Magnetising a hard magnetic material

AI Thread Summary
Magnetizing hard magnetic materials like steel using an AC source is not feasible due to the oscillating magnetic field produced, which averages to zero. This means that magnetization cannot exceed the material's remanence. The frequency of the AC current can further reduce effective magnetization, as ferromagnetic materials require time to respond to changes in magnetic fields. The process of magnetization is non-equilibrium and can take seconds to stabilize, making it impractical for AC applications. Overall, attempting this method could pose safety risks.
Kenny Low
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Is it possible to magnetize steel (hard magnetic material) with an ac source?
 
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I'm quite certain it can not. An AC current makes an oscillating B-field. The time-averaged value of the B-field is therefore, zero. Hence, no magnetization greater than the remanence can be achieved, and depending on the frequency (keep in mind that the magnetization of a ferromagnet is a highly non-equilibrium process and time constants for changes in magnetization can be of the order of seconds, even at normal temperatures) it could be significantly smaller.
 
This sounds like a very dangerous home-made experiment waiting to happen :biggrin:
 
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