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Vibration Dampening in Chinook Helicopters with Tungsten Alloy

tungsten alloys vibration dampening absorption chinook helicopter

The Chinook helicopter was introduced over 50 years ago and it has undergone numerous modifications which have impacted its specifications and performance characteristics including size, weight, payload, engine equipment, etc. However, in general terms the Chinook helicopter has an empty weight of 24,578 lb and a maximum takeoff weight of 50,000 lb. Its fuselage is just under 99 feet in length (with rotors), with a width of just over 12 feet, and a height of just under 19 feet. The diameter of the helicopter's rotors is 60 feet. To power such an enormous helicopter the Chinook features two Honeywell T55-GA-714A turboshaft engines with FADEC. Its two engines produce a continuous power of 3,000 shp with a maximum power of 3,750 shp each.

In order to reduce the significant vibrations resultant from the forces generated by the aircraft, these helicopters employ Tungsten Alloy counterweights underneath the pilot and co-pilot seats to absorb and dissipate oscillations. Being able to fit a denser material (approximately 1.5 times denser than lead) into a smaller volume of space is essential to this application.


Rotor Balancing in Black Hawk Helicopters with Tungsten Alloy

tungsten alloys rotor balancing Black Hawk Helicopters

Introduced approximately 40 years ago, the Black Hawk helicopter has also experienced many design changes. Generally, the Black Hawk helicopter has an empty weight of 10,624 lb and a maximum takeoff weight of 23,500 lb. The Black Hawk's fuselage is just over 50 feet in length and just under 8 feet wide, with a height of just under 17 feet. Its main rotor is 53 feet and 8 in diameter. The Black Hawk's powerplant features two General Electric T700-GE-701C turboshaft, 1,890 hp (1,410 kW) each. The main rotor has a rotational speed of 258 RPM.

To help keep these extremely large rotors rotating smoothly at up to 258 RPM, the four main rotors in the Sikorsky Black Hawk has four Tungsten Alloy counterweights in each blade for static dynamic balancing purposes. Again, the ability to fit the extremely dense Tungsten Alloy (approximately 50% denser than lead) into a smaller volume of space is essential to keeping these rotors revolving in balance.


Tungsten Alloy Grades Available

Ed Fagan Inc. is a leading distributor of Tungsten Alloy. We supply Tungsten alloys in a number of grades, sizes, forms, and densities in both magnetic and non-magnetic.

Tungsten Alloy Physical Properties

EFI Grade

ASTM B777-15 Grade

Nominal Density GM/CC

Minimum Yield Strength KSI (MPa)

Minimum Ultimate Tensile Strength KSI (MPa)

Minimum Elongation %

Modulus of Elasticity KSI (MPa)

Class Hardness Rockwell "C" Max

EF 17

1

17.00

75 (648)

110 (758)

5

45 (310)

32

EF 17N

1

17.00

75 (648)

94 (648)

2

45 (310)

32

EF 175

2

17.50

75 (648)

110 (758)

5

48 (331)

33

EF 175N

2

17.50

75 (648)

94 (648)

2

48 (331)

33

EF 18

3

18.00

75 (648)

105 (724)

3

50 (345)

34

EF 18N

3

18.00

75 (648)

94 (648)

2

50 (345)

34

EF 185

4

18.50

75 (648)

100 (689)

2

52 (358)

35

N - Non-Magnetic Compositions


Other Tungsten Alloys Applications

Tungsten Alloys have many other commercial uses including radiation shielding, high temperature tooling and applications where a high density material is required in a limited volume of space such as counterweights in engines, emergency aircraft equipment, sporting equipment, etc.



For additional information on Tungsten Alloys, Physical and Mechanical Properties, Chemistry, Specifications and Forms; Click here to download a copy of our Tungsten Alloys Data Sheet.



For information on all our Refractory Metals and Alloys, Physical and Mechanical Properties, Chemistry, Specifications and Forms; Click here to download a copy of the Ed Fagan Inc. Refractory Metals and Alloys Data Sheet.


Call us now to speak with an EFI materials expert or to place an order.


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Soft Magnetic Alloys

Ed Fagan Inc. stocks a variety of soft magnetic alloys for wide range of applications. EFI carries:
Alloy 79
Alloy 50
Hiperco 50 & 50A
Vim Var Core Iron
Radiometal 4550

And we also have a large selection of other types of specialty metals and alloys for high technology applications, including:
Controlled Expansion Alloys
Electrical/Electronic Nickel
Refractory Metals and Alloys
Hard to Find Materials