GE Additive has had an impressive showing at Formnext this year, presenting new AM systems in its Concept Laser and Arcam families and more. On the Arcam side, GE Additive has also announced the upcoming general release of development material (D-material) support for pure copper and highly alloyed tool steel in 2020.
Across the AM industry there has been a growing demand for metal materials, including pure copper and tool steel. To address this, GE Additive is offering a D-material that “describes the maturity of process parameters for a specific material or family of materials.” D-materials can be used to print test bars in limited build envelopes to assess the new materials before moving into industrialization.
“This general release of D-material support for pure copper and tool steel is an exciting development and opens up EBM to wider range of industries and applications,” explained Karl Lindblom, General Manager of Arcam EBM. “We have opted to take an open, collaborative approach and will review feedback from customers using the D-material, and gauge their long-term interest, before considering how we approach industrializing the materials.”
Following the D-material phase—and assuming all goes well—the company will need to conduct additional development to create an “industrialized material” (I-material) that can be used to produce complex geometries. At this stage, the material will also necessitate the creation of process parameters optimized for specific customer applications. GE Additive AddWorks can provide guidance for establishing process parameters, though customers may opt to create them in house.
3D printing pure copper
Pure copper is a notoriously difficult material to work with using laser-based AM processes because of its high reflectivity. Because of this, many in the industry have come up with copper-based alloys which, while easier to print, lose some of copper’s conductivity properties. GE Additive’s Arcam EBM process, however, can print pure copper.
This is because of the use of an electron beam instead of a red laser. According to GE Additive, pure copper can absorb 80% of the electron beam’s energy while it only absorbs 2% of the energy of a red laser beam. Another aspect of the EBM process which enables it to print pure copper is its vacuum environment, which minimizes the oxygen pick-up in copper. Because oxygen reduces the conductivity of copper (and causes embrittlement), the vacuum environment can result in parts with higher conductivity.
The capability to 3D print pure copper in complex geometries could present advantages to many industries—including automotive—in the production of electrical connectors, induction coils and heat exchangers.
3D printing tool steel
For different reasons, high carbon level steels have been challenging to 3D print because of their tendency to crack when exposed to large temperature gradients—characteristic of PBF processes. EBM, however, is reportedly the only commercial AM technology that can print crack prone alloys because of its high build temperature.
EBM’s vacuum environment also helps in printing tool steel as it protects the material from impurities.