Source is YouTube and Institute of Chemistry and Chemical Technology SB RAS (PDF). If you have 2 kilowatts, a coil of copper pipe, and a lot of guts, you too could melt aluminum with induction heating while it’s levitating.
Aww, I wanted to see it splat into the floor when they turn off the induction coil…
I always thought it fell when it got so hot that it lost its magnetism I’m sure I have read that metals do that at too high temperatures
I believe it’s suspended by eddy currents, not magnetism. Aluminum is a non-magnetic metal.
Thanks! What’s the difference?
eli5 - basically all materials have spins (As in electron spins), and magnetism is basically these tiny spins in materials, if paired - diamagnetism (all materials have this), paramagnetism (if you have unpaired electrons), and ferromagnetism (for now consider it special case of para). When heated up beyond curie temperature, ferro becomes para (kinda like fall back). Almost all metals are either para or ferro.
Now all materials kinda resist getting their state changed (there are 3 “energies” at play - exchange energies of electrons (consider the friendship force between electrons), electrons and external field, and the temperature “energy” (there is no real temp energy, but there is something like energy in form of k_B T, but that is not for now)). eddy current is basically manifestation of this (consider it like resistance to change of magnetisation by external field, by creating a field in opposite direction).
Indeed.
Despite my own work in making knives and other blacksmithing things, where I LITERALLY have a magnet on my anvil so I can test for when the steel hits it’s austenitic temp, I somehow managed to forget the iron will go non magnetic…
So yeah. Thanks for the reminder!
In my defense I haven’t made any knives since moving a year ago…
However, this is aluminum I think? I’m not entirely sure how magnetism works with lenzs law and if there’s a temperature it stops working…
It’s a handy principle. That’s how rice cookers work. Once the water has been soaked into the rice and the rest has evaporated, the metal insert will increase in temperature until the magnet no longer holds it down.
Ha! I always wondered how that worked! Lemmy comment section for the win!
FYI, you can see that in the source, which is linked in the description.
