Sciencemadness Discussion Board

Substitute

BPS - 20-8-2017 at 09:35

I am wondering if an ammonium perchlorate oxidiser based, black powder substitute for use in bp firearms will work well.
There are some such compositions on the market but most either leave very corrosive , or unacceptable levels of fouling.
The oxidiser in most is metallic perchlorates and/or nitrates, the byproducts of which are corrosive salts.
I am thinking if perhaps an AP based mix, with maybe Carbon as fuel would work and deflagerate with predictable consistency.

Has anyone been down this road ?

Laboratory of Liptakov - 20-8-2017 at 13:46

Best will, try it. AP 80 + C 20 = OB on CO2 -26,1

BPS - 21-8-2017 at 05:24

Might try it out if I can get hold of some AP.
Thing is , I might end up with the same problems of corrosive fouling with decomposition of AP instead of PP.... Nh4 chloride and HCl, not sure.
The decomposition of AP is a little involved.
AN might be better in this regard, but its hygroscopic and dont know of any formulation to mitigate this effect.

residue

BPS - 21-8-2017 at 07:14

Just found this doc.
It would appear that almost all the C is left unchanged in the residue.
Though this needs to be looked into........ "In the presence of carbon, the reaction is complete above 240"C, the residue
consisting of carbon only (except, of course, in those runs in which explosion
occurred-see fig. 4)".
How the perchloric acid reacts, combined with water in the atmosphere, in a gun barrel, is anybodies guess at this point.



Attachment: AP C.pdf (658kB)
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physics inclination - 22-8-2017 at 14:16

Yea I guess one problem with chlorates in general, for implementation as a gun propellant, is that most all chlorine salts would be corrosive.
I wonder if ammonium nitrate could have performance like ammonium (per)chlorate, or whether AN would be too explosive for propellant purposes.

Fulmen - 22-8-2017 at 14:23

AN has excellent performance as a propellant, but limited usefulness as it's hygroscopic and undergoes phase changes that can cause grains to crumble/crack. Do a search for ammonpulver and phase stabilized AN.

XeonTheMGPony - 22-8-2017 at 14:39

Durring WW2 the German Wehrmacht Tried doing that with 95/5 AN/C, How ever as stated its tendency to recrystallize randomly caused burst barrels they switched to using it as a bursting charge Vs propellant.

Perchlorates = Rust + rust + even more rust!!

Metacelsus - 22-8-2017 at 17:55

Quote: Originally posted by Fulmen  
undergoes phase changes that can cause grains to crumble/crack


Interesting fact: this is what caused the notorious airbag explosions a few years ago. Manufacturers switched to cheaper ammonium nitrate, but didn't properly test the stability.

Bert - 29-8-2017 at 20:22

Quote: Originally posted by physics inclination  
Yea I guess one problem with chlorates in general, for implementation as a gun propellant, is that most all chlorine salts would be corrosive.
I wonder if ammonium nitrate could have performance like ammonium (per)chlorate, or whether AN would be too explosive for propellant purposes.


Chlorate propellants have a history of showing a rather more immediate problem than corrosion... Blowing up the gun or rocket motor. Seriously. 200+ years of explosives engineering has not yielded propellants using chlorate both superior to other salts AND safe enough for commercial and military use. But bursting charge and high explosives uses a-plenty.

.Perhaps keep any experiments small and well baricaded?

AP and AN both can function as either high explosives or oxidizers in propellant mixtures. Particle size and mixture are critical. Pure AP below 15 micron particle size is classed as a 1.1 explosive in transport.