AMGTA releases preliminary research on sustainability of powder and wire additive feedstock
April 25, 2024
The Additive Manufacturer Green Trade Association (AMGTA), a global advocacy group focused on promoting sustainable Additive Manufacturing industry practices, has announced the preliminary results of a research project titled ‘Specific Energy of Metal AM Feedstock: A Comparison.’
The study, commissioned by the AMGTA and conducted by Syntec Associates, a research consultancy, in partnership with Divergent Technologies, evaluated three key metal Additive Manufacturing feedstock processing approaches – gas atomisation, mechanical milling (specifically ball milling), and wire drawing – to determine specific energy requirements for producing feedstock materials.
The research findings highlighted that, from an energy perspective, helium gas atomisation is the most sustainable method used for gas atomisation for metallic powder production of commonly used alloys, followed by argon and then nitrogen. Specific energy consumption for atomisation also critically depends on process parameters and alloy chemistry. Additionally, research showed that mechanical milling, when appropriate for use in powder production in Additive Manufacturing, exhibits a significant reduction in specific energy consumption when compared to gas atomisation.
“When preparing life cycle assessments on industrial rate processing of our alloys, I found wide variation in the literature on AM process and powder atomisation energy consumption,” shared Michael Kenworthy, Chief Technology Officer at Divergent Technologies and AMGTA Board Director. “This research established a transparent set of process assumptions and models from which to understand the key process levers and evaluate system trade studies that inform future sustainability enhancements.”
The following takeaways from the study were noted:
- Helium gas atomisation is best for powder atomisation: Research indicates that, from an energy perspective, helium gas atomisation stands out as the most sustainable gas atomisation method, showing a significant reduction in specific energy consumption compared to argon and nitrogen for commonly used alloys
- Argon atomised powder is better than nitrogen: For those seeking an alternative to helium, argon-atomised powder is revealed to be a notable option, energy savings when compared to nitrogen-atomised powder
- Mechanical milling outperforms gas atomisation: Mechanical milling, particularly ball milling, demonstrates a significant reduction in specific energy consumption compared to gas atomisation for metal AM powder production
- Industry guidance for sustainable choices: This research highlights the importance of selecting manufacturing methods with the lowest specific energy consumption per kilogram to enhance overall sustainability when producing feedstock materials used in Additive Manufacturing
“A primary goal of the AMGTA is to educate the consumer on the most sustainable methods of production within the additive supply chain. This important piece of research provides guidance on which methods of gas atomisation require the least amount of specific energy per kilogram,” stated Brian R Neff, AMGTA’s board chair. “At the same time, it indicates to the market that mechanical production methods of powder feedstock, such as ball milling, are themselves an order of magnitude better than gas atomisation from an energy perspective.”
Gas atomisation, deemed a promising technology for producing stock powders for Additive Manufacturing, was a focal point of the study. The research revealed that the gas atomisation using helium as the atomisation gas resulted in the least total specific energy consumption in comparison to argon (13% better on average) and nitrogen (28% better on average). Additionally, argon-atomised powder was found to reduce energy requirements by 12% when compared to nitrogen-atomised powder for the alloys studied (SS316L, Al5083, and IN718).
The study also highlights the efficiency of mechanical powder production, particularly ball milling, which showed approximately a 90% improvement in specific energy consumption compared to gas atomisation for the range of process conditions studied. Further research is recommended to determine the applied impact within specific product categories of using helium-atomised powder and/or ball milled powder.
“This research aligns with the AMGTA commitment to better understand sustainable manufacturing practices leveraging additive technologies,” commented Sherri Monroe, the AMGTA’s Executive Director. “These findings highlight key considerations for manufacturers seeking environmentally friendly feedstock production methods. To advance sustainability in Additive Manufacturing, research is vital in order to make informed decisions.”
Read the full report, here.
Download Metal AM magazine
