Interview first published in the January/February 2022 issue of 3D ADEPT Mag. Roles, equipment and outlook reflect that period.
Aerospace is among the sectors that adopted AM early, for prototyping, tooling and then certain production parts. Design and qualification needs lead manufacturers to examine new production methods.
Major companies such as Lockheed Martin, Airbus, Boeing and Northrop Grumman also rely on partners that can develop and control these processes.
A conversation with Sintavia’s CEO Brian Neff highlights these various directions the commercial aerospace market is embracing as well as the new manufacturing strategies they require.
“Service bureau” can describe very different offerings, specialised or serving multiple industries. In this interview, Sintavia presents itself as a design and production partner primarily focused on aerospace and defence.
With the founder & CEO’s roots in the aerospace industry, roots that include an extensive experience in the MRO and OEM manufacturing fields, it’s easy to understand that Sintavia seized the opportunity to build an offering that is vertically integrated with various demands within the aviation industry. Indeed, AM might be the most highlighted manufacturing process in Sintavia’s production, but to be good at this game, it’s crucial to have a solid understanding of metrology, metallurgy, machining, heat treatments, testing, etc.; in a nutshell, all sub-processes that may help you define a real manufacturing strategy around AM.
Manufacturing strategy
Founded in Florida in 2015, Sintavia developed in a sector that was already using AM. Scaling capacity required investment in equipment, expertise and application qualification.
With about 30 industrial printers in-house at the time of the 2022 interview, including multiple from GE Additive, TRUMPF and, obviously, EOS, including eight M400-4 quad laser printers, Sintavia decided very early to focus on “the very best way to leverage AM”.
Return on investment had to be established for each application while industrial practices and capabilities continued to evolve.
“It can be frustrating, but to get there you have to invest in the void. It can be hard to do for some organizations because it requires a lot of money, time and dedication to see value and that’s a risk many do not want to take. When we first started, we acquired a number of different machines from various OEMs. It is essential to any company diving into this business to understand the technology and that’s what we were trying to do: understand the technology and gain a lot of hands-on experience.
As time has developed, we have been able to identify which areas for which machines are the best. These 3D printers are tools we have to leverage for specific purposes and each of the various 3D printers we acquired brings a unique strength for specific areas. These areas involve for instance, the alloys that we use, the size and dimension of the parts we manufacture, the use cases of the component for manufacturing…for instance, we can meet the needs of those who want tall parts with the AMCM M4K-4 systems, we produce very good Titanium small parts on Arcam machines.
In a nutshell, we try to make sure that we can meet all the different needs of our customers. Once we saw the benefits of printing very complex systems via DfAM, we said we wanted to focus on the hardest geometries possible, and it was a very smart choice. Achieving and focusing on the most complex applications is what enables us to leverage the best of these technologies”, Neff explains.
Laser beam powder bed fusion (PBF-LB) held a central place in Sintavia’s portfolio at the time. The Arcam machines mentioned in the quotation instead use an electron beam.
Powder-Bed Fusion yes, but an eye on other AM processes
Qualification remains specific to the process, machine, material and application. ISO/ASTM 52941:2020, published in November 2020 and reported by 3D ADEPT in January 2021, addressed qualification and requalification of aerospace laser PBF machines. It did not automatically certify parts. That historical reference has since been superseded by the 2026 edition.
Neff describes the advantages he sees for the applications addressed by Sintavia. “The reason comes down to materials properties. In every type of manufacturing, you have to show a level of quality, and this requirement is even more stringent in aerospace manufacturing. On the other hand, it should be noted that the rigours of flying and landing can be hard in this industry because many errors could occur. Powder-bed fusion is a very sturdy type of technology that can deliver strong and durable components. The robustness of the process is demonstrated through lab analysis, microstructures, and mechanical testing. [PBF-LB] enhances a specific part, and we can demonstrate that this 3D printed part is stronger than its counterpart made via traditional manufacturing”, the expert outlines.
