Nickel Superalloys & Turbine Blades
Nickel alloys such as Nimonic (1941) stay strong red-hot; vacuum casting and single-crystal blades later let jet engines run in gas hotter than the metal could survive without cooling.
Open in the interactive tree →Nimonic 80 (1941), developed at the Wiggin works for Whittle's jet engines, strengthened a nickel-chromium matrix with tiny Ni3(Al,Ti) crystals. Vacuum melting (about 1950) removed impurities; directional solidification and single-crystal casting, developed at Pratt & Whitney from the early 1960s, removed the grain boundaries along which blades creep. Single-crystal blades entered military engines in the 1970s and commercial engines in 1982, and rhenium additions later raised the service temperature by about 30 to 60 °C. Turbine gas at about 1,750 K is now hotter than the alloy's incipient melting point (about 1,600 K), so internal air cooling and ceramic coatings keep the metal alive.
Prerequisites
- Metallurgy (Bronze, Iron)~2500 BCNickel alloys are melted, cast and heat-treated with the methods of metallurgy
- Turbojet Engine1937Jet-engine turbines created the demand: blades glow red-hot under huge centrifugal load
Unlocks
- Jet Airliner1952Airliner turbines run on nickel-alloy blades