Thermite and Magnets

[mongo blongo]

I have an idea about the use of magnets in conjunction with thermite to increase the efficiency of the incendiary when the target is made of an easily magnetized material like steel.
What I propose is using Al/FeO3 thermite binded with hydrated calcium sulfate in an amount of about 5 to 10%.
When molding, a powerful neodymium magnet is imbedded in the block of thermite close to the surface of the block.
When placing the thermite block on the target it will conveniently stick to the surface of the target. This is just a bonus to the idea I have.
When the magnet is in close proximity to the metal surface of the target, the target will itself be magnetized.
The thermite charge is then ignited. When the molten iron is produced from the reaction it will instantly be attracted to the magnetized target.
When holes have been made from the drops of molten iron, the iron will cling to the sides of the hole instead of falling through. This will obviously increase the damage effects of the incendiary device.
When a big enough hole is made, the molten iron will fall through but this is good if you want to damage something inside the target like the engine of a car. This will also happen when the magnet is destroyed.
This will also be good for placing charges on horizontal surfaces since gravity is not as much of a problem to the molten iron.
Any comments on this?

[xoo1246]

Comment, heat affects the magnet, destroying it's magnetic propperties, if I remember it correctly. If I'm wrong, it could be an idea worth a try.

[A-BOMB]

That correct Zoo extreme heat and repeated shocks(hitting it with hammer) will demagnitize a magenet.

[vulture]

Xoo, you're right. Magnet's show their magnetic properties thanks to the valence electron spin which all have the same orientation. When heated, those electrons start to move randomly and the orientation and thus the magnetizing effect is lost.

[mongo blongo]

I meant placing the magnet so that it is last to be destroyed.

[inferno]

If the magnet is anywhere near 3000*C molten iron, its going to stuff up....good idea but i don't think it will work. Magnets do lose their magnestism at extreme temperatures, and 3000C is about as extreme as you can get (without industrial machines), so it will melt and/or lose its magnetism long before it can make anything cling to a surface.

[Jhonbus]

The fact of the magnet heating up and becoming demagnetised is only a secondary problem; the primary one being that even assuming it still *is* a magnet, it won't attract molten iron in the first place.

<small>[ August 24, 2002, 09:37 PM: Message edited by: Jhonbus ]</small>

[kingspaz]

due to molten iron having no crystal structure and megnetism being attributed to crystal structure.

[Energy84]

Molten iron IS attracted to magnets. I have witnessed it first hand while welding near a large (2 sq ft) magnet. It's a bitch to weld when all of your welds are being attracted to the magnet.
Since the magnet would however be destroyed in the process of being heated like that, could an electromagnet be used instead? Of course, it would have to be placed some distance away from the charge, but this shouldn't be a problem if it's powerful enough.

[rikkitikkitavi]

Energy 84, did you use a arc welder?

If so , the reason why the molten iron was attracted to the magnet was probably because of the high currents running through it were creating a strong magnetic field attracting it to the magnet. This is a common problem in arc welding, especially when you use magnets to clamp the two steel items to be welded together.

anyway, permanent magnets of any kind loose their magnetic properties at a specific temperature, often within a few degrees C, . Its called the Curie point. The better the magnet the more sensitive, neodymmagnets have a Curiepoint of 310-350 C, depending on composition. Samariummagnets have a Curiepoint of 800-900 C depening on composition, but are much more expensive.

/rickard

[Energy84]

Yeah, it was an arc welder. Heh, you learn something new every day eh? :cool:
Hmmm, so I guess electromagnetism is out to then right? That sucks.
Good thinkin' anyways Mongo Blongo. :)

[mongo blongo]

Arse!! I forgot about molten iron having no crystal structure when molten!!. There is nothing I can think of anything to rectify this!! Sorry I should have thought harder before I posted this! <img border="0" title="" alt="[Frown]" src="frown.gif" />

[kanbayat]

it was a good idea with the magnet..but duct tape would work as well on a horizontial target. gravity will take the molton material down into the engine compartment..and if youre lucky..the heat will ignite any fuel present anyway and rend the vehicle into a flaming specticle as well.
In the service we used aluminum tubing as a container..mag would be better ..but in an improv situation..aluminum burns nicely.
The thermite charges the military supplied us with..paled in comparison with what we came up with in aussie during the vietnam conflict. we used black iron..the military stuff used a mix of red and black..not as effective in my oppinion.
peace..ppl

[the resourceless reaperman]

I may have misunderstood but isn't the thermite supposed in this case to be Fe2O3? because FeO3 doesn't exist I did hear of FeO2 or even FeO but those wouldn't work.

by the way why not just put your container on top of the car, it'd burn through the car that way :D

<small>[ October 11, 2002, 09:54 AM: Message edited by: the resourceless reaperman ]</small>

[Marvin]

Thermite is a mixture. The iron oxide in thermite is often Fe2O3, but there are a lot of iron oxides.

