Up close and personal with Arcam’s EBM technology

During 3dpbm’s recent visit to the new GE Additive Arcam EBM Center of Excellence in Gothenburg, we had the opportunity to sit down with the two persons in charge of the company’s Technology and Engineering teams: Annika Ölme, VP of Engineering, and Isak Elfström, VP of Technology. Their teams make sure that EBM technology remains the leading AM process it has become, as it now moves more stably into serial production environments. Four years after the momentous acquisition by General Electric, and the consequent establishment of the GE Additive division, Arcam’s EBM technology is flying high, together with former “rivals” Concept Laser in Germany and the rest of the internal GE teams.

“It [the GE acquisition] was a defining moment for us,” says Ms. Ölme. “It has been very beneficial to have a truly industrial owner and to be owned by a company that is also one of our key customers. Aviation has been a key sector for Arcam from the beginning, so we work very closely with GE Aviation and we are now increasingly seen as a very stable and solid player in this segment, which is of paramount importance for aerospace companies.”

At the time of the acquisition, GE did not have an internal additive division – and was definitely not an AM hardware manufacturer – so Arcam’s team was able to continue to build on their capabilities. “It was a very soft transition with no men in black suits coming in to implement new practices,” jokes Mr. Elfström. “We started to interact and looked at how we could grow together. The bottom line is that there are many synergies between Concept Laser and Arcam and we also see synergies with other GE businesses.”

For example, something that most may have never considered is that GE has been using electron beam-based technology in other areas for more than a century, in X-ray based devices such as CT Scanners and other measurement systems. In fact, electron beam generation was invented by GE in 1919. “Among other benefits this means that I finally have colleagues that I can talk to, who know electron beam science and who have built up more than 50 years of experience working with electron beams.” Mr. Elfström points out.

So what’s next for Arcam’s AM technology? The company has built its success on having a sharp focus on two specific application verticals: Aerospace and Medical. The increased strength deriving from working within GE means that Arcam now has the necessary resources to begin targeting more key segments as well. And much like Arcam’s applications for aerospace and medical have been based on titanium and titanium alumide, new segments mean new materials.

The relationship between Arcam and GE dates back to long before the acquisition and is very much connected to titanium alumide. “It [titanium alumide] was initially a GE patented material. When the patent expired, an innovative Italian company called Avio Aero (now also part of GE) – that was already using EBM for their production processes in aerospace – began working on using it in our machines. That proved to work out quite well for TiAl blades aero engine blades production and eventually led to GE acquiring Avio Aero. Which in turn led to GE acquiring Arcam and all three companies now working closely together.

Two recent materials recently introduced for EBM, copper and tool steel, may now serve as the basis to target new segments such as the automotive and the Oil and Gas industries. “Copper, which we have recently presented, is considered interesting for conductive automotive parts while, tool steel is quite relevant for oil and gas, for drill components and other downhole parts” says Ms Ölme. “Historically part of our success has been to focus. Trying to do everything is a danger in AM but we are now able to focus on more things.”

The longer-term future looks even brighter. EBM technology has no inherent physical size limitations and the range of possible materials is quite large. “There are no real limits. We chose to use coarser powder then laser PBF processes only for economic and sustainability issues but we could also process very fine powders if needed,” says Mr. Elfström. “A lot of our university customers use the machine for material development. The University of Texas-El Paso has tons of publications on different materials. The only real limit is that they need to be conductive, which means that some metal-ceramic alloys may not be processable by EBM”.

Other limitations are in calculating where using EBM actually makes economic sense. “For production costs and complexity, the per kilogram price of an aero-engine is the same price of silver”, Mr. Elfström points out. “If you look at the kilo price of an automobile is the same as a hamburger so other GE technologies, such as metal binder jetting, may prove more viable for large part batches.”

The final goal is building tomorrow’s automated, digital, additive factories and in may ways EBM technology is already a few steps ahead. “We feel that most of the process is already quite automated since for about every 80 hours of printing there is about a 1 hour of manual labor to transition to more automated post-processing phases,” Mr. Elfström goes on. “We are of course looking at automating these transitions through automated carts and the new PRS30 powder handling system, which removes 80% of the powder.”

“Another key advantage of EBM is that parts don’t usually require thermal treatment to reduce thermal stresses since the thermal gradient during the build process is very low. Users may want to do heat treatments but only to improve the microstructure of the part.”