Warning: Thermite reactions produce high temperatures and flying bits of molten metal.
Fire safety protocols must be in place.
Greetings fellow nerds.
In a previous video i destroyed an aluminum bat with gallium metal.
I had a lot of requests for further experiments and one interesting one was to try and make thermite from the resulting soft aluminum.
To save you time i'll tell you upfront it failed miserably.
But if you want to know how and why it failed keep watching.
Now as you know thermite is a famous incendiary mixture made from aluminum metal and iron oxide.
Now iron oxide powder can be made by various chemicals processes as i've shown in a previous video.
But aluminum powder must be bought or filed off a piece of bulk aluminum.
The gallium I showed in a previous video can destroy aluminum
so maybe this material being very weak would be easier to make thermite from than filing bulk aluminum.
Now this gallium infused aluminum is crumbly, but it doesn't fall apart into a fine powder.
It breaks into chunks and but not smaller.
The cold gallium inside of it is still pretty strong when solid so it makes crushing the aluminum into smaller pieces very difficult.
To make it weak again we just warm it up to above the melting point of gallium.
This makes it considerably softer and we can crush it easily into much smaller pieces.
Okay i'm going to get about 25 grams of gallium infused aluminum to make our thermite.
I actually just need 20 grams of pure aluminum metal,
but i'm using some extra to account for the extra mass of gallium.
Now we just let that warm up and weaken to point that i can begin crushing it.
Now even though I can crush it i can't seem to get it into a fine powder.
A lot of the chunks are still too tough.
Even worse is that the molten gallium makes them aggregate back together again the more i work it.
We can encourage it to break apart by cooling it down.
Without molten gallium the pieces can't stick together.
The aggregates are considerably weaker so even though it's cold it's still easy to crush them.
Nonetheless the particles still aren't as fine as commercial aluminum powder and large uncrushable chunks remain.
Okay let me mix it in with 60 grams of laboratory grade iron oxide powder and mix it up thoroughly.
Then we transfer it to a clay pot.
Now let's begin testing.
As usual i'm using sparklers wrapped in magnesium ribbon.
And nothing happens.
Let me try again with another set of sparklers and ribbon.
And nothing happens there either.
The aluminum pieces are just too large to sustain a reaction.
This is a fail.
Now to make sure it's just particle size and not the gallium itself doing something
i'm going to get some of the gallium infused aluminum and file it down by hand.
We should be able to get fine aluminum powder this way.
This is going to take several hours to get the required 25 grams so i'm going to skip ahead.
And here is our mixture of filed down gallium infused aluminum thermite with 60 grams of iron oxide.
Looks like it works.
There is some unreacted material but that might be because my flower pot split before it could fully react.
So this goes to show you that using gallium to make bulk aluminum into aluminum powder is a bad idea.
The aluminum can be weakened and worked down into smaller pieces.
But the pieces don't get small enough to make good thermite.
Some of them simply don't break any smaller and the ones that do will aggregate again.
You can file it down, but if you're going to go through that trouble, just file down actual bulk aluminum.
Now get's go to the opposite end.
Instead of pure aluminum, let's try pure gallium thermite.
This is not as strange as it sounds, gallium and aluminum have very similar chemical properties
and gallium forms gallium oxide just like aluminum forms aluminum oxide.
So let's give it a try.
I have gallium and iron oxide and i've heated them both so the gallium will remain molten as i mix them.
I'm using 51g of gallium and 60 grams of iron oxide.
I'm using more gallium than aluminum in this mixture because gallium is much heavier than aluminum as an element
and so you need more gallium to match the stoichiometry.
Interestingly, gallium pools in the bottom of the iron oxide so you need to stir it up considerably for it to distribute throughout mixture.
It doesn't have nearly the same wetting properties as water does.
Eventually though, you'll have a mixture of gallium in iron oxide.
Interestingly enough the gallium is so finely mixed that you can't even see it.
But it's definitely in there.
In theory this should work awesomely well since we have a thin film of gallium on almost every iron oxide particle.
So let me try and ignite the mixture.
Well that was anticlimatic.
Let's seeů it melted together, so the heat was hot enough.
It just didn't sustain a reaction.
The reason why this didn't work is actually fundamental.
We can calculated the energy of the reaction through Hess's law.
Aluminum and iron oxide thermite liberates 851kJ/mol of energy.
This is a lot and goes into raising the temperature of the products to the point that the iron melts and can ignite the surrounding thermite.
The reaction is then self sustaining.
But with gallium and iron oxide thermite the energy release is 264.9kJ/mol.
Less than a third of the energy of aluminum.
This is not enough to initiate the surrounding thermite and the reaction stops.
Maybe we can get it to work if we had the thermite at an already high temperature, like a few hundred to several hundred degrees.
But that would defeat the purpose of thermite.
Ah well.
Gallium is hundred times more expensive than aluminum anyway.
Anyway, so there you have it.
We tried to use gallium to breakdown aluminum into something small enough to be useful for thermite but ultimately failed.
We also tried to use pure gallium itself as our thermite fuel
but that failed as well since gallium isn't energetic enough to sustain the reaction.
If you need aluminum powder buying it directly, or getting it the hard way through filing is still the best way.
Thanks for watching.
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