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Rodar® Strip and Foil

Rodar® is an Iron-Nickel-Cobalt alloy with an unique linear thermal expansion coefficient. It is also stable to cryogenic temperatures. This combination of characteristics has prompted its application in electrical package sealing of glass/metal and ceramic/metal.

Rodar® can be formed and deep drawn from the annealed temper. A 1/8 hard temper is optimum for heavy piercing.The material can be joined to other metals by welding, brazing, and soldering. The joint design must consider that Rodar® has a lower expansion coefficient than most other metals.

Available Sizes:

Rodar® is available from Hamilton Precision Metals as strip product in thicknesses from 0.001” to 0.060” (0.0254 mm to 1.524 mm) and width up to 12.0” (304.8 mm). The material conforms to ASTM F15, AMS 7728 and UNS K94610.

Nominal Composition
Nickel 29.0%
Cobalt 17.0%
Iron Balance

Mechanical Properties
Ultimate Tensile Strength 75,000 PSI
Yield Strength (0.2% Offset) 50,000 PSI
Elongation in 2” * 30%
Modulus of Elasticity (Tension) 20 x 106 PSI
Poisson’s Ratio 0.317

*The measured elongation will be less as thickness decreases to 0.002” and less.
These values may be adjusted by control of process variables – consult HPM for desired values

Physical Properties
Density 0.302 lbs/
Melting Point (Approx.) 1455°C
Electrical Resistivity @ R.T. 49 Microhm·cm
Temperature Coefficient of Resistivity (25° to 100°C) 3700 PPM/°C
Thermal Expansion Coefficient (30° to 400°C) 4.9 x 10-6/°C
Thermal Conductivity @ 100°C 16.7 W/m·K
Curie Temperature 435°C
Magnetic Attraction Yes

Typical values to guide alloy selection but are not a guarantee of minimum or maximum.
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