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chrisgedwards
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Super dense projectiles
Hey everyone,
I was watching show about deep sea diving the other day and got an idea. some deep sea diving suits are made from metal that is compressed into super
dense individual components that can handle the pressure of the deep sea.
I was wondering if it would be possible to compress a metal such as lead or depleted uranium so that the density was significantly higher. This super
dense projectile would carry much more energy than a projectile of the same size but of lower density.
after doing some searching, im not seeing anything regarding current technology similar to this. what do you guys and gals think?
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unionised
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I think the compressibility of metals is so absurdly small that this is nonsense.
Either the show was wrong or you misunderstood it.
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Mr. Wizard
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The energy of projectiles has nothing to do with the density, and is dependent on mass and velocity; E=1/2 m v^2. That said I know what you might be
asking is how the energy can be kept high while traveling through air and into a target. Most metals cannot be made more dense by compression then
returning to normal conditions.
As to metal being strong enough to handle pressure at great depths, I don't think the density has much to do with it. Some very dense metals are very
strong, but strength ultimately comes from the electrons bonding with each other, and their arrangement. Diamonds come to mind as an example of a
light material, with strong bonds, arranged in an optimal fashion for hardness. There is a general correlation between melting points and hardness,
but the different hardness between diamond and graphite show how important the arrangement is.
There was a joke once that Chevy Vegas were made of compressed rust
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neptunium
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only nature knows how to compress mater in the core of dying stars...
down here on earth we can make artificial diamonds by heating and compressing graphite but the atoms rearange themseves as previously explained..
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paulr1234
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There are many examples of technology 'systems' (frequently with military application) that are designed to perform optimally in extreme environments.
The Navy's current ADS (atmospheric diving suit) has joints that actually function better when at the intended depth (down to 2,000 feet).
So what you saw and heard probably wasn't referring to the properties of the materials that are used to make the individual suit components but rather
how they are designed to perform when subjected to pressure as complete system (or subsystem).
Anther interesting example are the fuel tanks for the old SR-71 spyplane. At the time of manufacture, there were no sealing materials that could
withstand the high frictional temperatures created by this aircraft. So instead the plane was designed to use a low volatility fuel (which was also
pumped around the fuselage as part of the cooling system) and the tanks and pipes were designed with metal on metal joints, that would leak a little
when on the ground.
As the plane took off and increased in speed, thermal expansion would seal the leaks and the plane would operate normally.
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chrisgedwards
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Ive been searching for the episode, no luck yet. They were compressing stainless steal (or aluminum? or titanium?) in large presses. this was
something i saw years ago, ill try to find it. I believe that the multiple ATM of pressure in the deep sea could compress the metal parts leading to a
malfunction in the suit. so the metal was pre-pressed. im not talking about density's similar to seen on black dwarfs, or anything like this. Metals
are high mass but other elements or compounds maybe heavy enough and more easily compressed?
meanwhile, superdense aluminum has been made with a process which involved a laser and a sapphire, which was small and hard to maintain http://www.sciencedaily.com/releases/2011/08/110 825152726.htm
The density does have to do with the energy the bullet caries. as was stated the energy of the projectile changes with the mass and velocity. A bullet
of lead of a certain volume will have less energy, when shot at the same velocity, than a bullet the same volume and shape made of highly compressed
(superdense) metal (or other material). I wonder if there is any technology that could contain the metal under this high pressure as a jacket, like
the copper on a lead bullet. Kevlar like. This could even be made to fragment on impact but that's getting ahead of things...
If the metal when compressed can be as heavy as 1.5x the weight, it can deliver a lot more energy. expensive ammo! maybe its the sort thing that could
be launched from a massive rail gun. There is also the idea of a hypervelocity highly heat resistant reentry projectile which falls/ is powered from
orbit and into the earth much like a meteorite. twice the mass could mean a lot more power.
obviously im asking just out of curiosity and to have the discussion, i know this is crazy stuff.
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Pulverulescent
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Quote: |
The density does have to do with the energy the bullet caries. as was stated the energy of the projectile changes with the mass and velocity. A bullet
of lead of a certain volume will have less energy, when shot at the same velocity, than a bullet the same volume and shape made of highly compressed
(superdense) metal (or other material). I wonder if there is any technology that could contain the metal under this high pressure as a jacket, like
the copper on a lead bullet. Kevlar like. This could even be made to fragment on impact but that's getting ahead of things... |
Déjà vu . . . again!
