I've been eyeballing that big chunk of Micrometals iron for quite a while now,..mentioned it earlier.
#40 mix is the part that stops me. I looked up the web site, and they have all the mix's and properties listed.
Page down a little, and theres a nice general description of uses for the various mix's.
Micrometals; https://www.micrometals.com/materials/pc
I don't think the particles in this block are particularly insulated, but it would be interesting to see how the mill chews
it up, or if it can be easily cut, or how strong it is. At any rate, the price is right!!
The powdered iron you show is what I bought for my 'experimental core' back at the very beginning of this thread, and I
used resin for a binder. But it needs to also be under great pressure, I think, and each partial should be insulated for best
results.
Which is why I thought the oxide and phosphate insulation was interesting,.. rust is easy, and phosphate is cheap.
I dip bike frames in a large tank of it, before I spray primer on them. Will also act as a rust remover, if left in longer.
Oxidation is like anodizing, I think, and is non-conductive. The phosphate just keeps it from rusting any farther.
Another way to do it, is to swirl the powder in a chamber of paint, as damirski showed a few pages back.
According to Wikipedia, annealing the iron before use will also reduce hysteresis, So maybe with all of this new info.
the experiment could be tried again.
Supposedly, thats what Somaloy is,.. coated particles, compressed and heated, and made for cheap motor cores. Exactly
what we need, as it can be cut, and machined,without too much difficulty, except for some crumbling of the edges.
Somaloy; https://docplayer.net/20823110-Iron-core-material-somaloy-unique-magnetic-properties-high-purity-iron-powder-electrically-insulated-surface-result-in.html
Only problem is availability for poor shop rats like us. I can't find any retail outlets, other than a machine shop that has
scrap piles of it, and even that lead was out of date. But perhaps some more digging would turn something up.
No large motors using it, but still maybe better than air core? it doesn't weigh as much as laminations, and is moldable,
which is a BIG plus with a new design. Coil cores have been a knife in my side since the beginning, it would be nice to find
a usable solution.