2023 has been a pivotal year in the rise of additive manufacturing (AM) in the aerospace industry. In March, the first fully 3D printed rocket, launched by California-based Relativity Space, took to the sky over Florida, and in June, Edinburgh-based aerospace start-up Skyrora revealed the latest testing of its 70kN 3D-printed rocket engine.
Aerospace was an early adopter of AM, and these latest advancements showcase the extent of its capabilities as well as some of the unique benefits that the process offers to aerospace design and production. Yet, several challenges must be addressed for AM to become a true contender to standard manufacturing processes.
With the turbulent landscape facing today’s aviation industry – including sustainability demands, skills shortages, and economic uncertainty – and the next generation of commercial aircraft designs on the horizon, this marks a real opportunity. At Hexagon we see broad potential for AM to future-proof aerospace design, engineering and production, provided manufacturers are proactive and committed to change.
3D-printing’s current role
Today, AM technology is predominantly used to make non-critical parts that don’t bear structural loads: interior features such as armrests, cup holders and airducts. It is also attractive for the manufacturing and repair of ground support tooling and aircraft parts, thanks to its reverse engineering and batch-of-one potential.
But why is AM being limited to relatively non-critical roles? The answer comes down to regulation and cost – aerospace regulations some of the strictest in manufacturing, requiring lengthy approval processes. This makes pushing for wider adoption of AM seem counter-productive for manufacturers, who have established workflows full of certified parts and methods.
Despite slow adoption, the design of commercial airplanes is cyclical. New models and ideas surface over a scale of decades, offering a clean slate for balancing AM benefits with certification constraints.
New aircraft models could also help ease the financial cost of implementation, as established processes can pivot to AM. New aircraft and their optimised designs create opportunities for a step-change in aircraft design, engineering and manufacturing. The recent 3D-printed rocket launch highlights how far AM technology has come, and the ability of some printed materials to handle extreme stresses.
Achieving this step-change will also require incorporating new methods and technologies into the aerospace manufacturing workflow, such as introducing digital twin capabilities earlier in product development. These will need to go beyond established structural CAE simulations to model material behaviours and how the additive technology used can affect the performance of the 3D-printed part. This information can then be made available for system optimisation, where simulations are validated with conventional and non-destructive testing to increase confidence in final part quality and performance.
It can take a lot of people to make a single part, so it’s also essential these digital twin insights are accessible to teams through platforms that facilitate real-time collaboration and feedback between those team members. This would not only allow the industry to take full advantage of AM, but also help to tackle other key issues for the industry, including production skills shortages and productivity bottlenecks.
AM’s unique benefits
Shifting to AM offers aerospace manufacturers several key benefits. Firstly, scalability: AM simplifies the process compared to conventional methods. It relies on software to 3D print models using fully automated and digitally enabled machines, reducing manual labour and expensive tooling.
This digital nature grants AM exceptional agility and flexibility. Fleets of printers can be deployed to scale up more flexible production, as announced at orthopaedics manufacturer Styker’s Cork facility. With the need to double aircraft production in the next 20 years, AM could be crucial in achieving that scale of production due to its versatility in various product lifecycle roles, optimising financial and efficacy outcomes. Secondly, scaling up AM offers significant sustainability benefits to the aerospace industry. Lightweighting of aircraft is key in reducing fuel consumption per flight – this saving compounds significantly across a plane's 25–30-year lifespan. According to BDL’s climate protection report, reducing the weight of a plane by just one kilogram will be enough to reduce its carbon dioxide emissions by 25 tons across its lifetime.
AM also minimises waste, improving ‘buy-to-fly’ ratios – the ratio of raw materials used in the manufacturing process to that which ends up in the air. Aerospace, dominated by subtractive methods like milling, can benefit from AM's reduced material waste. As sustainability rises up the agenda, ‘buy-to-fly’ is an important metric to consider in strategic planning.
AM could also help address the aerospace industry's skills gap. As machine shops and manufacturers struggle to backfill and retrain the current generation of engineers that are highly skilled in traditional processes, the new generation, proficient in digital technologies, are both keen to use new manufacturing processes like AM, and well suited to help contribute to its development within the industry.
What does the future hold?
Today, adoption of AM is sporadic despite the clear business case, restricting the industry from taking full advantage of its benefits. Rather than being seen as a direct competitor to conventional subtractive methods, AM is of most value as a complementary method. If the aerospace industry builds trust in digital engineering processes, then it can integrate AM into more manufacturing processes to leverage its unique benefits for lightweighting, agility and automation and solve some of its most pressing challenges.
Aziz Tahiri, VP Global Aerospace & Defence, Hexagon Manufacturing Intelligence