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Glenn Takes a Bow for Impact on GEnx Engine

Dr. Whitlow accepts plaque from Glenn contributors to GEnx engine. C-2008_00709.Center Director Dr. Woodrow Whitlow Jr. accepts a plaque recognizing Glenn contributions to GEnx. Team representatives, pictured, left to right, are Dr. Lerch, Dr. Nathal, Hopkins and Dr. Roberts with Dr. Seng looking on. Credit: NASA/Michele Murphy, (WYLE) General Electric (GE) Aircraft Engines' General Manager Robert Schafrik, in Evendale, Ohio, recently presented a plaque to Glenn representatives on behalf of the center's significant contributions to materials technologies introduced in the new GEnx engine. The plaque was given during a ceremony celebrating the GEnx achieving Federal Aviation Administration airworthiness certification. The new GEnx engine is slated to power the Boeing's new 787 Dreamliner in 2009.

"While the GEnx represents a new design, it incorporates years of investment in technological advancements that make it more cost effective and environmentally friendly," said Dr. Gary Seng, chief of Glenn's Structures and Materials Division. "This is a well-deserved bow for the Glenn team members who have worked very hard to earn such distinction."

Glenn contributions to the most significant new materials technologies introduced in the GEnx engine include the following:

Composite Fan Case
As the world's only jet engine with an all-composite fan case (both the front fan case and fan blades made of carbon fiber composites), the GEnx will be lighter, have greater durability and operate at a lower cost. Earlier investigation of lightweight carbon fiber/polymer matrix composite materials, fiber architectures and design concepts were initiated in the 1990s under NASA's Ultrasafe Project of the Propulsion & Power Base R&T Program. The team of Dr. Gary Roberts, Dale Hopkins, Dr. Michael Pereira, Duane Revilock, Cheryl Bowman, Susan Johnson and Dr. Robert Goldberg aided in identifying a promising approach for developing the all-composite fan case. This approach was further developed and optimized in partnership with engineers at GE and A&P Technology, experts in the braiding of carbon fibers, and facilitated through a series of Small Business Innovation Research (SBIR) Contracts.

GEnx engine.GEnx engine.
Credit: General Electric Company
Titanium Aluminide (TiAl) Low-Pressure Turbine Blades
Dramatic weight savings--up to 40 percent--can be achieved by utilizing TiAl low-pressure turbine (LPT) blades, due to TiAl's low density and high-temperature properties. The team of Susan Draper, Dr. Michael Periera, Dr. Brad Lerch and Dr. Michael Nathal designed a laboratory impact test to simulate potential blade damage resulting from the engine ingesting foreign objects. This ground breaking research, which originated under NASA's High Temperature Engine Materials Technology Project (HITEMP) in the Propulsion & Power Base R&T Program, showed that despite limited ductility, TiAL alloys can withstand a relatively large impact without failing catastrophically. This data eventually was used in the design of the GEnx LPT blade, particularly the thickness of the leading edge.

Nickel Aluminide (NiAl) Bond Coat for High-Pressure Turbine Blades
Based on data accumulated from GE and Glenn's longstanding collaboration to quantify the use of NiAl-base alloys as structural blade alloys, the team of Dr. Ronald Noebe, Dr. Robert Miller, Anita Garg and Ivan Locci (UNT) switched strategy to examine its use as a bond coat for high-pressure turbine blades. Bond coat alloys based on both the prior structural alloys and new customized alloys were tested under NASA's HITEMP program. As a result, numerous new patents, including a joint GE/NASA patent, were awarded, introduced and culminated in the new coating used in the GEnx.

ME3 Turbine Disk
Turbine disks are critical to engine performance, efficiency and safety. The ME3 Turbine Disk alloy, developed by a Glenn/GE/Pratt & Whitney team, was initiated in 1993 under the High Speed Research/Enabling Propulsion Materials project and later refined in the Ultra Efficient Engine Technology Program. Dr. Timothy Gabb, Jack Telesman, Dr. John Gayda, Peter Kantzos (OAI), Anita Garg, Dr. David Ellis and Robert Draper were key team members involved in the development of the new turbine disk alloy ME3, which can withstand sustained temperatures of 1300 degree F. This is approximately a 100 degree F increase over disks currently in operation. Although, first applied in the 2007 GE/PW Engine Alliance GP7200 engine, the ME3 is still a noteworthy contributor to the GEnx performance.

"The GEnx is a wonderful example of how SBIR technology can augment research in support of NASA, while providing opportunities to small companies, and, in this case, economic growth to the state of Ohio," said Kathy Needham, chief of Glenn's Technology Transfer & Partnerships Office. "GE's recognition provides an important record of Glenn's continued impact on commercial aviation."

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By Dr. Michael Nathal, Advanced Metallics Branch
with S. Jenise Veris, SGT, Inc.
Assistant Editor