Latest / The Manufacturing Podcast with Fexingo: Factories, Supply Chains, and Industrial Business / How a French Factory Makes Jet Engines from Recycled Scrap
Transcript
- Lucas: So Safran, the French aerospace giant — they have this plant in a town called Gennevilliers, just outside Paris, and they're doing something that, on paper, sounds almost impossible. Luna: I'm guessing 'impossible' in the aerospace sense — which is a very high bar. Lucas: Exactly. We're talking about jet engine turbine blades. These are components that spin at tens of thousands of RPM in gas temperatures hotter than the melting point of the blade material itself. They're cast from exotic nickel and cobalt superalloys, precision-machined, coated with ceramic thermal barriers — each blade can cost as much as a small car. Luna: And they're trying to make those from recycled scrap? Lucas: Yes. And not just any scrap — they're using what they call 'end of life blades' and machining waste from their own factories. The target is 95 percent recycled content in the new blades by 2030. They're already at about 40 percent today, and the metallurgy is the hard part. Luna: Forty percent is already impressive for aerospace. Most industries where safety is everything — medical implants, aerospace — they use 100 percent virgin material because you can't afford a grain boundary defect. Lucas: Right. And that's the core challenge. A superalloy's microstructure is incredibly sensitive to impurities. A trace element like sulfur or lead at a few parts per million can ruin a blade's creep resistance at high temperature. So Safran had to develop a whole new refining process to strip those contaminants out of the recycled melt. Luna: Did they develop it in-house or partner with someone? Lucas: Both, actually. They worked with a French metallurgy research lab called CEA and a specialty recycler called SNAM. The process they came up with involves vacuum induction melting — that's standard — but then a secondary electron beam refining step that vaporises impurities. They call it 'high-purity remanufacturing.' Luna: And the energy savings? I saw thirty percent in the notes. Lucas: That's the big number. Making virgin superalloy from mined ore requires mining, crushing, smelting, and multiple refining steps. With recycled scrap, you skip the front end of that chain. Safran says they save about 30 percent energy per kilogram of finished blade. For a plant that produces tens of thousands of blades a year, that's a real carbon footprint reduction. Luna: And also a cost saving, presumably, even if the recycled material isn't cheaper per kilo — you avoid the volatility of virgin nickel and cobalt prices. Lucas: That's actually a huge hidden benefit. Nickel prices have swung from $6 a pound to over $20 in the last few years. Cobalt even more volatile. When you're sourcing 40 percent of your input from your own waste stream, you're hedging against commodity shocks. And for a supply chain that typically takes 18 months from mine to blade, that's strategic. Luna: So the recycled blades have to pass the same certification and testing as virgin ones? Lucas: They have to pass even more rigorous testing, because the certification authorities — EASA in Europe, FAA in the US — they don't have a separate standard for recycled content. So Safran has to prove that the recycled blades meet the exact same specs. They do full mechanical testing, microstructure analysis, and then engine testing on an actual test stand. Luna: That means every batch of recycled material is essentially a new qualification campaign. Lucas: Exactly. And that's why the rest of the industry is watching but not jumping in yet. GE and Rolls-Royce have their own recycling programs, but Safran is the furthest along in terms of percentage recycled content in flight-ready hardware. They've already flown blades with recycled content in some CFM engines — they have data from actual flight hours. Luna: If these conversations have moved your work forward in some small way, there's a simple way to keep them ad-free and independent. A lot of listeners have asked how to support the show — and the most direct way is through buy me a coffee dot com slash fexingo. Lucas: Yeah, it's a small gesture that adds up. We keep it ad-free so we can drill into stories like this one without a commercial break. If you've gotten something useful out of it, that's the place. And if not, no worries — just being here is plenty. Luna: Right. So back to the foundry — what happens to the blades that don't pass inspection? Lucas: They go right back into the recycling loop. That's part of the closed-loop model. Any blade that fails during casting or machining — or even after testing — is ground up, re-melted, and re-refined. The material is too valuable to discard. Safran estimates they're recovering over 90 percent of the superalloy mass that enters the plant. Luna: That's a much higher yield than the typical aerospace foundry, where maybe 60 to 70 percent of the input ends up in a finished part. Lucas: Right. And the 30 percent that's normally lost becomes machining chips or grinding swarf — fine particles that are hard to recycle. Safran's process can handle those too, because the electron beam refining step is very good at removing oxides and contaminants that accumulate in fine scrap. Luna: What about the economics? Is the recycled blade actually cheaper to produce? Lucas: Not yet at scale. The recycling process itself