Identifying Magnet Grade for FEMM Simulation: Neodymium Cylinder Magnets

[Papote]

TL;DR Summary

I need indetify a magnet grade from an academic paper but I only have the surface fields and the saturation magnetization.

Hello. I need to indetify a magnet grade from an academic paper, they dont mention what grade is . I am trying to simulate de contact force bewten two magnets on FEMM and to validate the results I am using one ecuation of that paper, but they dont specify what grade the Neodymium magnet is, only give the data that they got of a gaussmeter and the saturation magnetization the magnets are cylinders with D=3mm and H=1.5mm. The data of the gaussmeter is B= 1.07 T and the saturation magnetization M = (0.859) MA/m.

I tried to solve an equation that I found

and with Br I can search to what grade is, but when a solve the Br is higher even for N52 magnets.

Please Help me, I attach a part of the paper perhaps there is something that I can see.

Thank you

 

[marcusl]

I don’t know what “grade” is, but they list the dimensions, magnetic properties and the name of the manufacturer! Just look it up.

 

[berkeman]

I don’t know what “grade” is, but they list the dimensions, magnetic properties and the name of the manufacturer! Just look it up.

Yeah, I hadn't heard that term either, but from a web search it does seem to be something that the manufacturer would specify:

https://www.kjmagnetics.com/blog.asp?p=magnet-grade

 

[Haborix]

Need more information. The formula you gave doesn't help if we don't know how the coordinates used to derive it were setup. Could you identify the paper and where you got the equation?

 

[Papote]

Thank you for your answers. Like berkeman wrote, the grade is the classification of neodymium magnets for example N52 or N40. The paper is :
"Magnetostatic interactions and forces between cylindrical permanent magnets" by
David Vokoun, Marco Beleggia.

This paper used a permanent magnet, but they don’t explain what grade is, I need to know because depend on the grade are the properties for example the magnet strength. The paper only mention that they measured with a gaussmeter and got B= 1.07 T that I supposed is the magnetic field in the surface, so there is one equation in (https://www.supermagnete.de/eng/faq/How-do-you-calculate-the-magnetic-flux-density) to calculate the magnetic field on the surface I tried to use that equation to get the Br (residual magnetism) and with that I could found to what grade is. But it does not work. Because it gave me Br=2.41 T con z=0mm, and there aren´t materials with that Br.

 

[Papote]

Hi guys, finally I guess that I found the answer. The saturation magnetization is the higher part of the curve in a demagnetization curve :

image took from:
(https://mriquestions.com/magnetizing-metal.html)

So, with the saturation magnetization M = (0.859) MA/m I just search a magnet with the nearest value perhaps the NdFeB N30, it depends on the supplier.

For example, I found this supplier.
https://www.arnoldmagnetics.com/wp-content/uploads/2017/11/N30-151021.pdf
and the magnetic saturation is 11 kGauss comparing between M = (0.859) MA/m=10.7 KGauss I think its ok.

I hope this could help to someone.