GE revamps jet engines with innovative Japanese composites
New material reduces weight and increases heat resistance
TOKYO -- Tough, lightweight silicon carbide fibers will help improve the fuel efficiency of General Electric's aircraft engines and could spread to other uses, following in the footsteps of earlier Japanese innovations in materials engineering.
Japan's materials industry has had success with carbon fibers. Aircraft makers increasingly substitute carbon-fiber-reinforced plastics for aluminum alloys in wings and fuselages. New midsize to large craft built by Europe's Airbus and America's Boeing have airframes composed of more than 50% CFRP.
The International Civil Aviation Organization has called on airlines to cap carbon dioxide emissions on international routes. Such changes add urgency to the pursuit of aircraft fuel efficiency. Coupled with a projected demand for 38,300 passenger aircraft in 2035 -- roughly 80% more than 2015 figure -- Japanese material makers likely will maintain their market dominance.
General Electric uses ceramic composite materials made with silicon carbide fibers in its new GE9X aircraft engines, which will be mounted on next-generation Boeing 777X jets. The engine maker already has received orders for the equivalent of 300 aircraft.
GE is substituting silicon-carbide-fiber composites for nickel alloy in four parts, including turbine blades. Cutting-edge materials and a retooled design gives the GE9X 10% better fuel efficiency than earlier engines.
Ube Industries plans to add a silicon carbide fiber production wing by 2025 at a plant in Ube, Yamaguchi Prefecture. The company currently has only a test plant for the material. It intends to invest tens of billions of yen to lift annual production capacity 20-fold to 200 tons, aiming for 5 billion yen ($43.2 million) a year in sales of the material. Japanese heavy industry group IHI will process the fibers to make composite components.
Nippon Carbon recently upped silicon carbide fiber capacity at a Toyama Prefecture plant by 10 times to 10 tons per year, and will take a stake in a GE plant in the U.S. expected to begin production by 2019. The GE plant likely will produce at least 100 tons of the fibers annually. GE will handle processing of the fibers.
Nickel alloy, a mainstay material in engine production, offers less heat resistance than silicon carbide fibers and requires air cooling. Silicon carbide fibers let planes use air more effectively for propulsion instead. The composite material costs more than nickel alloy, but producers hope that mass production will bring the cost down.
Silicon carbide fibers weigh one-third that of nickel alloy and can withstand temperatures up to 2,000 C. Besides aircraft engine parts, plans call for using ceramic composite materials made with the fibers in thermal power plant turbines. GE estimates the market for silicon-carbide-fiber-based components will grow 10-fold over the next decade.