GE9X, a partnership that pushes the limits of our know-how

 

On September, GE Aviation announced that its GE9X turbofan engine has been certified by the FAA, a key milestone in the propulsion system of the Boeing 777X long-haul jet.

Safran Aero Boosters, GE's partner on the GE9X engine, has full responsibility for the low-pressure compressor (financing, development, production and assembly), as well as the manufacturing of the fan disk, representing 5% of the engine.

Selected by Boeing as the exclusive engine for the 777X, the GE9X will reduce fuel burn by 10% compared to the one currently in the field (GE90), fitted to 777 aircraft. The largest version—the future 777-9X powered by these engines—will be able to carry 400 passengers over 15,000 kilometers.

This certification marks once again the good collaboration between GE and Safran Aero Boosters, both partners on the F110 (F15 and F16), CF34-10 (Embraer 190/195 & Comac ARJ21), GEnx (Boeing 787 and 747-8) and GE Passport (Bombardier 7500) engines. As world leader of the low-pressure compressor on medium-haul aircraft, Safran Aero Boosters is now asserting its position on the long-haul market.

 

State-of-the-art technology for the manufacturing of fan disks: a closer look at inertia friction welding

To ensure the manufacturing of ever more optimized fan disks, Safran Aero Boosters has developed expertise in a cutting-edge process that only a handful of players in the aeronautics industry have: inertia friction welding. This technology is used at the Milmort site to weld the fan disks of the GEnx-1B/-2B (Boeing 747 and 787) and GE9X (Boeing 777X) engines.

The principle is that the friction and high pressure (in the order of 1,000 metric tons) between the two components produce enough heat to weld the two parts together. In practical terms, a component is rotating at 200 rpm, accumulating energy through inertia, and then pressed firmly against a second component that is maintained static. This process ensures the uniformity of the mechanical properties of the material as well as a precise, compact and light assembly.

The tooling diameters are almost two meters and the flywheels are four. In total, the equipment is about ten meters long and weighs around 500 tons; record dimensions for an out of the ordinary machine, to which other equipment (heat treatment, machining and ultrasonic control) is added to enable an integrated line.

 

What is a fan disk?

The fan disk is the component at the front of the engine to which the fan blades are attached. The fan disk has to support a pressure on each dovetail equivalent to 170 tons.