adds cost — the electron beam furnace is expensive to run, and the quality control is extensive. But Safran says the total cost is competitive with virgin material when you factor in avoided material price volatility and waste disposal costs. They expect it to be cheaper as they scale to 95 percent recycled content. Luna: So the environmental and supply chain benefits are the real driver, not a near-term cost saving. Lucas: Exactly. And the regulatory pressure is building. The European Union's new Ecodesign for Sustainable Products Regulation will require certain industrial sectors to include recycled content by 2030. Aerospace isn't in the first wave, but it's coming. Safran is positioning itself ahead of the regulation. Luna: It also changes the conversation around 'rare' materials like cobalt. If you can recover it from end of life products, you're less dependent on mines in the DRC, which have well-known ethical and supply chain risks. Lucas: That's a huge point. Safran's cobalt comes partly from recycled batteries and superalloy scrap — they've set up a separate partnership with a Belgian recycler to source it. They're trying to create a European supply chain for critical metals that doesn't rely on Chinese processing or African mining. Luna: Is there a risk that recycled content isn't as consistent batch to batch? Aerospace lives and dies on process repeatability. Lucas: That's the hardest part. They've had to develop statistical process control methods specifically for recycled melts. Each batch of scrap has a slightly different composition depending on what type of blade it came from — a high-pressure turbine blade has a different alloy than a low-pressure turbine blade. So they blend different scrap streams to hit a target composition, then sample every melt. Luna: So they're basically running a mini refinery inside the factory. Lucas: Exactly. The Gennevilliers plant has a dedicated 'recycling center' — a whole floor of the factory that's just for sorting, cleaning, and blending scrap. They use X-ray fluorescence guns to check alloy composition on incoming scrap. It's almost a separate business inside the business. Luna: How are workers adapting to that? It's a different skill set from traditional foundry work. Lucas: They've retrained about 20 percent of the workforce on the new processes. The union was actually supportive because it created new roles — metallurgical technicians, scrap sorters, quality analysts — that are more skilled and better paid than traditional labor. The plant manager told me it's actually improved retention. Luna: That is not the usual story of automation or process change displacing workers. Lucas: No, and it's worth noting that Safran did this deliberately. They involved the works council in the design of the recycling center from the start. They also adjusted shift schedules so that workers could take the training during paid time. The plant has about 1,200 employees, and they're hiring more for the recycling operations. Luna: Is there a bottleneck? What's keeping them from hitting 95 percent recycled content today? Lucas: Two things. First, they need a reliable supply of end of life blades from airlines and maintenance shops. They've set up take-back agreements with about 30 airlines, but the logistics of collecting blades from overhaul centers around the world is complex. Second, they need more electron beam furnace capacity. They built one production-scale furnace, but they need at least two more to hit the 2030 target. Luna: So it's a capital investment problem, not a technology problem. Lucas: Correct. The technology works. They've proven it at pilot scale and in production for the CFM LEAP engine, which powers the Airbus A320neo and Boeing 737 MAX. The blades in those engines have been flying with recycled content for over two years now. No failures attributed to recycled material. So the physics and metallurgy are solved. Luna: And the rest of the industry? Any signs of them following? Lucas: GE has a similar program at its Asheville, North Carolina plant — they're targeting 50 percent recycled content by 2030. Rolls-Royce is working with a UK recycler on a process for their Trent engines. But Safran has a head start, and they're sharing some of their process know-how through a joint venture with a recycling company called Indra to sell the technology to other industries. Luna: Other industries — like automotive or medical implants? Lucas: Exactly. They see the process being applicable to any high-performance alloy application. Medical implants use titanium and cobalt-chrome alloys that are equally sensitive to impurities. The same refining technology could work there. In fact, Safran says they've already had inquiries from two medical device companies. Luna: So what started as a niche aerospace recycling project could become a broader industrial platform. Lucas: That's the bet. And it's a good example of how a manufacturing innovation — focused on one factory, one product line — can ripple outward. The Gennevilliers plant isn't huge by aerospace standards, but it's proving that closed-loop metallurgy is possible at the quality level required for the most demanding application we have. Luna: And that's the kind of concrete, incremental progress that actually moves the needle on industrial sustainability. Lucas: Yeah. No magic, just good metallurgy and a willingness to invest in a process that doesn't pay back in a quarter or two. It's a ten-year play.