AMGTA
AMGTA explores sustainability of metal AM feedstock
The Additive Manufacturer Green Trade Association (AMGTA) has announced the preliminary results of a research project exploring the sustainability of metal additive manufacturing feedstock.
The study, titled “Specific Energy of Metal AM Feedstock: A Comparison,” was conducted with Syntec Associates in partnership with Divergent Technologies to determine specific energy requirements for producing metal 3D printing materials via three key approaches: gas atomisation, mechanical milling (specifically ball milling), and wire drawing.
The study found helium gas atomisation to be the most sustainable method used for metallic powder production of commonly used alloys, followed by argon and then nitrogen, from an energy perspective. The findings highlighted that specific energy consumption for atomisation also critically depends on process parameters and alloy chemistry. Additionally, research showed that mechanical milling outperforms gas atomisation and demonstrates a significant reduction in specific energy consumption.
“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,” said 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 research revealed that gas atomisation using helium resulted in the least total specific energy consumption compared 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).
“This important piece of research provides guidance on which methods of gas atomisation require the least amount of specific energy per kilogram,” said 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.”
Ball milling showed approximately a 90% improvement in specific energy consumption compared to gas atomisation for the range of process conditions studied, though further research is recommended to determine the applied impact within specific product categories of using helium-atomised powder and/or ball milled powder.
Sherri Monroe, the AMGTA’s Executive Director said: “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.”
Last year, AMGTA carried out a lifecycle assessment study on a luxury designer shoe application which found that CO2 emissions could be reduced with 3D printing. It follows the completion of two other LCA studies commissioned by AMGTA, with the first assessing the environmental impact of using AM for a low-pressure turbine bracket, and the second measuring the environmental impact of a 3D printed steel scroll chiller in an HVAC system. The AMGTA says it expects to publish additional independent research throughout 2024.
