Boeing’s new 777X wide-body passenger jet underwent its maiden flight on January 25, taking to the skies powered by two GE9X engines from GE Aviation, said to be the largest and most powerful commercial jet engines ever built. According to Eric M Gatlin, Additive Manufacturing General Manager at GE Aviation, each of the engines contains around 300 additively manufactured components.
GE Aviation has been working on the GE9X since 2013, and prior to the maiden flight the company stated it had carried out seventy-two test flights of the new engine, totalling more than 400 hours, on its Boeing 747 flying testbed. To date, the GE9X programme has reportedly completed more than 4,100 hours of ground and air testing, as well as 6,500 cycles.
The GE9X’s fan casing is over 3.4 m (134 in) in diameter, as wide as the body of an entire Boeing 737, and houses parts made from the a wide range of materials, including lightweight and heat-resistant ceramic matrix composites, and components made by Additive Manufacturing.
Almost 300 AM parts are reported to be in each GE9X engine, including many that combine multiple parts into one component, as well as parts that cannot be made in any other way. AM parts are produced at GE’s Avio Aero facility in Cameri, Italy and GE’s Additive Technology Centre in West Chester, Ohio, USA, and are reported to include fuel nozzle tips, low-pressure turbine blades, heat exchangers and inducers.
The inducer, used to remove dust, sand and other debris in the engine, is one such part which is difficult to make without using AM, and has never been used inside a commercial GE jet engine before. “The inducer cannot be manufactured any other way, except by 3D printing,” stated Zach Studt, Senior Manufacturing Engineer at GE Aviation. “In this way, additive is unlocking performance of the engine. A different manufacturing process can deliver a better product. Going forward, most engines will probably come with some version of that inducer.”
The titanium aluminide (TiAl) blades on the low-pressure turbine of the GE9X are also produced by metal Additive Manufacturing. The TiAl blades are said to be roughly half the weight of traditional nickel-alloy turbine blades and are produced at Avio Aero using Arcam EBM systems.
GE Aviation is reported to be wrapping up certification testing for the GE9X and expects the engine to be certified later this year. It has built ten compliant engines, eight of which will go on flying test airplanes, plus two spares, for Boeing. Engines for the first three aircraft have been delivered and the balance will be in Seattle in the coming weeks. GE has received orders for more than 700 GE9X engines.