Deliver High Performance
Zeiss came up with a unique quality assurance process to manufacture 3D printed pistons for the high-performance engine of Porsche's 911 model – the GT2 RS. Numerous solutions were used by the company to analyse the quality of the powder, identify defects and examine the final quality of the components.
Additive manufacturing offers enormous potential for optimized and new components alike. At Porsche, 3D printing technology is already being employed in several areas. And now, a joint project from Porsche, Mahle and Trumpf, in cooperation with Zeiss, has successfully 3D-printed highly stressed drive components for the first time, using generative processes to manufacture pistons for the high-performance engine of Porsche's top-of-the-line 911 model: the GT2 RS.
The entire team headed by Porsche project lead Frank Ickinger is more than pleased: "This makes a performance boost of up to 30 horsepower conceivable with the 700PS twin turbo engine, and with higher levels of efficiency at that." The "printed" high-performance piston project is a total success. A milestone in the history of additive manufacturing.
As in motor sports, the development and manufacture of the components is a team effort. The project is headed by Porsche. Mahle, a cooperation partner of the project, provides the requisite know-how for the development and manufacture of drive components and for additive manufacturing. Trumpf is the project's specialist for additive manufacturing systems, colloquially known as 3D printers. The quality and performance of the materials used and of the components is ensured by means of solutions from Zeiss.
Quality assurance is essential across the many individual steps of the manufacturing process, from powder to finished component. To meet the specific requirements of this kind of manufacturing, a comprehensive quality assurance process was developed by Zeiss. The goal of the project, apart from manufacturing the piston prototypes and thus improving the efficiency of the components, is to develop an additive manufacturing process capable of meeting the highest quality standards while remaining lean and cost-efficient to make series production possible. This process will ultimately be used for the manufacture of other components as well.
With this piston material in particular, which had never been printed before, it was of course a challenge to generate the right component quality. With the help of Zeiss, we were able to do this very well.
Challenge to Generate the Right Component Quality
At the foundation of this manufacturing process is a metal powder made from a special alloy developed by Mahle. The powder is applied layer by layer inside a metal 3D printer from Trumpf and fused at selective points using a laser. Over the course of 12 hours, 1,200 layers are applied to form the piston blanks. To ensure that the 3D printed pistons meet the high requirements, a comprehensive quality assessment is needed. "With this piston material in particular, which had never been printed before, it was of course a challenge to generate the right component quality. With the help of Zeiss, we were able to do this very well," summarizes Ickinger from Porsche's Advanced Engineering Powertrain division.
Enhancing the Design
A big advantage of this process is that it enables the creation of a novel bionic architecture. Topology optimization is used to simulate the load paths and hence to define a structure appropriate for the load. As such, the advance development project is able to achieve a weight reduction in its pistons of 10 percent as compared to the welded series pistons. The 3D printed piston prototypes also feature an integrated cooling channel — this would not be possible with standard manufacturing methods. "With the new, lighter pistons, we are able to increase engine speed, reduce thermal load and optimize combustion," explains Ickinger.