Achilles - 15-10-2023 at 12:20
i tried to make a thermite cutter with Fe2O3/Al/S/Ba(NO3)2
the thermate composition without the binder..
the problem are 2:
-the first is that my Al powder are too small 9 micron, it burns too fast but when compressed the burning speed decreases (weirdly) but not enough..
so i need to know the best aluminum size
-the second problem is that to make the pressure build up i drilled a hole into the mix like in a rocket motor and i actually managed to cut a 2mm
steel plate but not thick steel.. i tried to put a nozzle of different sized but solid products closes the nozzle and it ends exploding…
the mix is also very heat sensitive even to a firecracker fuze due the aluminum small particles.. even if u take out the barium nitrate and sulfur it
still very heat sensitive to be a thermite never needed a magnesium/KMnO4 glycerin booster
so.. any suggestions?
[Edited on 15-10-2023 by Achilles]
Rainwater - 15-10-2023 at 14:08
A little oil mixed in with the aluminium should help slow the reaction. Never tried cutting with it, just welding.
If thats unacceptable maybe sintering the aluminium at around 500c then regrinding back into a powder
metalresearcher - 30-10-2023 at 11:14
I had no problems with this mixture. I mixed 69% generic thermite (3 parts Fe2O3 + 1 part Al powder) with 29% Ba(NO3)2 and 2% S. I could ignite it
with a small pile of KClO3 + sugar on top of it ignited just by a lighter.
It is much faster than generic thermite and the iron is released in very small balls rather than blobs.
I tried again with 54% generic thermite, 26% KNO3 and 2% S. Just another nitrate which also burns very fast and blindingly bright and hot (yes, dark
goggles needed), but it required some extra Al powder with the chlorate and sugar as a two factor ignition, like generic thermite.
Weird, barium nitrate presuably requires a lower ignition temperature than KNO3 (which is also a nitrate ?).