From early development to advanced applications, one industry has been pushing advancements in additive manufacturing (3D printing) from the beginning. The aerospace industry utilizes additive manufacturing (AM) across the spectrum of product development, from concept visualization to testing and final production.
Aircraft companies were early adopters of laser sintering, one of the first commercialized thermoplastic 3D printing technologies, and Direct Metal Laser Melting (DMLM), the first commercially available system for additive manufacturing of metal parts in 2002. Since then, additive metal systems have evolved to expand application possibilities and better accuracy and repeatability, leading to further use by aerospace companies.
During my time at Stratasys Direct Manufacturing, I’ve seen a lot of interest in metal AM from companies not only in aircraft development but also in the private and public space sectors. The rapid adoption from these companies has led to 3D printed fuel injector nozzles, combustion liners, shrouded impellers, and many other applications I address below.
Why aerospace companies use metal AM
The reasons for early adoption are linked to the benefits for lift-off, flight, traveler comfort, and the harsh environments involved in aircraft functionality. Additive manufacturing offers functional components from complex and aerodynamic design geometries that can’t be manufactured with other methods. Functional components with complex geometries and defined aerodynamic properties can be manufactured quickly and cost-effectively. Material and weight savings lower fuel consumption and CO2 emissions. Manufacturer-specific adaptions and small production runs are further arguments in favor of AM technology.
Additive manufacturing is considered a more streamlined manufacturing process than traditional metal manufacturing with no tooling costs and minimal setup. The costs associated with production are incurred for the parts themselves, no matter how small the batch. Design changes to the components can be implemented easily by printing one-off without incurring re-tooling costs and lead times. Aerospace companies can redesign, print, and install parts in their aircraft within days, saving time and money.
Because 3D printing builds components one layer at a time, designers can create complex geometries not possible with traditional manufacturing. Aerospace engineers take advantage of the design freedom to reimagine multiple parts as one contiguous design. Consolidating multi-component designs and utilizing high-strength superalloy metals resulting in a 60% weight reduction over their machined counterparts – a significant flight and cost-benefit when considering fuel consumption.
Current improvements and where we’re heading
The adoption of metal 3D printing has naturally aligned with technology improvements and material availability.
The current list of metals available for additive manufacturing includes tool steels, stainless steels, titanium alloys, aluminum alloys, nickel-based superalloys, cobalt-chromium alloys, and copper alloys.
Material development often results from collaborations between material suppliers, AM system manufacturers, and/ or project customers. For example, Stratasys Direct Manufacturing worked with aerospace companies to characterize Copper C18150 (CuCr1Zr) on Direct Metal Laser Melting (DMLM) systems for thermal control applications in aerospace.
With more collaborations on the horizon to fill in gaps for applications, it’s likely that further material development will increase the niche use of AM parts in aircraft.
DMLM system improvements have varied from technology type to technology type, but most address five key challenges the processes have faced. Compared to traditional metal manufacturing methods like machining and casting, metal additive manufacturing has struggled with dimensional accuracy, material recyclability, isotropic characteristics, stress-induced deformations, and overall build size limitations.
Dimensional accuracy concerns have arrived from the inherent nature of additive manufacturing; factors related to the part geometry, material composition, machine and build chamber atmospheres, laser power, scan speeds, and build orientations all can influence a build.
To combat this issue, users depend on thoroughly vetted design parameters and well-planned part orientation to achieve accuracy. Some system manufacturers such as VELO3D have developed their systems to address issues like to build pauses, inconsistent mechanical properties, labor-intensive quality controls, and decreased use of supports—all while avoiding deformation.
Additional advancements in 3D metal manufacturing enable more design freedom, including the production of low-angle geometries and few or no support structures. The goal is to broaden the capabilities of additive metals technology as well as the economic viability of the process at higher quantities.
"The adoption of metal 3D printing has naturally aligned with technology improvements and material availability"
Where we’re heading
With further material and technology advancements, metal additive manufacturing will open more possibilities for advanced aerospace production and aircraft maintenance activities. Some of the biggest players in aerospace are using DMLM technology for revolutionary designs and advanced production components to help propel their industry forward. Materials development is expected to become an even bigger part of the conversation. The lack of materials diversity - and more importantly, published characterization for additive manufacturing - will inhibit widespread adoption.
Regardless of the challenges, the benefits of additive metal printing far outpace the concerns, and the possibilities are wide open.