Re: [FEMM] alnico5 versus ceramic5 ?

[Keith Gregory <K.Gregory@xxxxxxxxxxx>]

Bengt,

Alnico 5 and Ceramic 5 are entirely different materials. Alnico is an
aluminium-nickel-cobalt alloy (one of the earliest real permanent magnet
materials) and doesn't have a particularly big coercive force (I think
alnico5 in Femm has Hc of about 50,000A/m), will operate at up to about
1.2 Tesla and is electrically conductive. Ceramic 5 is a hard ferrite
made from stuff like Barium and Strontium (I will admit I don't know
exactly) and has a coercive force about four times that of alnico; it
will operate only up to about 0.4T but is non-conductive.

You will get a dramatic difference between the two materials in most
applications.

Keith.

 At 23:40 25/01/2004, you wrote:
> Hello.
> I wanna start with the fact that I realy like this program. I have had a
> lot of use for it when simulating magnetic structures for a ribbon
> speaker (tweeter). I have used the "Alnico5" too work as a
> ferritmagnet when I didn't find one in the library (didn't look at the
> bottom). Now I have found it and I was very surprised that the magnetic
> force increased when I replased the alnico5 with the
> "ceramic5". 
>  
> I'm using version3.3 build 30/3-03
>  
> Best regards. Dahlberg
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