Moldable Iron Powder

Interesting! What is it called, and is there a web reference?

Searching on "magnetic paint" on the Home Depot or Rust-Oleum sites
should get you there.

--
www.wescottdesign.com

Tim Wescott wrote:

It's either soft iron, or it needs a strong field to polarize it. How is
it used? (IIRC, the permeability of ceramic magnets id low, so they
support large gaps too.)

Jerry
--
Engineering is the art of making what you want from things you can get.
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Jerry Avins wrote:

 From what I found searching, it's soft. that is, magnets are attracted
to it, but it's not attractive on its own.

Jerry
--
Engineering is the art of making what you want from things you can get.
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On Mon, 23 Nov 2009 17:50:19 -0500, Jerry Avins wrote:


Right.  I'm looking for an armature material for an oddball electromagnet
-- big, light (well, relatively), and capable of supporting a significant
AC component without wasting it all as heat.

--
www.wescottdesign.com

Don't know about the power, but I've used these
people for sample cores.  Fast service and good
product.  They might be able to find you some
powder.

https://www.amidoncorp.com/

Hi Tim,
There are a lot of iron filled epoxies out there. Two names that come to
mind immediately are Moglice and Devcon. I recall Dave Trumper at MIT
had a nice mag-lev demo that used a photocell as feedback.

--
Jeff Lowe

TTim Wescott wrote:

On Mon, 23 Nov 2009 14:52:16 -0500, jeff wrote:


Thanks Jeff.  That gave me the keywords I needed.

Goodness but it's expensive stuff, at least from McMaster.  Gotta think
about this again, maybe.

--
www.wescottdesign.com

wrote:


Might try picking these up, too:

http://dspace.mit.edu/bitstream/handle/1721.1/13582/24130470.pdf?sequence=1
http://dspace.mit.edu/bitstream/handle/1721.1/29730/54039899.pdf?sequence=1

PDF files worth reading.  (Found them using David's name, above.)

Jon

Look for sintered metal in a magnetic material.  I think some magnets are
made with sintered iron.

On Sun, 29 Nov 2009 16:06:49 -0800, Jon Kirwan


I wish this had come up 5 months ago, when I was taking down Ceromet/MPP
in Anaheim, California.

I could have gotten you guys a few thousand pounds of iron powder for
free.  

http://metalpowderproducts.com/


If you want a few pounds..maybe I can get it from another company if I
ask nice and they want a service call.....

http://www.capstan.cc/locs-cal.htm

Gunner

"Aren't cats Libertarian? They just want to be left alone.
I think our dog is a Democrat, as he is always looking for a handout"
                                     Unknown Usnet Poster

Heh, heh, I'm pretty sure my dog is a liberal - he has no balls.
                                         Keyton

I've often wished that someone would make enameled soft iron "winding" wire.
Then I could
reverse the process - make up an arbitrarily complex winding on a simple bobbin,
then wind
the iron onto the copper "toroid" (all in a single pass of course).
Tony

Tony wrote:

Then I could

bobbin, then wind

Why enameled? The black oxide on soft-annealed iron wire is usually
sufficient insulation to suppress eddy currents.

Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

Jerry Avins wrote:

Annealed oxide-coated iron wire is used by jewelers to hold assemblies
together for soldering. Solder won't flow on it.
https://eclient.ijsinc.com/eshop/default.aspx

Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

Tim Wescott wrote:

How about a ping-pong ball into a chemical silvering mirror solution and
then electroplate iron onto it in a simple ferrous plating bath?

Yes. Although the raw material when dry requires a bit of careful
handling preferably in an inert atmosphere. Finely divided iron powder
intended for magnetic crack detection is usually supplied as a
suspension mixed in kerosene. In the air as a dust it can be pyrophoric.

It is fun to paint some on a magnetic card strip you no longer need.

You might be better off with finely ground magnetite. That is easier to
handle and doesn't go woof. This stuff is in vogue these days for fancy
magnetoresponsive goops in various esoteric devices. You can make it do
some of the T2 type flow then rigid things with a bit of effort - except
it is dirty black gunge and gets everywhere instead of a nice mirror
finish like in the movie... and a bit fanciful in some articles by the
proponents of the technology. eg

http://science.howstuffworks.com/liquid-body-armor2.htm

Someone like Alfa or an NDT specialist supplier will sell you the stuff
but whether you will think the price is reasonable is harder to answer.

Regards,
Martin Brown

I dunno about the ability to meet your requirements, but there are iron
powders available for various uses, from toys (Etch-A-Sketch), to industrial
uses.. electromagnetic clutches/brakes for machines.
These examples are moderately coarse powders.

Very fine iron/steel particles are a byproduct of etching/cleaning or
pickling steel products in manufacturing. The steel parts are pickled in
various acids, and the particles which are suspended in the liquids are then
filtered to remove the particles from the acids. The result is a
mud/clay-like material that is used to manufacture other products, including
iron composition cores for certain magnetic properties.

I don't have any sources to recommend.

--
WB
.........
metalworking projects
www.kwagmire.com/metal_proj.html

The finest iron powders are called "carbonyl iron"
(http://en.wikipedia.org/wiki/Carbonyl_iron ).  

Googling for carbonyl iron brought up this supplier:
<http://www.chemicalstore.com/navigation/detail.asp?id=IRON100> .

Joe Gwinn

Wild_Bill wrote:

Many years ago, the ferrite factory for which I worked used oxide from
the steel mills as a raw material. I was told there were mountains of
the stuff in West Virginia.
To be usable for magnetics, the oxide would have to be fired in a cycle
that included high temperatures and witchcraft.

Kevin Gallimore

Zone refine.  Melted in a magnetic field and the field is moved
slowly towards an end - moving impurities with it.

Expensive refining but quality product.
Similar to that of a semiconductor process.
Likely from the ferrite business.

Martin

axolotl wrote: