Since before GE Aviation introduced the carbon fiber composite-intensive GEnx engine for the Boeing 787 Dreamliner, manufacturers of the jet engines used on commercial aircraft have toyed with the idea of integrating ceramic-matrix composites (CMCs) into the hot zones of jet engines to reduce weight.
CMCs were held back for some time by lengthy cycle times, high cost and feasibility issues, but in the past year the landscape shifted considerably for two reasons: First, in May, engine maker Rolls-Royce acquired CMC manufacturer Hyper-Therm HTC, signaling its intent to put the material to use in its engines. Then, in June, GE Aviation announced it would build a new plant in Asheville, N.C. for the manufacture of CMC jet engine parts. Both actions signaled serious and substantial commitment of capital to development and commercial application of a material whose time, apparently, has come.
The story behind this shift is explored in depth this month in the feature article "Ceramic-matrix composites heat up" (click on the title under "Editor's Picks," at top right). Author Karen Wood reveals just how seriously CMCs are being assessed, and where and how they’ll be used in next-generation jet engines.
You’ll also notice, in the article, that a third player in the commercial jet engine market, Pratt & Whitney, reports that it has decided, at least for now, against use of CMCs due to concerns about the “maturity” of the material. When you read this, you might wonder, as I did, about how to make sense of these decisions.
Rolls-Royce, GE Aviation and Pratt & Whitney are multi-billion dollar companies. Each has manufactured quality jet engines for decades. Each employs engineers and material scientists who must have approximately equivalent knowledge and abilities. Each makes business decisions based on careful cost/benefit analysis and prospects for long-term success. So, how is it that Pratt & Whitney deems CMCs a nonstarter, while GE Aviation and Rolls-Royce see the material as a major ingredient of their future engine designs?
It may be that Pratt & Whitney’s corporate culture is more risk averse, and perhaps that is the sum total what separates two yes votes from a no vote, here. But I see an additional factor at work: Early adopters become early adapters.
Clearly, GE Aviation and Rolls-Royce see in CMCs real potential for lightweighting their engines. But that does not make them any less interested than Pratt & Whitney in avoiding risk. GE and Rolls-Royce have risked plenty, buying a company and opening a new plant, respectively. But I argue that once a company makes such a decision, the same desire to avoid risk makes these early adopters into energetic and creative adapters. Rolls-Royce and GE Aviation understand clearly that applying CMCs to engines is not a slam dunk. If it were easy, it would have been done already.
With each investment, then, comes a powerful incentive to make that investment pay off. The decision to adopt a new material makes the organization an eager innovator, willing to be more aggressive and think outside the proverbial box — from the lab table to the shop floor — to make the risk worth the taking. When a company invests heavily in a new technology, employees take notice. They see that their employer is venturing into new territory, and they want to make that venture successful. And they want to be a part of that success.
Lightweight, hard and stable at high temperatures, CMCs are emerging from two decades of s...