The adoption of additive manufacturing in aeronautics, though still largely unexplored, offers several advantages. An Italian-led European project aims to combine composite and 3D-printed materials to create next-generation aircraft that are lighter and more sustainable, while also establishing a complete supply chain for parts reuse.
How should future aircraft be conceived? They must be safe, high-performing, and undoubtedly more sustainable. In this context, the use of advanced technologies, such as additive manufacturing in aeronautics, can contribute to creating lighter and stronger structures, thereby reducing fuel consumption and emissions.
Air transport generates between 2% and 3% of global CO2 emissions, and its overall climate impact is at least twice that associated with carbon dioxide alone, according to the EU Directive 2023/958. Within the transport sector, aeronautics is the second most significant contributor to climate impact, after road transport.
Sustainability, which includes the need to reduce emissions, also involves different production methods aimed at reducing the use of raw materials by utilising and reusing existing ones. All these complex needs are at the heart of ongoing research efforts.
To this end, a European project has been launched to develop new techniques for integrating carbon fibre composites and metallic materials produced via additive manufacturing. Called MIMOSA, and coordinated by the Polytechnic University of Turin, it includes six industrial partners and two research centres.
Its objectives are twofold: technologically, it aims to develop new techniques for combining different materials. From a production and management perspective, it seeks to lay the foundations for a comprehensive design and manufacturing supply chain, capable of integrating all aspects necessary to produce more sustainable aircraft, from design to end-of-life.
The production cycle also includes the regeneration of raw materials for reuse at the end of service life, by adopting innovative technologies.
TAKEAWAYS
The benefits of using additive manufacturing in aeronautics
There are numerous advantages offered by the use of additive manufacturing in aeronautics. In the article “Additive manufacturing in the aerospace and automotive industries: Recent trends and role in achieving sustainable development goals,” a team of researchers from the Sustainable Energy & Power Systems Research Centre at the University of Sharjah (UAE) highlighted the benefits of 3D printing in the automotive and aeronautics industries.
In terms of reductions in CO2 emissions and energy consumption, the estimated benefits range from 38% to 75%. Additive manufacturing enables a reduction in material usage and waste. Its adoption is also promising for designing aircraft with performance that surpasses traditional models.
An exemplary case is the study by the Air Force Research Laboratory on the design, printing, construction, and launch of the first single-piece rocket engine thrust chamber produced additively.
Among the major aeronautics manufacturers, the American company Boeing has long utilised this technology. For its 777X airliner, it has chosen the GE9X, the largest and most powerful jet engine on the commercial aeronautics market, which contains more than 300 metal parts produced through additive manufacturing [source: GE Aerospace].
The European multinational Airbus also employs additive manufacturing in aeronautics to produce parts for aircraft and helicopters. Moreover, it developed the world’s first metal 3D printer for space, created for the European Space Agency.
Lockheed Martin has long collaborated with Sintavia, a specialist in additive design and the production of advanced components for aeronautics and defence applications, to expand research on metal additive manufacturing.
The Brazilian company Embraer produces several parts of its flagship aircraft fleet using 3D printing due to its advantages. Through additive manufacturing in aeronautics, the company has reported that many parts of the E-Jet E2 family now weigh up to 40% less.
The aviation sector in Europe and the MIMOSA Project
The European Union has long aimed to reduce emissions across various sectors to achieve its Net Zero target by 2050. Through the recently updated EU Directive 2023/958, it has revised the Emission Trading System (ETS) regulations for air transport.
This decision is significant given the civil aeronautics sector’s importance within the EU, both in terms of employment – accounting for 405,000 jobs – and economically, with revenues of €130 billion and a key role in exports valued at €109 billion. Additionally, the sector is a crucial contributor to research and development, with R&D expenditure by industry and governments estimated at €8 billion in 2019 [source: European Commission].
Among the dedicated research programmes is the European project MIMOSA (Multimaterial Airframes based on 3D Joints between AM Metals and Carbon-Fibre Composites). Launched in 2022 and set to conclude in 2025, it is coordinated by the Polytechnic University of Turin and benefits from nearly €5.5 million in EU funding. The project aims to develop new techniques for integrating carbon fibre composites and metals manufactured through additive processes in aviation.
Additive manufacturing in aeronautics: innovative technological elements
According to Professor Giorgio De Pasquale, coordinator of the project and head of the Smart Structures and Systems Lab at the Department of Mechanical and Aerospace Engineering (DIMEAS) at the Polytechnic University of Turin, the project is poised to effectively support future developments in the aeronautics sector.
In particular, it is promising for hybrid propulsion aircraft (electric and hydrogen), which require lighter structures with equivalent strength to offset the extra weight of tanks and batteries.
Additive manufacturing in aeronautics is being explored in the MIMOSA project: «The combined use of composite materials and 3D-printed metals is a novelty we are working on. It has not yet been adopted at the production level due to stringent regulatory constraints that detail the adoption of this technological solution in aviation. Our first innovation aims to address the regulatory aspect: we plan to develop guidelines for the validation, qualification, and certification of this technology».
