Coarse Aluminium

[Rkteer]

Hey guys,

 

I work in a machine shop mostly machining aluminium and stainless steel.

 

We have ALOT of aluminium swarf from many machine tools, it's coarse though.

Could I ball mill this aluminium for use in compositions?

In a separate jar with SS media?

The grade of alloy is 6061 t6 mostly.

[Zumber]

Sounds difficult.

You wont get superfine(extremely fine aluminium).

[schroedinger]

Sounds difficult.

You wont get superfine(extremely fine aluminium).

Thats wrong, you can even mill it down to dark flash grades.

The mill needs to be vented carefully every couple hours and you need to get rid of the oil, normally clingin to milling flakes.

You also could use to coarse stuff for firefly and similar thing or just melt it into mgal.

[Rkteer]

Yeah I plan to make mgal as well.

Where can I get cheap sources of magnesium though?

I was thinking maybe A motorbike wreckers for broken mg cases

[Mumbles]

Thats wrong, you can even mill it down to dark flash grades.

The mill needs to be vented carefully every couple hours and you need to get rid of the oil, normally clingin to milling flakes.

You also could use to coarse stuff for firefly and similar thing or just melt it into mgal.

 

Anything finer than about 100 mesh flake will make flash. That said I've never seen one verified case of anyone being able to approach single digit micron flake aluminum by ball milling at home, which is what you are implying. Since you seem to be confident that this is possible, could you please share a source?

 

Melting down turnings is difficult due to the springiness and high surface area. It's usually a good idea to add the turnings to a pool of already molten metal to cut down on oxidation and flare ups.

[Rkteer]

So will this milled aluminium milled down a bit be usefull for slow flash booster for shells?

I don't have access to perc being in Australia.

 

Would chlorate from a chlorate cell be better? I may make one in the near future.

[schroedinger]

Anything finer than about 100 mesh flake will make flash. That said I've never seen one verified case of anyone being able to approach single digit micron flake aluminum by ball milling at home, which is what you are implying. Since you seem to be confident that this is possible, could you please share a source?

 

Melting down turnings is difficult due to the springiness and high surface area. It's usually a good idea to add the turnings to a pool of already molten metal to cut down on oxidation and flare ups.

 

Mumbles a HF mill will create that type of powder. After 14 days it has the same size as black 000 undet a microscope. I will see if i canbfind the video where someone made a documention about the process taking samples every couple days/ hours. But for homemade process mgal is much more suited, it just brakes down a lot faster.

[FlaMtnBkr]

There is probably a better process for making aluminum powder if it isn't available to you. Milling chips are going to take a lot of extra work to break down.

 

Aluminum foil chopped in a blender with water breaks down a lot quicker since it's so thin to start. Once chopped up then into the mill.

 

And if you have access to a machine shop an even better use of it would be to make a simple machine. Something similar to a ball mill that turns a drum that dips down into a container containing either water or oil. The drum is then covered with wet/dry sanding paper and a chunk of aluminum is mounted to an arm that rotates down so the aluminum is ground down and can be moved around and adjusted as needed. There is also a place to add various amounts of weight to push the aluminum into the sanding drum. The water or oil catches the aluminum dust and traps it in a wet slurry. It also cools the metal and lubricates the paper so the grit lasts longer. The powder can then be further ball milled if you need it finer.

 

If you are thinking about turning metal into powder, make sure to look up the word pyrophoric and learn all the safety steps you need to take. Might be easier to ask some of the other aussies where to buy it.

 

You may also be able to buy bright flake aluminum that is also quite fine at a paint supply store and use as is or mill for a more dark like product.

[schroedinger]

FlatMtnBkr, skip that step with the sanding paper, it just gives you a whole lot of unknown impurities. A blender chops down aluminium foil to -500 mesh in a day.

[Mumbles]

Mumbles a HF mill will create that type of powder. After 14 days it has the same size as black 000 undet a microscope. I will see if i canbfind the video where someone made a documention about the process taking samples every couple days/ hours. But for homemade process mgal is much more suited, it just brakes down a lot faster.

 

 

No luck on this documentation I take it?

[OldMarine]

Here's a guy milling foil to a very fine mesh:

https://youtu.be/nA94uHqUQvg

[PhoenixRising]

In that video, the guy says he's using "steel" for his milling media? Please correct me if I'm wrong, but doesn't steel spark, and would that not be bad? Still haven't had any coffee this morning....

[lloyd]

There are two things going in his favor, Phoenix:

 

1) That's a LITTLE jar, so the media doesn't have very far to fall -- much less energy imparted to the media means much less tendency to spark. He's also vastly under-charging it with media, so there're even fewer impacts to be concerned with.

 

2) The only oxidizer in that jar is air, and the O2 from it gets depleted VERY rapidly as freshly-exposed aluminum oxidizes. Likely inside of ten minutes, most of the O2 is used up.

