“Each year our use of additive manufacturing has increased, most notably tooling for composites and flight parts.”
~Dan Campbell, Program Manager and Group Lead for additive manufacturing research, Aurora Flight Sciences
Aurora Flight Sciences is a leader in the development and manufacture of advanced unmanned systems and aerospace vehicles. With 500 employees and four US-based locations, they are not your typical aerospace company. In fact, their relatively small size allows them to quickly adapt to the ever-changing needs of the aerospace and defense industry. Aurora has developed optionally-piloted aircraft (Centaur); record-breaking, ultra-long endurance unmanned aircraft (Orion); numerous small man-portable unmanned aircraft systems (UAS); and large solar aircraft. They were recently awarded the DARPA X-plane contract with their unique and innovative LightningStrike VTOL concept. Aurora’s Aerostructures business sector supplies large, complex composite structures and assemblies to many OEMs including Northrop Grumman (Global Hawk & Triton UAS), Sikorsky (CH-53K, MH-60R, S-92, S-97), Bell (525), and Gulfstream (G500).
One of the reasons Aurora is able to consistently innovate is their adoption of additive manufacturing (AM) into almost every aspect of their business. It’s no secret that the aerospace industry has been using AM technologies such as FDM for decades, but Aurora has been among the AM leaders for far more than mainstream prototyping with applications such as composite tooling, production parts, and even the world’s first jet-powered UAV demonstrator. The benefits were immediately obvious to Aurora as they were able to dramatically reduce their design and development cycle, lead time, and overall cost. In many cases, these parts can be printed in days or even hours and with significant cost reductions compared to traditional manufacturing methods.
In addition to composite tooling and production parts, Aurora Flight Sciences is utilizing FDM in R&D programs to create multifunctional composite structures. Dr. Konstantine Fetfatsidis, Director of Advanced Composites Pursuits/Programs at Aurora, is leading a NASA program that merges FDM with automated fiber placement (AFP). This technology enables self-healing of micro-cracks to help prolong the life of large composite vessels that will ultimately carry humans into deep space. Small continuous thermoplastic (PLA) sacrificial filaments (300 – 400 micron diameter) are printed directly between plies of carbon fiber composite materials laid down by the AFP system. After the resin in the composite gels, a post-cure cycle at a slightly higher temperature causes the PLA (which is coated with a catalyst) to de-polymerize, leaving empty hollow channels embedded in the composite. These channels are filled with a two-part chemistry such that when a micro-crack penetrates the channels, the fluids spill into the crack, mix together, and begin to cure.
The question of where to store the healing agent forced Aurora to investigate 3D printed honeycomb cores that could be tailored in size in size and shape for structural performance, while also acting as a reservoir for storing fluids needed for self-healing and thermal management applications. Ultimately, Aurora has used its AFP system to lay up sandwich composites, employing 3D printed cores and embedded 3D printed features, onto low-cost FDM composite tooling that has also been used for trim and drill operations. Over the next several months, Aurora will be scaling up the evaluation to demonstrate the manufacture of a five-foot diameter dome section that includes a core and lay-up mold 3D printed with Ultem 1010 resin by Stratasys.
Aurora Flight Sciences is a great example of a company that made a strategic decision to embrace additive manufacturing (and particularly FDM) in their day-to-day operations and in doing so has realized numerous benefits. They have also positioned themselves to lead in the future through their continued focus on innovative R&D projects that push the boundaries of the technology and lead the way for the implementation of new advancements. Additive manufacturing continues to demonstrate significant value and innovation-enabling capabilities across manufacturing industries, particularly with its ability to disrupt and enhance the fabrication of complex composites structures. As materials and capabilities continue to advance, so will adoption across aerospace, automotive, and other demanding manufacturing industries. For more information on FDM for composite fabrication, visit our composite tooling page at Stratasys.com.