[modeleng] Re: O/T. Dust iron cores

Hi Alan and Clif,

If you mean ferrites, they are made by powder metallurgy (PM).

Iron and other metals are first powdered by breaking up a stream of molten 
metal with compressed air. A die is made and the powder loaded into it. The 
powder is compressed in the die in a press with several thousand tons 
pressure with a punch from either side. Parts are ejected and then placed in 
a sintering furnace, where they are heated at temp sufficient to cause 
fusing of the particles.

Oilite bearings are made exactly the same way, only with larger particles 
with bigger inter-particle gaps to allow oil to be impregnated after 
sintering and cooling under vacuum.

Many gears and levers in appliances and cars are made with the PM process 
also.

I regularly designed and programmed the machining of PM dies and punches 
when I worked at Honeywell. They used PM gears extensively on gearmotors for 
operating steam and hot water valves, and at one time made ferrites for 
their electronics products.

Cheers Jeff Dayman


>From: <clif.gwr@xxxxxxxxxxxx>
>Reply-To: modeleng@xxxxxxxxxxxxx
>To: <modeleng@xxxxxxxxxxxxx>
>Subject: [modeleng] Re: O/T. Dust iron cores
>Date: Mon, 10 Mar 2008 10:32:55 -0000
>
>Hi Alan,
>
>I would assume that they are mixed with some sort of glue, heated and fused
>together.
>I seem to recollect that when I played with electronics years ago they were
>very brittle.
>
>Regards
>
>Clif
>----- Original Message -----
>From: "Alan Stepney" <alan@xxxxxxxxxxxxxxxx>
>To: <modeleng@xxxxxxxxxxxxx>
>Sent: Monday, March 10, 2008 10:01 AM
>Subject: [modeleng] O/T. Dust iron cores
>
>
> > Anyone who has played around with radio or electronics, will know of 
>dust
> > iron cores, used in inductors.
> >
> > How are they made?
> >
> >
> > http://www.alanstepney.info
> > Alan Stepney's Model Engineering, steam, and workshop pages.
> >
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