64 replies to this topic

[Mumbles]

I think he means for the testing why I am using Ammonium Perchlorate. I chose it because that is one the chemical dichromate still have problems with. Dichromate or linseed oil can both protect against water, and pretty much everything else. Ammonium Perchlorate is the one chem that can break through the protective layer I suppose. I can understand why. Most chromates and dichromates are insoluble in water. Ammonium Dichromate is soluble so it would have ease getting through. Ammonium Perchlorate is slightly acidic. I will be looking for a base reaction from the formation of Ammonia which is a sign of reaction with the oxide layer.

[BigG]

I think he means for the testing why I am using Ammonium Perchlorate. I chose it because that is one the chemical dichromate still have problems with. Dichromate or linseed oil can both protect against water, and pretty much everything else. Ammonium Perchlorate is the one chem that can break through the protective layer I suppose. I can understand why. Most chromates and dichromates are insoluble in water. Ammonium Dichromate is soluble so it would have ease getting through. Ammonium Perchlorate is slightly acidic. I will be looking for a base reaction from the formation of Ammonia which is a sign of reaction with the oxide layer.

I see - my only concern is that impurities of ammonium perchlorate render some compositions dangerous, so I was wondering whether this is a wise option to use if the magnesium is to be used in fireworks compositions.

[Mumbles]

For testing, it is just going to be Mg, and Ammonium Perchlorate solution. It is just stupid to use a composition for testing. You don't know what exactly is reacting, and the results could, and probably would be skewed.

Is there anything else you feel would be a better test for corrosion resistance for magnesium? I wanted to use a chemical found in fireworks. 1M HCl is not often found in fireworks you know. I thought maybe chloride, but without a microscope it could be hard to see. I think I will see about getting one anyway, so I can see what the surface looks like.

[completebeginner]

i was looking through the canadian tire catalog and found a magnesium bar for water heaters does anyone know if this stuff would be pure and if i were to grind magnesium and ball mill it would that be a good idea?

[warrenizer88]

Grinding metals in a ball mill is dangerous. It can be done, but there is a chance they will burn rapidly when the mill is opened due to the heat of an oxide layer forming on the particles. If i were you, i would not attempt it. It also takes a lot longer to grind a metal in a ball mill than a non-metal. This is because metal is ductile, so it does not break up like crystalline substances would.

[Mumbles]

I think malleable is the word you are looking for. It means it can bend and dent with out breaking. Ductile means you can draw it into wire. If you open the ball mill every few hours, the chances of it becoming pyrophoric greatly lowers.

Yes, sacraficial Mg anodes are fairly pure. At least technical grade I would say.

[completebeginner]

ok thank you i ordered one from homehardware itll be here in a week and thanks for the saftey tips

[warrenizer88]

Safety is the reason we're all here, and malleable was the word i was looking for. It was late at night and i couldnt remember which was which

[alany]

Grinding metals in a ball mill is dangerous. It can be done, but there is a chance they will burn rapidly when the mill is opened due to the heat of an oxide layer forming on the particles. If i were you, i would not attempt it. It also takes a lot longer to grind a metal in a ball mill than a non-metal. This is because metal is ductile, so it does not break up like crystalline substances would.

Pyrophoria is an over-exagerated hazard for the scale of milling and metals most amateurs are using. It is of course something to be careful about, but after doing the math I have serious doubts opening the jar every now and then is helpful in any significant way. I suspect stamp mills would actually be more effective in milling metals than ball mills, but they are noisy and more complex to build.

Almost all metals are crystaline BTW, some alloys are known to have the ability to remain amorphous if cooled sufficiently quickly but still slowly enough for objects of practical size to be made. In theory you can prepare any metal in an amorphous state, but it is nontrivial and impractical for most. Such "glassy" metals are of significant interest because they don't have grain, offering enhanced and isotropic mechanical properties.

Intermetallic compounds have very low ductility (generally, some "ductile intermetallics" have been discovered but they are rather exotic) and are the easiest alloys to powder for pyrotechnic use, hence my personal preference for Magnalium in homebrew milling. I have made very fine Magnesium without too much difficultly, it probably wasn't "micron-Magnesium", but it was frightfully reactive and not all that useful for my needs.

[completebeginner]

so i got my magnesium and made less than a gram of flash with course stuff that didnt even go through the ball mill and it worked magnificently! so i tried ball milling it this morning and i checked after 10 minutes because im impactient and to my surprise it was already fine and dull looking although there was no increased speed with the flash

Edit i tried milling it for an hour straight before making flash it turned an even darker grey and when the flash was made (next to none was used) instead of the normal flash it flashed and made a FOOP! sound

Edited by completebeginner, 18 October 2005 - 09:34 PM.

[Draco_Americanus]

E-bay is sometimes a good place to find Mg, sometimes even allready milled. I scored a 5 pound block for not a lot of money myself. Now I don't realy know what to do with it as a 5 pound block is rather large, maby I could use it as a door stop.

[paul]

Now I don't realy know what to do with it as a 5 pound block is rather large, maby I could use it as a door stop.

[completebeginner]

i was reading making and understanding exploding fireworks and saw that it said that if you ad a small amount of stearin or ivory soap that you dont have to open the milling jar regularly whilst making metal powders does anyone have any experience with this?

[GBthriller]

i was reading making and understanding exploding fireworks and saw that it said that if you ad a small amount of stearin or ivory soap that you dont have to open the milling jar regularly whilst making metal powders does anyone have any experience with this?

It would seem nobody has experience here.

I'm going to try ball-milling some fine flake alum with some fine stearin flakes thrown in to see what results; Hopefully some protection against H2O.

Will report here when its complete.

Q: Should I do the same with some Mag. shavings?? Can anyone foresee any problems there?

[fishy1]

It would seem nobody has experience here.

I'm going to try ball-milling some fine flake alum with some fine stearin flakes thrown in to see what results; Hopefully some protection against H2O.

Will report here when its complete.

Q: Should I do the same with some Mag. shavings?? Can anyone foresee any problems there?

i've heard of magnesium powder igniting when the media was dropped on it.

don't know why, but it gives you nasty burns. open the jar regularly, and if the jar is very warm, take great care.