Amorphous iron UMCCC-125: what would you do from it?

[Wavebourn]

Let's dream a bit...

http://e-news.bfioptilas.com/e_news/...tsamorphes.pdf

[alexberg]

Originally Posted by Wavebourn

Let's dream a bit...

http://e-news.bfioptilas.com/e_news/...tsamorphes.pdf

So what?
a) poor filling factor,
b) lower saturation flux density,
c) low losses - high Q resonances
d) pricey - about $15-30 per kg
e) cast in China, annealed in India
f) grainy cut - no small gaps
etc.
If this is O'K with you - just get another C-set and make EE core and, eventally, the transformer you may or may not like.
Nanoperm and the likes are much better
Other then that - just another core material, potentially used by some audio transformers manufacturers.
The latter may not be applicable for this particular core just because quite a few amorphous/nanocrystal alloys may be used
BTW Metglas samples up to 5 cores for free
P.S. Using amorph for 20+ years for SMPS magnetics.

[pieter t]

Anatoliy,

This is what I use for my amorphous core transformers, mostly in double c (two cores; one coil).
Maybe when Alexberg has the same over ten years experience which I have using these cores for audio transformers he will know what he is talking about; amorphous cores for SMPS is a quite different application.
Amorphous cores for audio transformers were first used by Tamura in Japan, I was the first using them outside Japan (Tribute Audio Transformers).
If you look for a less colored sound and excellent transparency, these transformers will deliver; many tube guys will confirm that.
Apart from that, especially for push-pull output transformers this material is inherently superior to any grade of silicon steel because of it's better hysteresis properties.
However there might be some difference in quality with cores from different manufacturers; I use the originall stuff, developed by Allied Signal / Metglas; factory is in India (these cores have the AMCC typo).
I don't know where your UMCC is coming from; there seem to be more companies using the basic Metglas amorphous tape.
The Chinese made their copies, you guess the CMCC range, but less in quality.

[alexberg]

Absolutely,
audio transformer is a different beast... but we're talking about the cores.
I've intentionally tried not to touch "audio specific" considerations...
Alex
P.S. I'm using FT-3L Hitachi_Metglas, not amorph, for audio, as DIYer...

[pieter t]

Originally Posted by alexberg

P.S. I'm using FT-3L Hitachi_Metglas, not amorph, for audio, as DIYer...

Alex, look at Finemet FT-3L data and the way this material is manufactured, and then repeat that it is not amorphous....

[LinuksGuru]

From the Hitachi brochure:

The amorphous ribbon is the precursor material of FINEMET®. This ribbon, “which is about 18 μm in thickness”, is cast by rapid quenching, called “single roll method”, then the amorphous ribbon is wound into a toroidal core. Finally, the heat treatment is applied to the core for crystallization in order to obtain excellent soft magnetic properties of FINEMET®.

The core loss of FINEMET® (FT-3M) cut core has less than 1/5th the core loss of Fe based amorphous metal and Mn-Zn ferrite, and less than 1/10th the core loss of silicon steel at 10kHz, Bm=0.2T. FINEMET® has significantly lower core loss and thus makes it possible to reduce the size of the core for high frequency power transformer. Also, the magnetostriction of FT-3M is 10-7 order and, as a result, cores made from this material will make very little audible noise when compared to cut cores made from Fe based amorphous metal and silicon steel.

Hitachi defines Finemet as nanocrystalline alloy made from amorphous ribbon.

[pieter t]

Originally Posted by LinuksGuru

Hitachi defines Finemet as nanocrystalline alloy made from amorphous ribbon.

Thanks Linuksguru, that's what I meant

[alexberg]

Originally Posted by pieter t

Alex, look at Finemet FT-3L data and the way this material is manufactured, and then repeat that it is not amorphous....

That's the easy one
"look at Finemet FT-3L data", pieter t
I do repeat that after annealing FT-3L becomes polycrystalline with particular crystal size and not the glass-like material.
By your logic we shall call ordinary steel resolidified but still "MOLTEN"
In contrary steels can grain oriented, non grain oriented, high Si, ultra high Si
and nobody mix one with the other due to huge difference in properties.

P.S. Stupid me!
I've thought that guru (mass production specialist) with 10+ years of experience would give some intricacies of material advantages utilization. Instead we discussing "how many enemies of mankind can sit on the tip of the needle simultaneously"

[pieter t]

Alex,
I looked at Finemet data.
You are completely right, as the amorphous material is annealed, becoming nano-crystalline.
This material is presented as "nanocrystalline amorphous", but once more, fundamentally you are right.
Silicon steel already has a crystalline structure when processed; properties of this material can be improved by annealing (grain orientation).
Nano-crystallization is only possible with the "precursor material being amorphous".
Do me a favour: don't call me a guru, I hate that term. I merely try to wind quality transformers through experience and craftsmanship; no voodoo, but trying to take advantage of the core materials available nowadays.
Anatoliy, why don't you pop in here? I have no bad feelings.

[Wavebourn]

Originally Posted by alexberg

BTW Metglas samples up to 5 cores for free

Here is the answer I got today:

Hello Anatoliy,



Thank you for your interest in Metglas AMCC-125 cores.



I anticipate that the AMCC-125 core can be utilized in your application.



The AMCC-125 is not supplied as a ‘free’ sample. These cores can be acquired through our distributor, Elna Magnetics.