Elements arnt restricted to just having 2 oxidation states. Iron forms compounds in which it has oxidation states of 0, +2, +3, +4, +6, and those are just the common ones. Its normal to think about iron only having oxidation states of 0, +2 and +3. But then its also normal to assume chlorine only does 0, and -1.

[the resourceless reaperman]

what do those molecules look like? And shouldn't Fe?O8 be possible?

[Atra]

Can't Fe3O4(magnetite) be used for thermite its highly ferromagnetic and that way would be attracted to where you wish it to go before it heats up.

However molten iron should still be attracted crystal structure or no it just can't hold a magnetic field. Much like a ferrofluid it can be magnetized but when the field is removed it goes goes away. 2 ideas for the magnet first neodynium has one of the lowest curie temperatures of any type of magnet samarium cobalt magnets are much hardier.

However your best idea was the electromagnet. If you could find some way of a second device also hitting the target and magnetizing a piece of it temporarily that would keep the thermite there. The only problem is this would be easily defeatable by lowering the electrical conductivity and or ferromagnetic properties of the material the target is made of.

[dana_m_h]

Another thing about iron around magnets is that it has a tendency to block magnetic fields. It redirects the lines of magnetic flux. Soft iron is used to sheild compasses and sensitive electronic circuits when they will be exposed to extreme magnetic fields. So the thermite you are using might absorb the magnetic fields remdering the magnet inside ineffective.

[Jacks Complete]

Without a low conductivity thermal shield good to very high temperatures, this isn't going to work, as the melting point of steel is well above the curie point of that steel. The way to tell that steel in a forge is ready to be hammered is that it will no longer be attracted to a magnet, and that happens at the bright red stage.

Fancy magnets might work, but certainly none of the high-powered ceramic ones, as they are all killed utterly by heat. I fragged one from welding, and it is now only faintly magnetic. Further, the impact shock would kill it, even at really quite low speeds, because they shatter if allowed to slam together (don't forget it will accelerate dramatically towards the steel target once it gets close.) This impact will also fragment most ceramics that could survive the temperatures involved for even a short time.

Finally, thermite is *not* a anti-armour solution. It welds and messes things up, but it doesn't cut through anything thick. Use a shaped charge for that.

[defiant]

For the reasons stated above I don't think it would work either. Thermite reaches temperatures of 4500 degrees Farenheit.

US Patent 6,766,744 might be of interest though - its a directional thermite cutter charge:

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6766744.PN.&OS=PN/6766744&RS=PN/6766744

[Lewis]

Allthough molten iron itself may not be magnetic, the magnet idea doesn't necessarily have to be abandoned. It could be useful to fashion a sort of plunger device for cutting upwards or at odd angles.

Perhaps a clay or other thermally robust syringe could be filled with a thermite compound and aimed into to the surface that needed to be cut. The plunger of the syringe could be a thick iron plug designed not to completely melt.

A strong magnet could then be placed on the other side of whatever needed to be cut. Once the thermite was ignited, it would liquify, and flow through the choke at the end of the tube, propelled by the still solid iron plunger.

This is probably a needlessly complicated design; however, it is a feasible way to deliver a jet of thermite at odd angles by a simple mechanic process.

Just my two cents.

[Bert]

It would be simpler to mix a small percentage of Teflon powder with the thermite, see the US patent for "pyronol torch".

5,372,069 Pyronol torch

[nbk2000]

The thing with using teflon is that it can, in combination with metal powders, spontaneously ignite (explode, actually) during consolidation pressing. :(

[Lewis]

I'm confused. What is the teflon supposed to do in the mixture?

[nbk2000]

Binder and oxidizer.

[Bert]

It "pressurizes the effluent". It causes the molten steel to issue as a high pressure jet rather than just dribbling out. Straight thermites are typicaly nearly gasless reactions-