Technically, the project’s partners have devised a joint entirely different from traditional ones, which rely on riveting or, in the case of small or ultralight aircraft, bonding. «In the case of MIMOSA, these are replaced by co-moulding between the metal and composite parts, properly connected», explains De Pasquale.
During the project, a prototype of a strategic component – the vertical tail stabiliser of a passenger aircraft – will be produced using this joint technique for the first time. «This will be done in full compliance with aviation homologation and certification guidelines, using materials already qualified for the sector».
This structural component is particularly interesting as it is traditionally attached with numerous rivets that can be eliminated thanks to the technology developed by the project team.
Use and reuse: the circular future of aircraft and components
The sustainability aspect is repeatedly emphasised in the project coordinated by the Polytechnic University of Turin. The plan includes the recycling of aircraft structures even at the design stage.
«It’s more accurate to talk about material regeneration. After separating the composite from the metal at the end of service, they will be directed into two parallel lines. For the composite, it will undergo traditional recycling, which involves creating parts that become additives for new polymer components. The more innovative part, however, concerns the metal. The scrap is subjected to atomisation, a process that generates metal powder from the scrap, which can then be used as secondary raw material in 3D printing, thereby re-entering the production cycle».
There is an additional impact on sustainability concerning the rethinking of the supply chain with this joint approach. Currently, aeronautical structures are made from different materials on separate production lines (composite and metal laminate) and supply chains.
This results in the movement of parts and the consequent need for transportation, energy consumption, and emissions. Conversely, when combined, as in the case of MIMOSA technology, consumption and emissions are drastically reduced.
Glimpses of Futures
The potential for additive manufacturing in aeronautics is significant, but there are still aspects that need improvement and further exploration to ensure its widespread development.
To anticipate possible future scenarios, let us now outline – using the STEPS matrix – the impacts that adopting this technology for the design and production of future aircraft might have on various fronts.
S – SOCIAL: the gradual adoption of additive manufacturing will create new job opportunities, particularly for specialists in 3D printing technologies, design, engineering, and maintenance. For instance, in March, the US company GE Aerospace, a leading global manufacturer of aircraft engines, announced plans to invest $650 million this year to enhance production facilities and the supply chain, with $150 million earmarked for 3D production. This technological investment is accompanied by the need to hire over a thousand new employees. Another potential social benefit is the decentralised production enabled by 3D printing, which can boost local economies and SMEs, allowing them to participate in the aeronautics sector. Furthermore, it supports the development of innovative new enterprises, such as dedicated startups.
T – TECHNOLOGICAL: additive manufacturing is a relatively young technology of significant interest for research and innovation. According to a report published by the European Patent Office last September, inventions in 3D printing surged between 2013 and 2020. International patent families in 3D printing technologies grew at an average annual rate of 26.3%, a rate «almost eight times faster than all technological fields combined over the same period» [source: EPO].
E – ECONOMIC: the global market for additive manufacturing in the aeronautics (including aeronautical) and defence sectors, valued at $3.58 billion in 2020, is projected to reach $13 billion by 2028 [source: Fortune Business Insight]. The positive economic impacts can also be measured in terms of reduced lead times, increased production efficiency, and fuel savings.
P – POLITICAL: the European Union regards additive manufacturing as the driving force behind the EU’s industrial evolution. Consequently, one of the task forces comprising the Industrial Forum, which is an integral part of the European industrial strategy initiated in 2020, has collaborated with external stakeholders to provide advice on the adoption of AM technologies and processes by European industry. The task force published its report in 2023, offering recommendations to the European Commission to accelerate the adoption of advanced manufacturing technologies, while highlighting the benefits of additive manufacturing and clean technology for decarbonising the European economy [source: European Commission]. In the USA, President Biden launched the Additive Manufacturing Forward (AM Forward) initiative in 2022, alongside five national manufacturers. This voluntary agreement between the government and large manufacturers aims to help smaller American suppliers increase their use of additive manufacturing. This programme led to the approval this year by the US Small Business Administrator and the commencement of private capital collection for a dedicated SBIC (Small Business Investment Company) fund for Forward Manufacturing (AM) Additive Manufacturing. SBIC funds manage over $42 billion in private and SBA-backed capital, providing equity investments and long-term loans to small businesses across various sectors [source: White House].
S – SUSTAINABILITY: the environmental impact of adopting additive manufacturing is significant. In the aforementioned case of Embraer, the use of thermoplastic AM replaced manual and mechanical processes for making parts and components, cutting production time by 50% and reducing waste by 65%, thus avoiding employee exposure to volatile organic compounds. It is estimated that, compared to traditional manufacturing processes, additive manufacturing could reduce waste and material costs by nearly 90% and energy consumption by 25% [source: Department of Energy].
