OK, so this question actually stems from watching Star Trek (6).
Yesterday I re-watched the DVD and came up with a question during the scene when the Vulcan (Valoris?) makes a point of vaporizing a metal pot with a phaser. Chekov mentions vaporization as well.
So, a few questions.
How much energy is required to vaporize steel?
What gases would be released in such a process?
Also,
Is it currently possible to vaporize metal in such a manner to leave no toxic fumes and no ashes? (a la Star Trek?).
How much energy is required to vaporize steel? - Steel boils at about 3000 [sup]o[/sup]C. The actual amount of energy to reach this temperature depends on the mass of steel to be vaporized.
What gases would be released in such a process? - Steel vapor, plus any impurities in it, such as carbon.
Also,
Is it currently possible to vaporize metal in such a manner to leave no toxic fumes and no ashes? (a la Star Trek?). Yes. Powerful lasers do this routinely.
In analytical chemistry, metals are detected and quantified by burning them and measuring the “colour” if you like, of the flame
(the wavelength, as the white coaties call it)
When a pure metal is burned in air it produces the oxide of the metal, carbon dioxide, carbon monoxide, some metal nitrates and nitrites as well as water - in varying degrees.
Steel is not a pure metal, it is iron with other, strengthening materials added, carbon, tungsten, etc, so burning steel would result in the list up there, plus a number of other compounds, as a result of the additives, in composition with the iron.
However, as I doubt that steel can be burned in air becuase it would need at least pure oxygen to burn, you can take the nitrates and nitrites out of the picture.
So no, steel cannot be burned to nothing, as matter can be neither created or destroyed, but can only ever be converted into another form of matter. At least that’s what I learned at college
The temperature of the flame used to burn something depends on the composition of the thing you want to burn, the fuel used, and whether or not pure oxygen is used to feed the flame.
If you know what the composition of your steel is, there will be a proscribed temperature at which it will burn and a suggested fuel to use to attain this temperature. A judicious bit of Googling should turn that up for you.
In the lab, an acetylene and oxygen mix is often used for metals and for more complex mixtures, a technique called inductively coupled plasma (Ususally called ICP-MS as you need a Mass Spec stuck on the end of it to analyse the results) used which uses a magnetised argon gas plasma to heat the sample to some ridiculous temperature which I can’t remember now.
Sorry I wasn’t more detailed. Yes, I know steel melts quite easily (having worked with it for a good while in highschool shop).
So if steel becomes a liquid at 3K C, at what temp does it vaporize?
And is there a point in which, if enough energy is directed at the piece of steel, the steel would vaporize without the release of toxic gases? Basically like Q.E.D. mentioned with that laser, how much energy does that laser emit to vaporize steel?
A process called EDM or Electrical Discharge Manufacturing vaporizes metals in plain old air inside factories. An electrical discharge in close proximity to the work surface creates enough energy to vaporize a small section of the workpiece. Doing this repeatedly while precisely determining the location of the discharge on the workpiece can produce some remarkably complicated parts in a reasonable amount of time. It’s pretty amazing to see it in action.
The thing is, vaporized iron and carbon and the other goodies (“vaporized steel”) is a toxic gas. You don’t want to breath that stuff.
Don’t know how much energy is required… let’s say I weld – (i^2)rt = 192 joules to liquidize some steel if only for 1/60th of a second. Can’t say how much to vaporize, though. Although if you’re talking about energy it doesn’t matter if you’re talking laser or photon torpedos.
[aside]They must be using some sort of advanced method in ST; as I recall, the contents of the pot were left standing as the pot disintegrated around the outside. In any case, if the pot were simply vapourised, the people standing nearby would be seriously injured by the huge volume of searing hot vapour, furthermore, the vapour would eventually condense somewhere (probably everywhere).[/aside]
I think that there is some confusion here also… boiling point = vaporization point. “Vaporizing” doesn’t necessarily mean shooting some heat at it and the entire thing instaneously ceases to exist.
Apparantly, Star Trek phasers operate in a magical fashion to cause nearly all the matter “vaporized” to cease to exist. This doesn’t happen in the real world.
A few years ago, I was working on a homebrew high-power brushless motor controller when there was an insulation failure, and a mass of copper buss bar about the size of a dime was vaporized in an instant. The flash gave me a sunburn, the workship was full of smoke (although some of that was from the short-circuited battery packs), and there were little bits of ash floating around the workshop for some time. Vaporizing a larger mass of metal would have progressively more violent side effects on the environment.
Blow some air (or argon, etc) through an electric arc to create a “plasma jet”, then feed some metal wire slowly into this flame. Out comes metal vapor.
Yeah, what we really want is disintegration, i.e., we want to un-integrate it molecularly. This would cause something to cease to exist. Depending on the mass you want to disintegrate in this manner, you could cause a whole city – say Hiroshima – to cease to exist for a while.
Well, so we’re stuck with (1) vaporization where you have to worry about pools of your enemy forming at your feet later (never mind inhaling him!); (2) disintegration if you’re far enough away that the energy released won’t nuke you; or (3) some type of space-folding-worm-hole-black-hole transportation that’ll get someone far enough away from you that they’ll cease to exist anywhere close enough to you to matter.
One of the more interesting thin film/material scence deposition methods is pulsed laser deposition. You use a very high power laser beam to ablate (vaporize) a target material. The ejecta plume is then captured on a substrate.
