High Density Reactive Materials

[DB]

I have just read this story from the BBC News website.

 

It is, quite possibly, the worst technical story I have ever had the misfortune to read, and it links to the ONR, where the abstract has the highest newspeak quotient I've seen outside of a dodgy sociology-sourced statistical presentation.

 

Anyone have any idea as to what they have actually "invented" here?

[Guest Jason L]

I have just read this story from the BBC News website.

 

It is, quite possibly, the worst technical story I have ever had the misfortune to read, and it links to the ONR, where the abstract has the highest newspeak quotient I've seen outside of a dodgy sociology-sourced statistical presentation.

 

Anyone have any idea as to what they have actually "invented" here?

 

Ha. I was just blasting this not 10 minutes ago?

 

The bigger picture is this: there has been considerable interest for oh the past 10 years or so for materials that are structural (ie that are strong enough to be meaningfully load bearing) but are also variously reactive.

 

The holy grail is obviously a structural material that is actually detonable, but that's IMO a foolish pipe dream. Some Russians actually claimed they created a quasi-detonable metal ceramic but that has IMO been completely debunked by western research. Now while some of the PBXs are beautifully plastic-like, they are neither strong enough, nor exceptionally dense which is bad.

 

So the best you can hope for IMO is a material that is metal like in strength and density, but that reacts on a reasonable time-scale with the detonation event in the explosive filler. Something somewhat akin to a thermobaric, but where the reactive/energetic material forms the casing of the bomb and thus does not rob from the actual peak explosive yield with some added benefits (or not depending on the reactive casing).

 

The trick is this, no monolithic or quasi monolithic casing can be broken down small enough to react in the detonation/blast flowfield, which means you need to turn to some sort of composite that embeds some sort of reactive particulate small enough to react while forming a structure strong enough to withstand firing forces of a missile or from a gun.

 

This is being worked on in a whole slew of places - if I had to guess it was another formulation involving various epoxies, composites and integrating tungsten powders for reactivity and density.

[Doug97]

I agree that the article is terrible - every statement seems to contradict every other statement.

 

For example, how can a missile with 5 times the explosive power reduce collatoral damage? Is it because all of the casing is consumed so that there is no shrapnel?

[Guest Jason L]

I agree that the article is terrible - every statement seems to contradict every other statement.

 

For example, how can a missile with 5 times the explosive power reduce collatoral damage? Is it because all of the casing is consumed so that there is no shrapnel?

 

It won't have 5x the explosive power. 5x the energy yield maybe.

 

Yeah, damage template is smaller since frags reach out much further than blast and for a proper reactive casing most of it should be promptly consumed.

[DB]

I agree that the article is terrible - every statement seems to contradict every other statement.

 

For example, how can a missile with 5 times the explosive power reduce collatoral damage? Is it because all of the casing is consumed so that there is no shrapnel?

I think that what they were trying to say is that the proposed new munition has 5x the "power" of the inert munitions that have been the alternative for low collateral damage missions - think "concrete bombs". The alternative - that they have created a new explosive composite material that is 5x more powerful than current explosives seems to be a little bit unlikely.

 

If you then assume that they switch comparisons to equivalent yield conventional munitions, you end up where Jason is coming from - the casing fragments "shrapnel" have the potential to create more serious collateral effects.

[Guest Jason L]

I think that what they were trying to say is that the proposed new munition has 5x the "power" of the inert munitions that have been the alternative for low collateral damage missions - think "concrete bombs". The alternative - that they have created a new explosive composite material that is 5x more powerful than current explosives seems to be a little bit unlikely.

 

If you then assume that they switch comparisons to equivalent yield conventional munitions, you end up where Jason is coming from - the casing fragments "shrapnel" have the potential to create more serious collateral effects.

 

Well, I've seen 5x the effective lethality for something made with an HDRM casing over a conventional casing being thrown about in various PR pieces and presentations. No clue how you can measure lethality that way but that is maybe where the 5-fold bit came from.

 

If you take the entire mass of casing and turn it into something with high specific energy of combustion in air its actually pretty easy to increase the energy yield of the bomb by several factors too. But it wont have 5x the power or 5x the explosive yield or 5x the destructive potential.

[shep854]

From StrategyPage:

http://www.strategypage.com/htmw/htweap/articles/20110824.aspx

" Thus when the explosives in the missile, bomb or shell go off, the HDRM shell of the projectile explodes as well. This can increase the explosive effect by up to five times, while reducing the metallic projectiles by over 90 percent. It’s the metallic projectiles (shrapnel) that causes more distant casualties. "

Does this sound logical?

[Guest Jason L]

" Thus when the explosives in the missile, bomb or shell go off, the HDRM shell of the projectile explodes as well. This can increase the explosive effect by up to five times, while reducing the metallic projectiles by over 90 percent. It’s the metallic projectiles (shrapnel) that causes more distant casualties. "

 

Logical, but technically impossible (right now) AFAIK. No one is anywhere close to my knowledge of creating a structural explosive at this time. If they did it would be fabulously big news.

 

React quick enough to enhance the detonation: yes, detonate as well: no.

[shep854]

Jason, your sig line is truly appropriate!

[toysoldier]

Logical, but technically impossible (right now) AFAIK. No one is anywhere close to my knowledge of creating a structural explosive at this time. If they did it would be fabulously big news.

 

React quick enough to enhance the detonation: yes, detonate as well: no.

 

Can´t they cheat to it? Like, making a composite shell. Alternally layered, or on a lattice. Or is that unfeasable aswell?

[DougRichards]

Logical, but technically impossible (right now) AFAIK. No one is anywhere close to my knowledge of creating a structural explosive at this time. If they did it would be fabulously big news.

