[Ponchis]

What is the emissivity of Nifethal?


I will really appreciate it.
Thanks

[Arkcon]

Its hard to understand in what sense you mean this, we need more context.  I recognize that Nifethal is a metal with a fairly high resistance, but without heating it or an electric current, it won't emit any radiation.  Unless you mean something else.

[Enthalpy]

Emissivity depends fundamentally on the temperature, especially for metals. It easily climbs from 0.1 at 300K to 0.5 when hot - for a clean metal.

Since this alloy isn't much protected against oxidation, emissivity depends a lot on the surface cleanliness. If, say, the wire is coloured after a high-temperature trip, it will emit a lot more than if it's blank, for instance 0.5 instead of 0.2.

There would be some nasty details more, like: total emissivity (the most common one) or in some directions and around some wavelengths.

Having checked that, and because emissivity data is scarce, I suggest to pick data from a similar alloy, like Invar  (36% Ni, rest Fe) or Permalloy. Do not take one containing Cr, Al nor Ti - but FeCo would resemble FeNi.

http://www-eng.lbl.gov/~dw/projects/DW4229_LHC_detector_analysis/calculations/emissivity2.pdf

Maybe you hoped to get a two-digit answers... Sorry, emissivities are by nature imprecise, above all for metallic surfaces. Satellite designers do need accurate emissivities, but for that they expose no blank metal: all is anodized, and only perfectly known materials (preferably polymer films or ceramics and glasses) are used as control surfaces, with an accurately controlled cleanliness.

[Ponchis]

Emissivity depends fundamentally on the temperature, especially for metals. It easily climbs from 0.1 at 300K to 0.5 when hot - for a clean metal.

Since this alloy isn't much protected against oxidation, emissivity depends a lot on the surface cleanliness. If, say, the wire is coloured after a high-temperature trip, it will emit a lot more than if it's blank, for instance 0.5 instead of 0.2.

There would be some nasty details more, like: total emissivity (the most common one) or in some directions and around some wavelengths.

Having checked that, and because emissivity data is scarce, I suggest to pick data from a similar alloy, like Invar  (36% Ni, rest Fe) or Permalloy. Do not take one containing Cr, Al nor Ti - but FeCo would resemble FeNi.

http://www-eng.lbl.gov/~dw/projects/DW4229_LHC_detector_analysis/calculations/emissivity2.pdf

Maybe you hoped to get a two-digit answers... Sorry, emissivities are by nature imprecise, above all for metallic surfaces. Satellite designers do need accurate emissivities, but for that they expose no blank metal: all is anodized, and only perfectly known materials (preferably polymer films or ceramics and glasses) are used as control surfaces, with an accurately controlled cleanliness.

Thanks for your time and sorry for the delay. Your answer was really very helpful. Really, thanks for your time.