Does Every Iron Core Have the Same Relative Permeability?

[Dash-IQ]

B = μ₀nI
Usually, the value of B is quite small...
I'd like to boost the magnetic field B to a much larger and stronger field, and the most efficient way I find to do that is using a high permeability core B = ku₀nI.
What is the average μ_r of an iron core? They range from what value?
Do all iron have the same relative permeability?

 

[Dash-IQ]

+ With the use of a high permeability ferromagnetic cores, it makes it more practical for electromagnets to have a magnetic field a Tesla and possibly higher?

 

[Meir Achuz]

For most iron, mu changes drastically with I.
It also depends on what you want the core to do. For an electromagnet or transformer you want B to go back to zero elastically when I goes to zero. For more permanent magnetism, you want a fat hysteresis loop.

 

[Dash-IQ]

For most iron, mu changes drastically with I.

Can you elaborate please on that(i.e example with values)?
Are u_r of ferromagnets based on I? or are they a constant value when I = 0 or I = x Amps?
Is it true that their u_r are over a 1000?

The rest I'm quite familiar with, as you are describing soft core(e.g iron low coercivity), and hard core's that are best when creating permanent magnets with(e.g neodymium low coercivity wider hysteresis area).

 

[PJC01]

I would like to clarify that not all iron is a good core. The effectiveness of an iron core depends on its relative permeability (μr) which is a measure of how easily a material can be magnetized. The higher the μr, the better the material is at amplifying the magnetic field.

In the equation B = μ0nI, μ0 is the permeability of free space and nI is the number of turns of wire and the current flowing through them. This equation is used to calculate the magnetic field strength (B) in a solenoid. However, the value of B is usually quite small and may not be sufficient for certain applications.

To boost the magnetic field strength, using a high permeability core, as described in the equation B = μ0knI, is a good approach. The constant k represents the relative permeability of the core material and can greatly enhance the magnetic field strength.

The average μr of an iron core can vary depending on the type of iron used. Generally, the range of μr for iron cores is between 200-5000. This is much higher than the μr of free space which is 1.

It is important to note that not all iron has the same relative permeability. The μr of iron can vary depending on its composition, purity, and processing methods. Therefore, it is crucial to carefully select the type of iron core for a specific application based on its relative permeability.