A Nickel-Iron-Cobalt, controlled expansion alloy containing 29% Nickel.
Its coefficient of expansion (which decreases with rising temperature to
the inflection point), matches the expansion rate of borosilicate glasses
and alumina ceramics.

Applications include:

  • Glass to metal seals in applications requiring high reliability or resistance to thermal shock, ie. high power transmitting valves
     
Approximate Chemical Composition
Ni 29%
Fe 53%
Co 17%
DENSITY 8.16 g/cm3 0.295 lb/in3
MELTING POINT 1450oC 2640oF
INFLECTION POINT 450°C 840°F
THERMAL CONDUCTIVITY 16.7 W/m•°C 116 btu•in/ft2•h°F
COEFFICIENT OF EXPANSION 6.0 µm/m °C
( 20 - 100°C)

4.6-5.2 µm/m °C
( 20 - 400°C)

3.3 x 10-6 in/in °F
( 70 - 212°F)

2.6-2.9 x 10-6 in/in °F
( 70 - 572°F)

 

HEAT TREATMENT (AFTER FORMING)

The Nilo alloys are usually used in the annealed condition (residual cold work distorts the coefficients of thermal expansion.

Anneal at 850 - 1000°C (1560 - 1830°F)

 
CONDITION  

APPROX TENSILE STRENGTH

 

APPROX SERVICE TEMPERATURE

Annealed 450-550 N/mm2 65-80 ksi up to 400oC up to 750oF
Hard Drawn 700-900 N/mm2 102-131 ksi up to 400oC up to 750oF
 
STANDARDS
ASTM F15
 


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