Aermet-100
Encyclopedia
AerMet alloy is an ultra-high strength type of martensitic alloy steel. The main alloying elements are cobalt
and nickel
, but chromium
, molybdenum
, and carbon
are also added. Its exceptional properties are hardness, tensile strength
, fracture toughness
, and ductility
. Aermet is weldable with no preheating needed. AerMet alloy is not corrosion resistant, so it must be sealed if used in a moist environment. AerMet is a registered trademark of Carpenter Technology Corporation.
Three types of AerMet alloys are currently available: AerMet 100 (also known as AerMet-for-Tooling), AerMet 310, and AerMet 340 alloy.
Examples of applications include armor, fasteners, airplane landing gear, ordnance, jet engine shafts, structural members, and drive shafts.
AerMet alloy is special in that it must be hardened twice in order to reach its maximum effectiveness. The first hardening application is a solution treatment at 1625 °F (885 °C) for 1 hour. It is then quenched to a temperature of 150 °F (65.6 °C) over 1 to 2 hours. It then must be cold treated, where the material is cooled to -100 F for 1 hour. The second hardening process is aging, where the material is heated to 900 °F (482.2 °C) for 5 hours.
AerMet 340 is hardened differently than the other two varieties. The first hardening application is a solution treatment at 1775 °F (968.3 °C) for 1 hour. It is then quenched to a temperature of 150 °F (65.6 °C) over 1 to 2 hours. The material may then be cold treated, where the material is cooled to -100 F for 1 hour. The second hardening process is aging, where the material is heated to 900 °F (482.2 °C) for 3 to 8 hours. If the cold treatment is skipped, the part can be aged twice to get the same results.
Cobalt
Cobalt is a chemical element with symbol Co and atomic number 27. It is found naturally only in chemically combined form. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal....
and nickel
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
, but chromium
Chromium
Chromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...
, molybdenum
Molybdenum
Molybdenum , is a Group 6 chemical element with the symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek , meaning lead, itself proposed as a loanword from Anatolian Luvian and Lydian languages, since its ores were confused with lead ores...
, and carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
are also added. Its exceptional properties are hardness, tensile strength
Tensile strength
Ultimate tensile strength , often shortened to tensile strength or ultimate strength, is the maximum stress that a material can withstand while being stretched or pulled before necking, which is when the specimen's cross-section starts to significantly contract...
, fracture toughness
Fracture toughness
In materials science, fracture toughness is a property which describes the ability of a material containing a crack to resist fracture, and is one of the most important properties of any material for virtually all design applications. The fracture toughness of a material is determined from the...
, and ductility
Ductility
In materials science, ductility is a solid material's ability to deform under tensile stress; this is often characterized by the material's ability to be stretched into a wire. Malleability, a similar property, is a material's ability to deform under compressive stress; this is often characterized...
. Aermet is weldable with no preheating needed. AerMet alloy is not corrosion resistant, so it must be sealed if used in a moist environment. AerMet is a registered trademark of Carpenter Technology Corporation.
Three types of AerMet alloys are currently available: AerMet 100 (also known as AerMet-for-Tooling), AerMet 310, and AerMet 340 alloy.
Examples of applications include armor, fasteners, airplane landing gear, ordnance, jet engine shafts, structural members, and drive shafts.
Properties
| Alloy | Carbon | Nickel | Cobalt | Chromium | Molybdenum | Iron |
|---|---|---|---|---|---|---|
| AerMet 100 Alloy | 0.23 | 11.1 | 13.4 | 3.0 | 1.2 | remainder |
| AerMet 310 Alloy | 0.25 | 11 | 15 | 2.4 | 1.4 | remainder |
| AerMet 340 Alloy | 0.33 | 12.00 | 15.60 | 2.25 | 1.85 | remainder |
| Alloy | Yield strength [ksi (MPa)] | Ultimate tensile strength [ksi (MPa)] | % Elongation | Charpy V-notch impact test [ft-lbs (J)] | Fracture toughness KIC [ksi-in½ (MPa-M½)] |
|---|---|---|---|---|---|
| AerMet 100 Alloy | 250 (1720) | 285 (1960) | 14 | 30 (41) | 115 (126) |
| AerMet 310 Alloy | 275 (1900) | 315 (2170) | 14.5 | 20 | 65 |
| AerMet 340 Alloy | 300 (2070) | 345 (2380) | 11 | 11 (15) | 34 (37) |
AerMet 100 Alloy
The UNS number is K92580. The alloy has a modulus of elasticity of 28,200 ksi and a density of 0.285 lbf/in3 (7.89 g/cm3). AerMet 100 alloy is somewhat more difficult to machine than 4340 at HRC 38. Therefore, carbide tools are usually used. Standard shapes that are available include round, sheet, welding wire, billet, plate, strip and wire.AerMet alloy is special in that it must be hardened twice in order to reach its maximum effectiveness. The first hardening application is a solution treatment at 1625 °F (885 °C) for 1 hour. It is then quenched to a temperature of 150 °F (65.6 °C) over 1 to 2 hours. It then must be cold treated, where the material is cooled to -100 F for 1 hour. The second hardening process is aging, where the material is heated to 900 °F (482.2 °C) for 5 hours.
AerMet 310 Alloy
AerMet 310 is harder and stronger than AerMet 100 alloy while maintaining ductility and toughness. Standard shapes include round bar, wire, billet, plate, and strip. AerMet 310 is hardened with the same procedure as AerMet 100.AerMet 340 Alloy
AerMet 340 alloy has a higher strength than AerMet 310.AerMet 340 is hardened differently than the other two varieties. The first hardening application is a solution treatment at 1775 °F (968.3 °C) for 1 hour. It is then quenched to a temperature of 150 °F (65.6 °C) over 1 to 2 hours. The material may then be cold treated, where the material is cooled to -100 F for 1 hour. The second hardening process is aging, where the material is heated to 900 °F (482.2 °C) for 3 to 8 hours. If the cold treatment is skipped, the part can be aged twice to get the same results.