April 1, 2015:
Ed Colvin (EC), VP, New Product Development and Introduction, Alcoa
Lynn Gambrill (LG), PW Chief Engineer, Manufacturing Engineering and Global Services.
Frank Preli (FP), PW Chief Engineer, Materials and Processes Engineering.
Jimmy Kenyon (JK), PW next-generation fighter engine general manager.
JK: We are seeing years of investment and technology starting to deliver new products and technology to the market (referring to the GTF): double digit fuel efficiency, 75% noise reduction. 20 years of technology investment. There are advancements in the engine core. At same time ramping up F35 engine. This is the world’s most powerful fighter engine but at the same time can adapt to vertical takeoff and landing.
Commercial demand going forward is going to have the need to control costs and more and more stringent regulatory demands (fuel, noise, emissions). As we’re getting to know the GTF intimately, it opens other pathways to future development for the next generation of geared turbo fan.
FP: When we take a look at materials, we look at cost, performance requirements, value, enhanced durability. In the GTF we looked at the propulsion section and the core, the fan blade, the composite case, fan blades with aluminum core and titanium, aerodynamic blade vs composite blade, materials core efficiency.The gear allows a smaller core.
In the future we’d like to improve core and fan efficiencies, including core thermo-dynamic efficiencies, including high temperature CMCs (advance materials).
LG: We consider manufacturing requirements for the future, and what will bring the customers the most value; cost opportunities, capacities for new launch products. About 80% of the parts in engines are made within the supply base.
EC: (Video) Aluminium Lithium is lighter, but denser material. Developing materials for GTF was a six year process. We bring great expertise in alloy, forging and casting, for thermal treatments. We were able to bring a process to fan blades that was unique. We have a third generation of Al Li development. We want to be able to use Al Li for any part of the airplane.
FP: When you get to fan blades of 12-16 ft in diameter, you get similar efficiencies of composite blades as with metal blades.
EC: There is a supply of titanium in the world other than Russia. It’s not scarce in the world, it’s a matter of concentration and cost.
IMHO al-lith alloys are less dense than standard Al (hence lighter)
see also 2050 from constellium use by airframe manufacturer and NASA
Al-Li alloys have been around since the 1920s like the Duralumin type Al alloys As mentioned they are less dense ( Li is the lightest metal) but are stiffer and have higher damage tolerance as well.
All planes would be made mostly of AL-Li alloys by now if there werent production and manufacturing difficulties.
The area of interest for the 777X could be AL-Li Fuselage sheet, moving away from pure structural components.
“EC: (Video) Aluminium Lithium is lighter, but denser materiaL.”
Just pointing out the slightly misleading comment
Re stiffness :thick. can be always tailored to adapt to structural needs
Re: DT,Agreed. CGR rates tend to improve & KIC is better.
re: manuf:: Agreed.for example porosity issues can decrease performance