Engine maker GE Aviation has just announced it is using durable, lightweight composite components in the hot section of a jet engine, a veritable technical achievement that has eluded the engineering community for many moons.
The business says that the GE Rolls-Royce Fighter Engine Team's F136 development engine for the Joint Strike Fighter now features third-stage, low-pressure turbine vanes made by GE from ceramic matrix composites (CMC).
GE - Aviation, with responsibility for 60 percent of the F136 program, is developing the core compressor and coupled high-pressure/low-pressure turbine system components, controls and accessories.
GE Aviation is pretty excited about CMC development and is applying it as an enabling technology in several of its private and government-funded engine demonstrator programmes.
The news could lead to the first commercial use of CMCs in a jet engine's hot section (combustor and turbine areas) when a F136-powered JSF begins flight testing in 2010.
If flight testing proves as succesful as GE hopes, CMC components could well become a civil cornerstone for the company's next-generation jet engines for narrow-body, regional, and business jets.
The benefits of ceramic turbine components work by significantly increasing the efficiency of engines through both higher temperature capability and lower ceramic density.
There is a catch, however. Ceramics are also well known for their tendency to fail in a brittle, catastrophic fashion so GE scientists at GE Global Research, GE Aviation and GE Energy have been working to develop CMC materials that combine the high temperature resistance of ceramics with the mechanical toughness normally associated with metals.
GE researchers have used silicon carbide fibres, roughly 1/6th the diameter of a human hair, to reinforce a silicon carbide matrix and give a strong and tough ceramic composite material.
Check out this video on GE's ballistic impact test posted on the GE Global Research blog From Edison's Desk which shows how careful engineering of the bonding between the fibres and matrix yields a CMC material that is many times tougher than traditional ceramics.
