magnetic standards

Question

magnetic standards

isogen (Mechanical)

(OP)

16 Mar 09 19:35

Is there a committee that establishes standards for qualifications such as the N42 rating? Are they accessible for finding information that goes with a rating, such as the hysteresis curve for the mentioned N42 rating?

If there isn't any official body, where can I get a numerical listing of the data points of the hysteresis/demag curve for N42s? The best I was able to get from the manufacturer was a scanned in .jpg where I had to count pixels and interpolate the values.

MagMike (Materials) · Answer 1 · 2009-03-16 20:03:52

There is the International Magnetics Association at:
http://www.intl-magnetics.org/

But the grades of most magnetic materials, particularly fully sintered NdFeB are defined by their magnetic properties, not by committee.

Usually N42 means a fully sintered NdFeB material with nergy product of 42 MGOe. Assuming you are dealing with room temperature properties and the material has a reasonable intrinsic coercivity, the hysteresis/demag curve will be a straight line and you'll just need two points to completely describe the magnetic properties.

N42 material will have a remanence of 13100 Gauss and the (normal) coercivity will be 12500 Oersted. If you need curves for higher temperatures, find a more reputable vendor or post here with the temperatures of interest.

MJR2 (Mechanical) · Answer 2 · 2009-03-17 07:44:10

One of my qualifications of a vendor is if they can provide a decent B-H curve with temperatures. If they ask me what that is we do not need to continue the conversation. Any good vendor as MagMike suggests can provide the curves.

Mike

isogen (Mechanical) · Answer 3 · 2009-03-17 09:52:36

That is helpful information. I have attached the two files I have gotten requesting this information. I tried putting in the information from the graphs, but Maxwell 3d v11.1 said that the curve can't be less than that of empty air, so it wouldn't accept the information I acquired by counting individual pixels. That is why I'm looking for a data listing.

http://files.engineering.com/getfile.aspx?folder=3c02eac2-993c-4034-b735-d0

MagMike (Materials) · Answer 4 · 2009-03-17 10:03:30

I do not use Maxwell.

What temperature(s) are you working with? For room temperature (20degC), N42 is a straight line according to the chart you posted.

What exactly do you have to input into Maxwell? Is it actual data points or is it Remanence (or Coercivity) and Recoil permeability.

isogen (Mechanical) · Answer 5 · 2009-03-17 11:37:16

I looked at the information they have input for N35s, and it appears that I was looking at the wrong curves. The up-and-right curve labeled 20C, which is the shape I'm used to seeing for that quadrant of the hysteresis graph, is what I was trying to input. Thanks for the heads-up, I'll go have some coffee.

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magnetic standards