As AM processes use to be compared to traditional manufacturing processes, Neff draws attention to the fact that engineers should not compare PBF-LB to freeform welding. “This is not freeform welding. Freeform welding presents some weaknesses that aerospace manufacturing cannot withstand—similar to investment casting which has production variations that aerospace manufacturing does not like. At Sintavia, we use digital molds instead of physical ones and they deliver a totally repeatable process”, he adds.
These comments describe Sintavia’s approach. Casting and welding remain in aerospace use, and a digital file alone does not guarantee repeatability. Performance comparisons require a defined material, final condition and test protocol.
Apart from the potential of PBF-LB, Sintavia’s team will keep an open mind regarding other AM processes that may deliver a significant difference in the manufacturing of aerospace parts. These manufacturing processes include for example, DED for its versatility of use and ability to deliver multi-material parts and WAAM, “which is still very underestimated, yet is interesting for some rocket applications and large structural applications”.
WAAM is a form of directed energy deposition (DED) using wire and an electric arc. Combining materials depends on equipment and metallurgical compatibility.
Investing efforts to develop the right materials parameters for the right processes
Developing a metal application requires connecting powder characteristics with build parameters, post-processing and final properties. Experience with polymers does not transfer automatically to metals. This does not imply that every parts manufacturer must produce its own powder.
In July 2021, Sintavia announced a proprietary process for GRCop-42, a copper alloy developed for demanding applications, including rocket thrust chambers.
The announcement combined EOS M400-4 printing parameters with heat treatment. Sintavia reported a minimum density of 99.94% and minimum elongation of 32.4%, without hot isostatic pressing in that process. The release also cited 28.3 ksi and 52.7 ksi using inconsistent yield and tensile-strength labels. Those two values therefore cannot be used here as correctly identified mechanical properties; the qualification datasheet must govern. Time and cost savings were the company’s reported benefits.
The proprietary printing technology for this material is just one of many examples of properties Sintavia has developed over the years. While Neff clarifies that, they have no intention to become a powders’ producer, the ability to address the reflectivity and high thermal conductivity challenges raised by copper is a milestone the entire team was very proud to achieve.
“You have to develop your own printing parameters if you want to have the best chance to succeed. We have already developed nearly 30 proprietary material parameters. We usually don’t announce each set of parameters we develop for specific powders but copper being a unique material, we were very proud of what we achieved with this material. Other developments (with refractory powders) are in progress and will be announced soon”, the CEO comments.
Current routes the commercial aerospace market is embracing
You’ve certainly heard me say this a lot, and I will reiterate it: investing in materials and processes is good, but these investments might be ineffective if they are not supported by current demands in the market you target. Surprisingly, for an industry that is described as very conservative, the aerospace market is opening up to more ambitious sub-segments that are perhaps worthy of AM’s potential.
“My expertise has always kept me to more traditional aerospace applications. There has been a lot of mini-markets that have been developing lately. Three of them currently stand out from the crowd: private space launches, hypersonic flight and electric commercial flights. When I started the company in 2015, I couldn’t imagine it would explore the path to private launches”, Neff shares.
For Sintavia’s representative, the common thread to these routes is DfAM (Design for Additive Manufacturing). “From a commercial standpoint, the adoption of AM in the commercial space industry urges the commercial aerospace industry to accelerate its adoption of AM – which is great to see. Moreover, there is a freedom of design when you are using AM for complex parts. In each of these paths, aerospace players are given the opportunity to create something new, something they have never done before, and AM is now giving them a myriad of possibilities to explore this potential”, he adds.
The interview emphasises propulsion systems, combustion chambers and regenerative cooling passages. Their geometries can benefit from AM, subject to demonstrating the required performance, manufacturability and qualification.
The path Neff describes illustrates a specialisation strategy: selecting complex applications and developing design, parameters and controls together. Its value must be assessed for the relevant programmes rather than as evidence of AM’s universal superiority.
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