According to a recent joint study between Direct Metal Laser-Sintering company, EOS, and the European Aeronautic Defense and Space Company (EADS) Innovation Works (IW), additive manufacturing (AM) can reduce the costs of building and operating aircraft. The study examined CO2 emissions, energy and raw material efficiency, and recyclability in the production and use of a single part made with traditional manufacturing compared with that same part made via AM, finding that 3D printing can offer important benefits.
According to the two companies, the study was comprehensive in its scope: “when analysing energy consumption, the company’s investigation included not only the production phase, but also the sourcing and transportation of raw materials, argon consumption for the atomisation of the DMLS metal powder and overall waste from atomisation.” The tests were carried out in relation to the production of Airbus A320 nacelle hinge brackets and the data was reinforced both by EOS and a raw material supplier.
The researchers compared the production of an optimised titanium hinge bracket made with rapid investment casting versus an optimised titanium bracket made using DMLS with an EOS machine. While the team found that: “energy consumption for the life-cycle of the bracket, including raw material manufacture, the production process and the end-of-life phase, is slightly smaller on the EOS platform compared with rapid investment casting,” they saw a significant advantage in using 3D printing when it came to raw material waste and CO2 emissions.
The results of the study concluded that: “the additive process uses only the amount of material for manufacture that is in the product itself. Thus consumption of raw material can be reduced by up to 75 per cent.” And, because the AM part was able to reduce the overall weight of the aircraft by about 10 kg, “CO2 emissions as a result of the brackets were reduced by almost 40 per cent over their life cycle by optimising the design, despite the fact that the EOS technology uses significantly more energy during manufacture.” These findings echo similar outcomes of 3D printing relayed by GE in the examination of their LEAP engines.
The ALM Research Team Leader at EADS IW, Jon Meyer, believed EOS’s technology to have a lot of potential, saying:
DMLS has demonstrated a number of benefits, as it can support design optimisation and enable subsequent manufacture in low volume production. In general, the joint study revealed that DMLS has the potential to build light, sustainable parts with due regard to our company’s CO2 footprint. A key driver of the study was the integrated and transparent cooperation between customer and supplier, with an open approach that saw an unprecedented level of information sharing. The collaboration has set the standard for future studies involving the introduction and adoption of new technologies and processes. Even after the first positive results were evident, neither of the parties settled for the outcome, but continued to investigate options for further improvement.
There are a few important points of note to be made about the study. First, it was made clear that “the study focused on the comparison between DMLS and rapid investment casting of a single part and did not take into account the question of scalability, which has yet to be addressed.” The study also explains that: “the EOS technology uses significantly more energy during manufacture.” Because most nations are still tied to a fossil fuel energy grid, this fact of the study is not to be overlooked. If AM technology uses more energy than traditional methods and that energy is derived from coal, natural gas and oil, the overall CO2 emissions of the production method itself are detrimental to the Earth’s atmosphere. This is not necessarily a problem with direct metal laser sintering, per se, as other green technologies, like solar panels, are produced using energy from the same ecologically harmful methods as additive manufacturing.
Also of interest is the image that performing such a study might have for a company like EADS IW. The study does not illustrate that, while the aircraft themselves produce less CO2 from 3D printed parts, what they might be used for (outside of civilian transport) is tremendously bad for the environment. EADS is a defense manufacturer and, as such, contributes to environmental destruction in a number of ways. The list of negative impacts that war has on the environment is a long one that includes devastating local flora and fauna, the use of deadly chemicals, damage to infrastructure and the pollution of drinking water, and pollution via the use of fossil fuels.
The move to use less fuel-hungry technology by companies like EADS (and GE) is certainly a good one that would reduce the carbon footprint of an industry with very large feet (the US Department of Defense has the largest carbon footprint of any government body in the world). But it is still a very small move.