Over the past year, the now ubiquitous Zoom window has afforded us a small but tangible snapshot into each other's lives. For Eliana Fu, it’s the glittering Las Vegas sign in the background which signifies a recent move from Los Angeles to join the North American outfit of laser and machine tool manufacturer TRUMPF.
We’re meeting remotely to talk about aerospace and with a wealth of experience from welding at TWI to rockets at SpaceX, Fu has much to draw from. A materials science graduate, Fu was employee number 20 and the first female engineer at Relativity Space, a company that was set up with a grand vision to fully 3D print and launch a rocket. Now, as an Industry Manager within TRUMPF’s laser division, Fu’s work is centred on additive manufacturing (AM) in the aerospace and medical markets.
Here, TCT Head of Content Laura Griffiths speaks to Fu about all things additive and aerospace including supply chain flexibility, new materials and how aerospace is leading the charge for AM innovation elsewhere.
TCT: The last year has stimulated conversations around supply chain and AM’s role within it. Where do you think aerospace can benefit from the flexibility of AM within its supply chain?
EF: We saw immense supply chain woes during the pandemic and then recently, again, during the Suez Canal crisis. I think for the long lead time components or materials which are single source, I'm really surprised if people haven't become more sensitive to the supply chain issues. I think AM can alleviate some of these issues if certain parts, let's say non-fracture critical parts, can be made by 3D printing because it will help take some of the burden off. What we need to always remember is, don't waste time by reinventing the wheel because files exist or don't select the wrong material for medical applications because they can't be autoclaved. A little more coordination and file sharing from that aspect, that also helps alleviate some of that burden.
Eliana Fu, Industry Manager for Aerospace and Medical at TRUMPF.
TCT: Commercial aerospace was heavily affected by the challenges over the last year. From your experience, has that disruption had an impact on the adoption of AM technologies and applications within the sector as it tries to recover? Could it play a role in the recovery?
EF: The industry will come back. Consumer passenger flights will return. I think one of the interesting things is, some of the pain points in the supply chain were actually brought to the forefront and one of the methods to alleviate that was using AM. It's even possible that some parts whose manufacture you couldn’t do traditionally during that time period and was converted to AM, they may never go back.
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TCT: When discussing AM in aerospace, the GE Leap Fuel nozzle is still commonly cited as the most well-known application. While we have of course seen numerous other examples of AM in end-use aerospace parts, does that speak to how challenging it is to get an aerospace part into the air?
EF: We still haven't found that one golden egg type of product that's going to be that game changer. Although hundreds of those parts have been printed, there are still plenty of polymeric parts that have also been printed that are flying today on commercial aircraft. I mean, there almost isn't an aerospace programme that doesn't have something printed.
We still need to evaluate, very carefully, where it makes sense to have a 3D printed part or where it still makes sense to use traditional manufacture. The cost equivalency doesn't always translate one to one because we don't take into account things like downstream post-processing and component testing and integration and all those kinds of things. So that's one of the things that's holding us back.
TCT: Prior to TRUMPF, you were at Relativity Space. Can you talk about your experience there and how you navigated turning traditionally manufactured parts into an AM only product?
EF: I had a great time at Relativity Space. There's a lot of firsts that they created, saying that we'll be the first to fully 3D print and launch a rocket by using additive processes. I think what's different about it is bringing that process in-house, decreasing the lead time, and the unique advantage of AM (which is not just to build unique designs or components) but what it offers is the opportunity to get to space faster. So, it's a customer who would have to wait years or more on any other person's flight if they were going to other space providers you'd be at the bottom of that list! It creates opportunities for other people to get their products into space and that is also true of all the other new space companies. I think it's fantastic. It's opening up the possibility of more spaceflight for more people.
TCT: Can you talk about any key challenges that you think are prohibiting the acceleration of AM in aerospace?
EF: Some parts that you think would be cool to make by AM, you simply can't make them. Feedstock doesn't exist or the size of the machine doesn't work with the component that you want to make so you still cannot print everything that you want to print. In metallics, some materials just don't lend themselves to the AM process because the equivalency would be unweldable so they suffer from cracking. So, working with materials manufacturers to find out what direction new materials designed for AM and what AM processes are the best ones to match with those [materials]. Some of the other things are continuous improvements in the technology. For example, TRUMPF now has 500°C preheating of the larger TruPrint 5000 powder bed machine that will alleviate some of these kinds of problems.
Additive manufacturing developments in copper are opening up more applications. (Source: TRUMPF Group)
TCT: You’ve previously emphasised the importance of creating new materials specifically for AM processes. Can you talk about the progress that is being made there?
EF: The main materials for AM, things like Inconel 718 or Ti-6Al-4V, they come from the wrought product world and they've been with us for like over 60 years. They just happened to be able to be melted and solidified by a laser beam but that doesn't mean that we should be standing still, we should be looking at new materials designed specifically for AM or even consider changing what we know about existing alloys so that they work better with AM. I'm talking about things like high strength aluminium alloys, where the strength comes from lower cost elements that provide the strengthening mechanisms. Using things like copper alloys for rocket engines by laser powder bed printing, that's interesting, things like the GR-Cop 42 alloy. We need to think about making titanium alloys cheaper or more sustainable and then, a huge topic, implications for recycling and reducing the overall carbon footprint of the process.
TCT: At TRUMPF specifically, we’re seeing advancements in green laser technology increasing productivity for certain materials. Are there any opportunities here for aerospace?
EF: You’ve touched on my favourite subject. They're super exciting and they're really suitable for reflective materials like copper, also aluminium and then noble metals like gold, silver, and platinum. So using the shorter wavelength means that more of the laser energy is used and not reflected away. So that results in the higher as-printed density, better surface finish and a nicer product overall. I see green lasers coupled with things like the GR-Cop materials being able to print better products like rocket engine components or even commercially pure copper for electrical thermal conductivity devices, so whether they're heat exchangers or other kinds of thermal devices, having a higher success rate. I'm super pumped for that.
TCT: In a recent Women in 3D Printing panel, you spoke about how aerospace is an industry “sticking its neck out” when it comes to leading the way with AM. Can you elaborate on that and how aerospace might inspire AM adoption in other sectors?
EF: Aerospace and space have always been, I think, where innovations have taken place. Things like Velcro came about as a result of designing products for spaceflight. But in fact, right now, we're seeing other industry sectors that are making innovations and using AM to help them where it makes sense. I would say a big one would be customisation in healthcare and medical, like making a 3D printed custom titanium ribcage or printing dental components and implants. […] I moved to Las Vegas so a few weeks ago, I was able to see the world's biggest 3D printed art sculpture at the Raiders stadium here in Las Vegas and, talking about the home printing hobbyist and craft people, DC Comics released STL files for people to be able to print their favourite characters at home. So, AM is here and it's here to stay.