 

React quick enough to enhance the detonation: yes, detonate as well: no.

 

Nipolit?

[Guest Jason L]

Nipolit?

 

Kinda? That falls under my description of "Now while some of the PBXs are beautifully plastic-like, they are neither strong enough, nor exceptionally dense which is bad."

 

Perfect for something that just needs to be thrown and machinable PBX explosives are the go-to to type for high precision warheads where you absolutely need a high degree of homogeneity and geometry accuracy, but you can't build a whole aerospace structure or a high speed shell out of it. PBXs have UTS on the order of a few thousand PSI compare to 10 thousand + for high strength plastics, and even worse shear strengths.

 

Nipolit is far from the only explosive that uses DEGN as a plasticizer either, several allied WW2 formulations used it and of course in certain dynamite formulations do too.

 

I think Nipolit got blown out of proportion through some badly done research and the tendency towards sensationalizing Nazi military engineering/science.

[Guest Jason L]

Can´t they cheat to it? Like, making a composite shell. Alternally layered, or on a lattice. Or is that unfeasable aswell?

 

Yeah, but the behaviour of laminated systems isn't trivial compared to the conventional "big chunk of explosives surrounded by a casing" scheme. Also, it's quite unclear that laminated systems actually add anything in terms of performance for all the extra effort involved.

[CaptLuke]

I think Nipolit got blown out of proportion through some badly done research and the tendency towards sensationalizing Nazi military engineering/science.

 

"Blown out of proportion" as in wouldn't really have worked for the grenade applications? or as in didn't really provide an advantage over conventional grenade designs? or as in "maybe good work for a limited application but not a breakthrough nor anything other countries couldn't have done?" Just curious.

[Guest Jason L]

"Blown out of proportion" as in wouldn't really have worked for the grenade applications? or as in didn't really provide an advantage over conventional grenade designs? or as in "maybe good work for a limited application but not a breakthrough nor anything other countries couldn't have done?" Just curious.

 

The latter two. A regularly fragmenting casing with an inner filler works better as a grenade in the first place. Any number of formulations of melt castable explosives that plasticize relatively hard could be used as some sort of grenade as well, and these were no secret to anyone.

 

Also there was all sorts of talk of how it was top secret stuff the allies had lots of interest in because you could make bridges and warhead noses and all sorts of other stuff out of it, etc, mind you that same reference claims that PETN was some secret formulation as well so.....

[DougRichards]

The latter two. A regularly fragmenting casing with an inner filler works better as a grenade in the first place. Any number of formulations of melt castable explosives that plasticize relatively hard could be used as some sort of grenade as well, and these were no secret to anyone.

 

Also there was all sorts of talk of how it was top secret stuff the allies had lots of interest in because you could make bridges and warhead noses and all sorts of other stuff out of it, etc, mind you that same reference claims that PETN was some secret formulation as well so.....

 

Well it is just useful to remember that it was developed almost 70 years ago, and there must have been some improvements on material science since.

 

There were also some applications where a metal casing was not required, such as a blast mine, some of which used wood or glass so as to be less detectable. For grenades the British 'Gammon' grenade would seem an appropriate device to mention, essentially a small blast grenade, with little fragmentation.

 

In terms of using something like Nipolit in a bomb, a small aircraft bomb, say 50k, with plastic or even plywood fins, may provide something intermediate between a solid concrete bomb and a full on blast / fragmentation.

[rathi]

Our brilliant engineers created a fragmentation free offensive grenade 70 years ago by slapping some TNT into a cardboard shell. Thermobaric weapons considerably improve bang for a given sized warhead. Other than significantly improved buzzword density, I don't really see what is so special about this project.

[Guest Jason L]

Well it is just useful to remember that it was developed almost 70 years ago, and there must have been some improvements on material science since.

 

Yes, but not to the level of making an explosive structural material with any significant strength

 

There were also some applications where a metal casing was not required, such as a blast mine, some of which used wood or glass so as to be less detectable. For grenades the British 'Gammon' grenade would seem an appropriate device to mention, essentially a small blast grenade, with little fragmentation.

 

Sure, but that can be achieved using just about any explosive and a plastic casing.

 

In terms of using something like Nipolit in a bomb, a small aircraft bomb, say 50k, with plastic or even plywood fins, may provide something intermediate between a solid concrete bomb and a full on blast / fragmentation.

 

Why would you want to? The purpose here is to deposit more destructive power into a smaller template by eliminating far-flung fragments, not to create a somewhat weaker bomb.

[Guest Jason L]

Our brilliant engineers created a fragmentation free offensive grenade 70 years ago by slapping some TNT into a cardboard shell. Thermobaric weapons considerably improve bang for a given sized warhead. Other than significantly improved buzzword density, I don't really see what is so special about this project.

 

Thermobarics mostly make seriously inferior metal benders, which is a pretty huge part of warhead design.

Edited August 29, 2011 by Jason L

[toysoldier]

Damn, i can´t remember where i read about some material that could withstood extreme stress very well only once, but henceforth it would be as brittle as to pulverize. Am gona google-fu for it.

[Guest diorbetrida]

Fellas

Did anyone tried the magic flight vaporizer? I'm want to buy it and i'm comparing the prices of different sites and also looking for reviews. Found it on this site the cordless vaporizer with a titanium 4pc grinder and portable pollen press included for $129 - it worths it?!

[Max H]

Damn, i can´t remember where i read about some material that could withstood extreme stress very well only once, but henceforth it would be as brittle as to pulverize. Am gona google-fu for it.

I could see that being useful for HESH rounds - strong in the barrel, weak at the target. and I wonder what it'd do if you made ERA out of it?