If you want to see the future, drive about an hour northeast of Turin to Cameri, where Avio Aero has a new factory. Here, the engine components maker – a GE Aviation subsidiary since its $4.3 billion acquisition in August 2013 – has focused its additive manufacturing capability. The plant is much like any other greenfield manufacturing site, with its smart glass frontage, car parking, reception, a few offices, loading bay and production floor. Except the production floor is a room barely 20m square with ample natural light and what appear to be eight soft-drink vending machines, in two rows against opposite walls.
A couple of engineers – one from Avio and one visiting from GE’s Upstate New York technology development centre – consider one of the machines.
They aren’t really vending machines, of course. There are no coin slots, and the end product must be cut off a titanium base rather than merely fished out of a drawer. But to anyone who has grown up with massive factories that take in myriad component parts and sub-assemblies and run them all through elaborate machinery at multiple production stations manned by hundreds of workers, these 3D printers are manufacturing from another planet.
Most of the machines at Cameri are electron beam melting (EBM) units, a technology ideally suited to making parts out of hard metals such as titanium. Building a nest of low-pressure turbine blades some 25cm long in layers of about 0.1mm at a time – each layer of metal powder welded to the layer below by a high-energy electron beam – looks almost painfully slow. Except what happens in those Coke-machine-sized cabinets is virtually the entire process, some subsequent surface finishing or polishing aside.
The only raw materials coming in are ingots of various alloys, which Avio atomises in-house to keep total control of the quality of the powder it pours into the EBM machines’ hoppers. Ultimately, says Avio, the process is faster than making the blades by traditional casting.
Just to give engineers who don’t have access to such technology something else to dream about, there are some 150 parameters that determine the machines’ performance, but Avio has identified 35 that are most critical. If any go off kilter during production, the process stops; if some are on the edge of the normal range, a part may be checked; but if all are normal, the part can go straight to finishing and ultimately engine assembly – 100% confidence in every item, with no post-production testing.
For components demanding less extreme materials than titanium alloys, a similar but lower-temperature technology called direct metal laser sintering (DMLS) provides finer surface finishes direct from the printer. In a nice symmetry, Avio’s decade of experience with additive manufacturing is mostly focused on EBM, while GE, which is far enough down the 3D-printing road to be using the technique to make hot-section blades for the new CFM International Leap engines, has put more of its efforts into laser sintering.
There is much more, however, to the GE-Avio tie-up than a convenient division of investment. Giulio Ranzo, Avio Aero’s strategic marketing and product leader, sees in additive manufacturing a technology that has the potential to disrupt the aerospace industry in favour of those who master it early. And, he notes, Avio has been working on the details since 2004, when it acquired a small business called Protocast. By 2007, it had made prototype fuel nozzles for the Eurojet EJ200, which powers Eurofighter Typhoons, and now, in 2014, he sees Avio as having covered a long stretch of the “path to production”.
With the company’s acquisition by GE, he says: “We merged our paths. It acquired a decade of experience, which in this industry is worth something.” After all, he says, anybody can buy a 3D printing machine – but they can’t buy experience in testing, stability and process reliability. Given that the two companies had independently taken complementary technology routes in additive manufacturing, he says, GE Aviation effectively doubled its knowledge of the process with the buyout.
For Avio, however, the impact of the acquisition has been profound. First, the company had to grapple with the challenge of maintaining its position as an important supplier to virtually every engine manufacturer after becoming an integral part of one of their main rivals. Riccardo Procacci, a long-time GE man from the oil and gas and turbomachinery business who has headed Avio Aero since the takeover, told Flightglobal at the Farnborough air show that the past year has been one of building firewalls between Avio’s clients and GE, along with refocusing the Avio product line around transmissions, low-pressure turbines, sand casting and additive manufacturing while adopting GE’s expertise to improve its services offering.
As evidence of success, Ranzo points to the October 2014 agreement with Pratt & Whitney Canada that makes Avio a risk-sharing partner on the engine maker’s PurePower PW800 engines for Gulfstream business jets. Avio will design and supply the accessory gearbox, turbine exhaust case and mixer. Avio’s partnerships beyond GE, he says, are “restored, even expanding”.
What counts, he adds, is to be cost-competitive, to deliver on time, to provide premium quality and to be resilient, able to overcome setbacks. “If we do these four things well, our customers will involve us. We hear this loudly.”
GE, he continues, has a reputation for best practice in the supply chain, and Avio is pushing hard to learn from that experience. Such change is not fast, he says – much of Avio’s work is in big, legacy programmes – but the benefit of joining GE is already showing.
Weekly meetings of GE plant managers are a case in point. As Ranzo notes, when you have one or two factories, you don’t know how well you are doing. But when the data shows you are performing poorly on any measure compared with 100 peers, “you have no place to hide”. He describes this collegial monitoring of performance and practice a “military approach” to management.
One of the issues exercising GE and Avio minds, of course, is how to manage the transition to a next generation of engines and a next generation of technology. As Ranzo sees it, a key to that future will be to make huge gains in weight reduction, performance and cost savings by exploiting 3D printing to its full potential, which means to build the technology into the original design. With additive techniques, it is possible to make shapes that would be difficult or impossible to make by traditional “subtractive” methods. This is why GE is already printing Leap high-pressure blades, which must be hollow to allow for the internal flow of cooling air.
By putting material only where it is needed, radical weight reduction is possible. Ranzo likes the example of an internal contest to cut weight of existing structures; the winner devised a 3D-printed engine bracket that was 84% lighter than a part Avio currently makes. And, an obvious objective is to reduce part counts, further reducing weight, complexity and assembly time.
Avio’s main site at Rivalta di Torino is part of what was once a huge factory complex run by long-time parent Fiat, which has largely abandoned the site – a sign of the decline of what was once an empire that made Turin, effectively, a company town.
Between the headquarters and transmissions factory, the plant is home to 2,000 Avio workers. It is state-of-the-art, designed just a decade ago and capable of being reconfigured or expanded. Special machinery being installed in a stand-alone sector of the plant to satisfy the P&WC deal for PW800 components is described as the most exotic available and probably more automated than anything comparable in aerospace.
Ranzo, meanwhile, reckons that in four or five years’ time a new generation of 3D machines will be available that are big enough to make some large components like engine structures that are currently made by Avio’s sand-casting unit. Perhaps 5% of an engine could be printed by then, he says. “But this technology has significant potential because the field of application is so broad.”
Even if additive manufacturing fulfils its potential, there will still be much to do in Rivalta. But in 20 years, will any plant like this one still exist or will all aerospace look like Cameri? Nobody really knows, of course, but if nothing else it would be a great irony if Turin, whose recent fortunes have been battered by the struggles of an icon of that 20th century industrial symbol, the automobile, should be a birthplace of the disruptive technology of the new century.
Source: FlightGlobal.com
