Aermet

Aermet special ultra-high strength type of martensitic 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. It is a registered trademark of Carpenter Technology Corporation.

There are four types of aermet available: aermet 100, aermet 310, aermet 340, and aermet-for-tooling.

Properties

Properties of aermet alloys in hardened state

Alloy	Yield strength [ksi (MPa)]	Ultimate tensile strength [ksi (MPa)]	% Elgonation	Charpy V-notch impact test [ft-lbs (J)]	Fracture toughness KIC [ksi-in½ (MPa-M½)]	Density [lbf/in3 (g/cm3)]
Aermet 100	250 (1720)	285 (1960)	14	30 (41)	115 (126)	0.285 (7.89)
Aermet 310	275 (1900)	315 (2170)	14.5	20	65	0.285 (7.89)
Aermet 340	300 (2070)	345 (2380)	11	11 (15)	34 (37)	0.285 (7.89)
Aermet for tooling	260 (1790)	300 (2070)	12	20	-	0.285 (7.89)

Chemical Composition

The alloy composition of Aermet-100 is:

• Carbon minimum 0.2%, maximum 0.33% by weight
• Chromium minimum 2%, maximum 4%
• Nickel minimum 10.5%, maximum 15%
• Molybdenum minimum 0.75%, maximum 1.75%
• Cobalt minimum 8%, maximum 17%
• Remainder iron

Mechanical Properties

Aermet-100 is heat treated at 1625°C for an hour. It then can be aged for 5 to 8 hours to a tensile strength of 280-300 ksi or 290-310 ksi at temperatures of 900°C and 875°C respectively. In use, Aermet-100 must be kept away from moisture as it is not corrosion resistant. The alloy has a modulus of elasticity of 28,200 ksi. A table of properties can be found here. [1]

External links

• [2]
• [3]