Non-military, sporting bullets are copper-plated to protect the interior (especially the rifling) of the barrel from the fouling effects of
the lead in the slug!
Lead-cored steel-jacketed bullets are of the military type . . .
Quote: | i know this is crazy stuff. |
You got that part right!
Superdense?
P
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Pulverulescent
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I'm not denigrating you or your posts, BTW ─ just saying you should take what's in "popular science" pubs. cum grano salis!
P
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Neil
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google "coin shrinking"
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chrisgedwards
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this is just something that popped in my head, thats all.
superdense is one search term i have been using when trying to find out of anything like this has been done. Superdense is also the term that was used
in the published paper i posted a link to.
I know what the purpose of the copper metal jacket is. What i was saying was, maybe if a material can be treated to make it superdense, to keep it in
this state, to contain it with a Kevlar (or something stronger) case to stop it from "inflating" or decompressing.
I have a 5 pound lead weight here in front of me, its for diving. feeling this lead, it really seems like with enough pressure it could be compressed
into a smaller calendar.
any idea what material has the highest density? i keep seeing osmium but that obviously would be out of the question for use because of the rarity. if
lead is 11.34g per ml numbers in the 50 to 100g/ml would lead to massive change in the energy. hypervelocity projectiles have been done, im sure this
is possible to some degree.
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chrisgedwards
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oh yes coin shrinking! how did that not come to mind? ill do some reading on it and see what its limits are. ive made a tesla coil and have started
but not finished a hv capacitor bank for coin shrinking, but this was like 6 years ago. thanks for the idea!
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watson.fawkes
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Quote: Originally posted by chrisgedwards | What i was saying was, maybe if a material can be treated to make it superdense, to keep it in this state, to contain it with a Kevlar (or something
stronger) case to stop it from "inflating" or decompressing. | In the case of a bullet, you want to decompress
always in the target and never in the barrel. This would require a mechanical failure rate less than, oh, 10^-6 say as not to kill shooters regularly.
Good luck with getting that to work.
Yes, the above paragraph is entirely sarcastic.
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Pulverulescent
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Quote: | google "coin shrinking" |
Interesting effect, this 'coin shrinking'; it's new to me . . .
And it's interesting too, that weight reduction seems to have escaped mention?
It's a 'surface electrical effect', obviously, and the fact that the vaporised metal layer seems so uniform and precise could, quite possibly
have applications in some field of engineering! Quote: | I know what the purpose of the copper metal jacket is.
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Do you not think that calling a few microns of copper plating a 'jacket' is stretching it just a bit?
And kevlar, FFS, is just a synthetic fibre!!!
Coin shrinking, considering the power-levels used, could result in producing a plurality of candidates for the 'Darwin Award'
P
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chrisgedwards
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really this is not something im planning on doing, just something i was curious about. why so much sarcasm?
is it really that strange to wonder if a bullet can be made of a material that is significantly more dense than lead?
im still looking but i did find Chengdeite which is iridium iron alloy. iridium cost a lot so in the last few years it looks like its gone from 500 to
1000$ an ounce. Chengdeite is Ir3Fe and has a density near 20g/cm3. Obviously too expensive. im going to keep looking, im sure there is something that
could work. The price of the round must also be considered against the cost of an explosive round that would do the same amount of damage.
it appears that coin shrinkers make the diameter of the coin smaller but the coin gets wider. i read that the density is not changed. im wondering if
electromagnetic forming can be used to increase the density. maybe if a container were used that did not allow for the width of the coin or projectile
to widen.
im trying to find the data but not having much luck (surprise!) on plutonium type implosion devices. im wondering about changes in density of the
resulting plutonium sphere when it is compressed by the shaped explosive charge.
anyone ever hear of a hypervelocity reentry projectile? something like a man made meteorite?
according to several sites, .50 caliber bullets have masses around 400g, lets call it a pound. imagine a .50 caliber bullet weighing in at 2-3 pounds
and the amount of energy it could do a supersonic speeds. i just think its an interesting idea.
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Sedit
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Sorry but its a little off topic, would the pressure at the bottom of the ocean be enough to form a diamond if the carbon was in the proper form at
the time? If so what would be the depth needed? I will run the numbers later if I have time but I am about to head out for the night and was curious.
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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chrisgedwards
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right now im reading up on degenerate matter. scientist have made degenerate matter in small amounts. This sor tof density is way more than required
to make such a projectile but the science is very interesting.
