Last week, B&B sent an engineering team to the RAPID Expo in Detroit, Michigan. This is an event which showcases the latest 3D printing processes and is a key to increasing our knowledge of the current state-of-the-art of additive manufacturing. This year, we were pleased to see that the show was 50% larger than in 2013. About 150 companies were on-hand and, even better, there were far fewer hobby or personal 3d printer exhibitors and more presentations directly related to large scale manufacturing.
One of the additive manufacturing technologies we were investigating was Direct Metal Laser Sintering (DMLS). This technique uses a laser to sinter powdered metal, layer by layer, into a finished, solid structure. Typically, inside the build chamber a build platform is recoated with new material after a laser moves through the cross-section. The focused beam melts the powder locally and builds up a layers only micrometers thick allowing for complex geometries which would be difficult to achieve with conventional subtractive manufacturing techniques.
We spoke with six system manufacturers, evaluated their processes and learned about design challenges, processes, capabilities and best practices in this fairly new field. Some of the more interesting technology advancements were:
New “compression” technology compresses the media layer just prior to sintering. This is said to improve the “realized” resolution of the sintered for while allowing unsintered media to provide greater support, reducing structural support needed by other techniques. They also showed off the addition of a secondary loading chamber on their high-end ProX 300.
They were a newcomer but were the first to present a system which employs both additive and subtractive technology in one platform. We found ourselves pondering some issues with the process such as part movement related to tooling pressures, chamber environment control, media contamination from chips and output integrity from chips being refused. Overall, this was an interesting solution and we will be interested in seeing how it evolves.
Having recognized a need to inspect printed features which cannot be seen with the naked eye, Nikon has integrated their x-ray technology with their scanning technology. Just brilliant!
Overall, the current use of additive techniques for metallic outputs is still heavily focused on medical and dental industries or one-off prototypes. One system distributor put it well,
“Old school design engineers are having difficulty breaking away from their “xy” ways of thinking, and therefore are very skeptical to venture into this new technology… Furthermore, the ability to control material properties is no longer an issue, and they need to see that! Thankfully the new generation of engineers have an innate ability to see the advantages, quickly adopt new ways of thinking, and are beginning to influence the “in place” ways of thinking – large scale adoption is only a matter of time.”
It is still early days with additive manufacturing but the potential of these technologies is immense and the number of solutions is growing. In past years, we had to find the few exhibitors who were showcasing this technology. This year, it was hard to find an exhibitor who was not and it was encouraging to see so many companies promoting metallic printing capabilities.