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There is something that can stand that much temperatures ? or that kind of Welding can evaporate or melt everything ? I read that nothing could stand more than 7000 ° C, but i want to be sure, also, why nothing can stand that much?

There is something you could do to make a material able to stand that thing directly ?

I'm just looking for a material that could work for temporary protection, against a plasma weapon who is similar to a plasma arc welding, but more portable.

I would appreciate if someone clarifies my doubts, thanks!

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  • $\begingroup$ Can you clarify what is the worldbuilding aspect here? $\endgroup$ – L.Dutch Mar 16 at 8:34
  • $\begingroup$ Oh Sorry! I'm going to edit again, i was looking for a material who can stand a weapon that is pretty similar to a plasma arc welding $\endgroup$ – Invasor Mar 16 at 9:23
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    $\begingroup$ Your question (why no material can withstand really high temperatures) seems better suited for physics. $\endgroup$ – L.Dutch Mar 16 at 9:43
  • $\begingroup$ For how much time? And what's the hot medium? For example, my hand can easily withstand being put in a 7000 ° C hot oven for one millisecond. On the other hand, one second in 100 ° C will damage it irreversibly. $\endgroup$ – AlexP Mar 16 at 12:41
  • $\begingroup$ m.jagranjosh.com/current-affairs/… hafnium Carbide can withstand 4000 celcius which is about 7200 fahrenheit. But I expect that its better to use the kinetic energy protection: its not about making the material survive but the occupant. If the material survives but the wearer still burns its useless as armor. $\endgroup$ – Demigan Mar 16 at 16:40
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Graphite is the pure carbon stuff of pencil leads. It is used in high temperature crucibles.

graphite crucibles http://www.slvindustries.com/graphite-crucible-temperature-range.php

GRAPHITE CRUCIBLES - TEMPERATURE RANGE

The crucible material must have a much higher melting point than that of the material used in it for processing. Graphite crucible can withstand high temperatures, are chemical and thermal shock resistant. Graphite crucible is ideal for the melting of Aluminium, Copper, etc.

Graphite Crucible Temperature Range can go as high as 5000°F and can be used in furnaces and high heat processes.

It is rated stable up to 6700F - provided there is not oxygen to oxidize it. At higher temperatures, absent oxygen, it degrades by sublimation which I found in the abstract of this article looking at graphite for atmospheric re-entry shields. Pure carbon vapor is a weird thing to think about. Probably it turns back into soot pretty fast. Stuff will get dirty during this fight.

Even if there is oxygen, at those very high temperatures the density of oxygen ready to react will be very low, and the escaping CO2 from oxidizing graphite will tend to make a cloud of CO2 over the graphite, which will protect it from incoming oxygen. You will in essence have an ablating heat shield, which can disperse heat by gradually reacting away.

A nice thing for your story is graphite is familiar. If I read about an exotic supermaterial like silicon carbide in the context of a fiction I would assume it was made up by the author. Readers will be familiar with graphite as a substance. Your heat shield will be a badass matte black,. Also the ablating heat shield will make all kinds of smoke and gas which will be impressive.

And you could use your heat shield to sketch insulting pictures of your enemy. Your sidekick can carry an eraser.

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    $\begingroup$ Graphite is an excellent “welding shield”. It’s cheap, replaceable, light and portable, and does not melt. $\endgroup$ – Gimelist Mar 16 at 20:29
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    $\begingroup$ Even if there’s oxygen around and you damage the shield, get a new one. Graphite is light and easy to carry and cheap. We got loads of this in our lab. $\endgroup$ – Gimelist Mar 16 at 20:31
  • $\begingroup$ @Gimelist - is it badass matte black? $\endgroup$ – Willk Mar 16 at 21:23
  • $\begingroup$ even better: it can be polished to a shiny smooth black that will reflect some of the energy back to the attacker $\endgroup$ – Gimelist Mar 16 at 22:16
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Why can nothing stand that temperature? Because temperature is one measure of the energy in a substance and all chemical bonds are subject to breakage if sufficient energy is applied. Above 7000 C (in fact probably above 6000 C) there are no known substances with bonds that are sufficiently strong to resist breakage and all material substances will decompose and vaporise.

Temporary protection could be achieved by use of a heat shield that ablates or wears away like the heat shields used on space craft. The surface absorbs energy up to some fairly high level and then decomposes and the decomposition products carry away the excess energy leaving a fresh layer underneath to soak up more energy as so on.

There is no reason why the material used has to be a solid. In fact Elon Musk’s new Starship spacecraft proposes to use methane to carry away the heat of re-entry. The heat shield will leak methane through millions of tiny holes. As the methane passes through the heatshield it will absorb heat from it and carry that heat away.

Another approach would be to use a strong magnetic field that would deflect the hot plasma of the welding arc preventing it from reaching the surface. This approach is used in developmental thermonuclear reactors to contain plasma.

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