 

His process would go a lot faster if he'd use a bigger jar, charge it properly with spherical or cylindrical media, run it at the correct rate, prep his material separately, rather than slowly adding stock over days... He could probably reduce that ten days of milling to about two days.

 

He DOES need the hardness AND mass of stainless steel media. Lead is too soft for this work, and ceramics too light.

 

Lloyd

[PhoenixRising]

Thanks for the info Lloyd, I always assumed doing this would be very bad. I'll most likely continue to buy my Aluminum for some time to come, but it's certainly good theory for getting my feet wet if I choose to pursue it later.

 

This thread is a good reminder for me to update my milling media as well. I only mill BP and likes 100 g's at a time so I just use lead sinkers for now. The results are 'good enough', but I think the oddball shape is going to cause them to wear out faster.

Edited May 5, 2016 by PhoenixRising

[schroedinger]

No luck on this documentation I take it?

 

No, didn't find it. Just found the vid by dornier 335a, where he grinds al between two steel plates, but thats quite impractical.

[Rkteer]

Would this powder be usable for a slow flash shell boost?

http://www.rungoodlabs.com/store/p43/Aluminium_Powder_(45_micron).html?Weight+(g)=100

[FlaMtnBkr]

It will likely speed things up a bit just from the extra heat. But that isn't the best aluminum and is pretty expensive. But if you're in a country where things are hard to find that may be an appropriate price.

 

Have you checked a commercial paint store (not just house paint) to see what they have? You should be able to find bright flake that is smaller than 300 mesh and, obviously, flake instead of atomized. Most silver plastic electronics like some computer cases use this type aluminum. Like this:

 

http://images.geeksimages.com/imageshare/C/300x300/CS51WSL-unit.jpg

[dagabu]

I have made a lot of usable aluminum flake (100 mesh plus+) from swarf but you do need to do as Lloyd says and get past the springiness of the curls. I found a simple press or a sledge hammer to accomplish this. Just squish it flat! Stainless steel rods also work well to get it to crush quickly and using a PVC jar, I wasn't afraid of the damage as it was just drain pipe and easy to replace.

 

I did find that a nitrogen or CO2 purge of the jar helped a lot with the resulting powder heating up when the milling was over and a simple teaspoon of Stearic Acid (DUDA Diesel has an 8oz bag for $2.50!) added to the jar when starting coats all of the newly formed surfaces well enough to keep it from "flash oxidizing" when opening the jar.

 

We are only a tiny segment of people that use finely divided aluminum, there are lots of others out there with more experience than I, do a google/bing search for more information.

[Rkteer]

Hey guys I've been away from home for a bit, back now.

 

So if I ball mill the atomised 200 mesh AL will I get a usable flake for a booster?

 

I have called a few paint places and only flake I have been able to get onto was 80 dollars for 300 grams!

 

I have also gotten onto a place that sells 10 micron flake but it's 80 dollars for 1kg.

 

I'm from Australia if anyone has a source they wouldn't mind sharing for flake AL.

[CrossOut]

I spoke with a guy that said he produced his own AL powder fine enough for flash. He made a conveyor belt from a type writer ribbon and set a block of aluminum on top with weight to slowly grind away. The belt passes through water to wash out the aluminum and catch the powder. I haven't tested this method but it's sounds reasonable. And I consider him a very reliable source.

[Rkteer]

Sounds interesting.

I might make something along the lines for this

Can 200 mesh atomised AL be called milled for a flake product?

[CrossOut]

in theory yes.. ive had very little success doing so.. atomized AL aka Spherical aluminum is pretty tough stuff.. as we know spheres are very strong structurally. so the best way to reduce it is with some sort of grinding motion.. ball mills actually work by more by crushing than grinding so its not very effective. I would recommend smelting some 50 50 MGAL and reducing that using a ball mill. that stuff reduces super quick and has tons of uses...

 

That said i need to stress Using a separate Mill / Media for metals only i have stuff set aside only for use with MGAL.

Edited June 17, 2016 by CrossOut

[Rkteer]

Hey thanks for the reply.

Bugger that it's hard to do. Would be nice because I can get atomised AL for 20/kg

I'm also thinking of making some mgal and just using that. Seems to be the easiest way.

 

Just have to get onto some mg

I do have some but always want more!

[CrossOut]

If you plan on smelting your mg, go to junk yards and try salvaging broken magnesium transmissions or wheel rims. You can cut them down to more manageable sizes and is usually a super cheap source.

[MrB]

If you plan on smelting your mg, go to junk yards and try salvaging broken magnesium transmissions or wheel rims. You can cut them down to more manageable sizes and is usually a super cheap source.

 

That is what i do, but it's sort of a bother. You need to identify what your actually getting, and the alloy isn't always obvious. And when it is, it usually turns out you get to much aluminum, and not enough magnesium for your preferred end result. So you still need to obtain, and add some pure mg if your looking for a specific end result.

 

Not to mention that a lot of junkyards around here know exactly what your picking, and mg isn't something they let go cheap, even if it's alloyed like this.

B!