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First time posting so hopefully this makes some sense!

I want to heat up a 28 gauge Nichrome wire to around 1,800-2,000 degrees Fahrenheit for short bursts at a time (about 5 seconds long). I'm curious as to how many "short bursts" I could do until the Nichrome wire wasn't usable anymore.

I know Nichrome can be used in electronic cigarettes, and for the extreme users, those coils can last about 2 weeks of consistent use (~100 puffs/day so 1,400 total uses). But from my understanding, their lifespan is only that long because the taste starts to go bad. Not because the wire is no longer heating up. If that is true, I'm wondering how long can a resistance wire last under those circumstances?

Another question I have is that I know electronic cigarettes reach a much lower temperature than 2,000 degrees Fahrenheit (around 500-600 degrees Fahrenheit) so would higher temperatures significantly reduce the life span of the wire? Or is it somewhat negligible?

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  • \$\begingroup\$ you have to provide a full description of your project (just anything that affects the nichrome wire) before any predictions can be made \$\endgroup\$ – jsotola Jan 25 '18 at 19:41
  • \$\begingroup\$ First: use Google to melting point of Nichrome wire. So long as you keep the wire to less than that temperature, you should have decent lifetime. \$\endgroup\$ – Dwayne Reid Jan 25 '18 at 19:56
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    \$\begingroup\$ maximum operating temperature of up to 1,250°C (2,280°F). I imagine Arrhenius aging rate also affects nichrome wire. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Jan 25 '18 at 21:21
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That's about 980-1093 °C, which is well beyond cherry red.

Things like hair dryers operate their elements around cherry red and electric bar heaters are about 900 °C, so you are going a bit beyond what is normally used for Nichrome. The hair dryers I've seen the insides of have the element supported on mica; electric bar heaters have the wire mounted on a refractory ceramic support, so you might need to do the same to avoid the wire drooping.

Looking around a bit, I found something about the cones used to measure temperature in clay-firing kilns which suggests to me that you would need an earthenware or porcelain support to avoid the actual support melting. I suspect, and you should confirm, that red clay is what household bricks are made of and that would not be sufficiently heat-resistant with a safety margin in mind.

I suggest that the answer is to do an experiment yourself - and make sure that nothing can catch fire around the experiment that you can't put out with the fire extinguisher that you have to hand.

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