The material. With a name like superalloy there has to be something special here. There is. Superalloy is a name applied to nickel-based, iron-based, and cobalt-based alloys that combine exceptional high-temperature strength with excellent corrosion and oxidation resistance. Without them, jet engines would not be practical: they can carry load continuously at temperatures up to 1200°C. The nickel-based superalloys are the ultimate metallic cocktail: nickel with a good slug of chromium and lesser shots of cobalt, aluminum, titanium, molybdenum, zirconium, and iron. The data in this record spans the range of high-performance, nickel-based superalloys.
Composition
Ni + 10 to 25% Cr + Ti, Al, Co, Mo, Zr, B, and Fe in varying proportions. General properties
|
Density |
7750 |
– 8650 |
kg/m3 |
|
Price |
*28.5 |
– 31.4 |
USD/kg |
|
Mechanical properties |
|||
|
Young’s modulus |
150 |
– 245 |
GPa |
|
Yield strength (elastic limit) |
300 |
– 1.9e3 |
MPa |
|
Tensile strength |
400 |
– 2.1e3 |
MPa |
|
Compressive strength |
300 |
– 1.9e3 |
MPa |
|
Elongation |
0.5 |
– 60 |
% |
|
Hardness—Vickers |
200 |
– 600 |
HV |
|
Fatigue strength at 107 cycles |
*135 |
– 900 |
MPa |
|
Fracture toughness |
65 |
– 110 |
MPa. m1/2 |
|
Thermal properties |
|||
|
Melting point |
1280 |
– 1410 |
°C |
|
Maximum service temperature |
*900 |
– 1200 |
°C |
|
Thermal conductor or insulator? |
Good conductor |
||
|
Thermal conductivity |
8 |
– 17 |
W/m. K |
|
Specific heat capacity |
380 |
– 490 |
J/kg. K |
|
Thermal expansion coefficient |
9 |
– 16 |
p, strain/°C |
|
Electrical properties |
|||
|
Electrical conductor or insulator? |
Poor conductor |
||
|
Electrical resistivity |
84 |
– 240 |
pnhm. cm |
Nickel is the principal ingredient of superalloys used for high-temperature turbines and chemical engineering equipment. On the left, a gas turbine (image courtesy of Kawasaki Turbines). On the right, a single superalloy blade.
|
Reserves |
6.3 X 107 |
– 6.5 X 107 |
tonne |
|
Embodied energy, primary production |
135 |
– 150 |
MJ/kg |
|
CO2 footprint, primary production |
*7.89 |
– 9.2 |
kg/kg |
|
Water usage |
*134 |
– 484 |
l/kg |
|
Eco-indicator |
4900 |
– 5500 |
millipoints/kg |
|
Ecoproperties: processing |
|||
|
Casting energy |
*3.38 |
– 4.09 |
MJ/kg |
|
Casting CO2 |
*0.20 |
– 0.24 |
kg/kg |
|
Forging, rolling energy |
*3.26 |
– 3.95 |
MJ/kg |
|
Forging, rolling CO2 |
*0.26 |
– 0.31 |
kg/kg |
|
Metal powder forming energy |
*11.3 |
– 13.6 |
MJ/kg |
|
Metal powder forming CO2 |
*0.90 |
– 1.09 |
kg/kg |
|
Recycling |
|||
|
Embodied energy, recycling |
33.8 |
– 37.5 |
MJ/kg |
|
CO2 footprint, recycling |
*1.97 |
– 2.3 |
kg/kg |
|
Recycle fraction in current supply |
22 |
– 26 |
% |
|
Ecoproperties: material Annual world production |
|
1.5 X 106 – 1.6 X 106 tonne/yr |
Typical uses. Blades, disks, and combustion chambers in turbines and jet engines; rocket engines; general structural aerospace applications; light springs, high-temperature chemical engineering equipment; bioengineering and medical.
