Additive metal techniques will go far beyond a few specialized uses and disrupt the way aircraft engines and some other aircraft parts are made, says Udo Burggraf, business development manager for GE Additive and its subsidiary Concept Laser.
In a webinar sponsored by Michigan State University’s Department of Mechanical Engineering, Burggraf provided the reasoning behind his expectation that these factors will have powerful knock-on effects on engine and aviation aftermarkets as well.
Focusing on Direct Metal Laser Melting (DMLM), his preferred additive technology, the GE exec argues, “it will change the way engineers design, OEMs makes and shops maintain engines.”
Surveying GE’s use of additive on its LEAP, Advanced CT7 and Advanced Turboprop engines, Burggraf says the new technology already has generated $5 billion in internal cost savings from the ability to produce bigger parts made from better materials and with more efficient systems. Moreover, he emphasizes that GE intends to share about 90% of its additive expertise with the market, retaining only 10% for its internal use.
The LEAP’s fuel nozzle tip is the best-publicized of additive achievements. Twenty parts were transformed into one, costs were reduced 30%, aftermarket inventories are reduced and maintenance decreases with a part that is five times as durable as the former assembly. And weight, which usually increases with better performance, went down 25%. “Complexity is free, you just put materials where needed for load,” Burggraf says.
GE asked its engineers what part of the old CT7 could be produced additively. They estimated about half, and the new A-CT7 reduced the 300 parts in its main frame assembly to one part. For the advanced turboprop engine, testing went down from 12 to six months, weight declined 5%, and 855 parts were replaced by 12 printed additively, all for a 20% reduction in fuel burn.
Additive metal will be crucial in engines, which are almost entirely made of metal. But many other components and complex parts of airframes may also be good candidates for the technique.
In all cases, fewer parts will mean a much simpler supply chain, both in manufacture and in future MRO. “Instead of many component OEMs and MROs, it will need many fewer,” Burggraf says. But these fewer suppliers are likely to be larger and much more sophisticated than the firms they replace.
For one hurdle to exploiting additive potential is that suppliers must be qualified at additive manufacturing to the very high safety standards required by aviation’s safety-critical parts.
There are two paths to qualification.
The first, the point design approach, is economically impractical because it requires the destructive testing of so many parts, up to one in six produced.
The preferred allowable approach to qualification requires much less destructive testing. But it means tier-x suppliers to engine and other aircraft OEMs will have to prove their capabilities in design, materials, additive processes and final production of the part itself. Each of these categories has many sub-elements that must be qualified and monitored to keep regulators and prime OEMs confident that safety standards will be maintained.
GE, which qualified the first additive part for FAA approval, stands ready to help both its own and other aviation suppliers meet these rigorous standards.
Additive will also mean that production of replacement parts is much more aligned with demand, rather than requiring the periodic high-volume runs and large stocks necessitated by traditional manufacturing. Part stocking, distribution, repair and asset management will change drastically for those parts that are made with the new techniques. And it is uncertain whether used parts will still play as important a role in the supply chain.
In any event, Burggraf believes the gains of additive will become even more important as new airframes and engines are designed. His company now works within an 800x400x500mm DMLM cube, but it is developing the capabilities to produce larger parts.
International Aircraft Engine Association initiated the webinar.