“This experiment resulted in something like a micro-explosion which turned the aluminium to a plasma state that swelled but had nowhere else to go,
creating gigantic pressure and dramatic changes in surrounding material properties and producing unfamiliar x-ray spectral lines.
http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1031...
concerning diamonds i found this (yes from wiki oh well) The process involves large presses that can weigh hundreds of tons to produce a pressure of 5
GPa at 1500 °C. bottom of the mariana trench is only 110 mpascals.
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Neil
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They took the idea of bundles of arrows fired from a catapult and made bundles of U238 and or Tungsten rods fired from an ICBM. The USA does ot use
them because the minute anyone anywhere see's an ICBM signature, red buttons get pushed.
So they do have re-entery weapons which are much denser then lead. look for lit on the new Trident missles.
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chrisgedwards
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of course whenever i have an idea its already been done. so much for the hypersonic superdense reentry weapon...
so now my focus is on making small superdense projectiles for use in railguns.
does anyone know anything about degenerate matter?
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Pulverulescent
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Quote: | does anyone know anything about degenerate matter |
"Degenerate matter" . . . that would seem to be Hawking Territory!
Heeeaaavveee . . . !
P
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Panache
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I'm going to get a
Degenerates Matter!, Tshirt made up. Might startup up a facebook page titled as such also. Actually i know absolutely i'll do neither of these two
things but my life is richer for the possibility of being able to.
Just made up a joke
Q: what did the talk show star's fanbase write on their protest banners after she was axed from the network?
A: Ellen Degenerates Matters!
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Pulverulescent
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Degenerate matter; wasn't that one of Hitler's pet hates?
Ooops! Sorry, I got Art and Matter mixed up!
Shit! I suppose I've Hodgkined the thread now . . .
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Neil
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Hissing noise made less noise
lol ellen.
degenerate matter would be a weapon all on its own as it would *pop* without the immense force needed to maintain its state. The energy needed to make
and contain degenerate matter is so far beyond anything you could even imagine that to put it in context you would be more likely to have a
breakthrough researching ways to cold fuse bananas to produce blast waves.
No human will ever *see* degenerate matter.
As for rail guns, leekage between the rails saps the propelling power. A railgun slug would need to be non-conductive Eg. Teflon coated.
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Pulverulescent
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Quote: | Hissing noise made less noise | Don't
you mean even less noise, Neil?
And anyway, the hissing noise in pulverulescent is 'silent' . . .
Just like the P in bath!
P
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Neil
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touche, I think? That felt like a mental rickroll.
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chrisgedwards
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Alright, im not being taken seriously.
Do you guys see an advantage to using a tungsten carbide jacketed projectile with 2-3x the density and thus mass per unit volume instead of a bullet
of the same size that is 1/2 or 1/3 the weight? less drag, less space, more energy. like shooting a 50 cal bullet from a 22.
This is the technochemistry section of science madness not weapons design so i wanted to keep my language research minded as opposed to mentioning
specifics on the projectile design and the damage it will do, hence terms such as pop etc. im trying to discuss basic science here with out upsetting
anyone but its proving difficult.
Obviously degenerate matter is huge overkill, i was using it as an extreme to show how matter can be compressed.
Meanwhile i have done some reading on the subject to try to keep these post on topic.
I am a biology student not and engineer which should be obvious and evidence that this is just out of curiosity..
Now am i right to believe that the youngs and bulk modulus of each material will determine how feasible it is to reduce the volume of a given mass? a
lot of the numbers i am seeing related to these equations appear to only be for elasticity and not compressability. where could i look?
As mentioned above machines used for making diamonds or explosives (also used for diamonds) are the two methods that could allow for the production of
these projectiles. Picking a material that is cheap enough to use is also essential (no iridium etc). Also since tungesten carbide and tungsten appear
to be the usual pieces used for these presses, am i right in believing that the same materials could not be used in one of these contraptions?
Looking at a few sites i see a list of the compressability of several types of materials. Ideally the material will already be quite dense (at least
10g/ml) and will have a very low energy of compressability.
anyone want to let me know if i am reading into the wrong thing? i wish i could find a proper calculator online that would easily tell me the
pressure needed to half or 1/3 or even quarter a materials volume.
Interesting combinations of super dense (good term), armor piercing, caseless ammunition is interesting. I am also wondering about rocket/typical
bullet hybrids modeled sort of like the original caseless ammo, the rocketball by walter hunt.
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