Page 18 - 3D Metal Printing Summer 2016

3D 3D Metal Printing Revving Up the Auto Industry
Formula 1 teams have long-used
3D metal printing to improve
component performance and shave weight from their high-performance cars. For example, the weight of this aluminum axle pivot was reduced by 660 g and rigidity increased by 20 percent compared to a conventionally
made part. Source: Rennteam Uni Stuttgart.
by Materialise. Its RapidFit company 3D- prints modular check fixtures for auto- motive applications, using a variety of materials including an aluminum- polyamide powder called Alulon. Com- pared to traditionally fabricated fixtures, the RapidFit fixtures are significantly (as much as 50 percent) lighter, and can be designed with complex internal and exter- nal geometries.
A Raging Racing Success
On the direct-metals front, the EOS website offers up a handful of Formula 1 applications for 3D metal printing. Includ- ed is a 3D-printed driveshaft combining carbon fiber and titanium that reduces weight by 73 percent compared to a steel driveshaft; and a wheel-suspension part printed from aluminum that reduces weight by as much as 35 percent com- pared to the previously used investment- cast part.
“There are several examples out there,” adds Snow, “and most are proprietary. Another one I’ve seen is a custom gas pedal printed as a titanium lattice.
“To move metal-AM technology more into the mainstream automotive market, including short-run production of low- volume cars,” Snow continues, “we’ll need to see a continuing of the evolution underway in areas such as part design, deposition rate and in-process quality control.”
Describing programs in place to devel- op the metal-AM knowledge base of next-
generation design engineers, Snow notes work underway at several universities including the University of Louisville, which has partnered with Underwriters Laboratory as well as EOS. Such programs help to train the next generation of engi- neers in the economics of AM, basic machine operation, material handling and design for AM. Such training is needed because the design rules that apply to tra- ditional subtractive machining do not necessarily apply when using AM.
“The industry also is developing tech- nology to significantly increase metal dep- osition rates,” Snow continues, “which will help automakers and their suppliers cost-justify use of the technology. For example, EOS recently introduced a machine (the M400) that can be equipped with as many as four laser heads. The beams can work simultaneously to build up one part, or can individually build multiple parts at one time.”
Process/Quality Control
Other much-discussed areas when it comes to moving 3D metal printing into production applications are production- monitoring and process-control technolo- gies. Here, EOS also is busy. Late last year the firm rolled out its EOState melt-pool
monitoring system that collects data relat- ed to every layer built up during the DMLS process.
“Reproducibility is key if we’re going to grow the use of metal AM, particularly in industries where part-quality assurance is critical, such as in automotive,” says Snow. “This technology lets customers move part quality assurance from post- process to in-process, which promises to increase productivity and reduce overall costs.”
The process works by observing and gathering data related to the light emitted by the melt pool. Software then analyzes the data to help direct process parameters.
Last but not least, EOS expects to intro- duce, early in 2017, an optimal tomogra- phy setup that will monitor the powder bed during processing and capture 3D images of the workpiece. “Using the process, developed in Germany along with aerospace company Munich Turbine Union,” Snow says, “we’ll be able to iden- tify any inclusions or other flaws that might have developed during the build. This will help manufacturers make quicker and better defined decisions regarding the secondary processes that might be required after printing—hot-isostatic pressing, for example.” 3DMP
16 | 3D METAL PRINTING • SUMMER 2016
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