Study on the Coercivity Mechanism of Nd-Fe-B Melt-spun Nanocrystalline Magnets

　　Study on the Coercivity Mechanism of Nd-Fe-B Melt-spun Nanocrystalline Magnets
　　The reversed magnetization process and the coercivity mechanisms for NdFeB nanocrystalline Rare-Earth permanent magnets are discussed and investigated by comparing the experimental results with calculated ones.Take a isotropic permanent magnet with single axis magnetocrystalline anisotropy for a sphere. Being satuated and removing the magnetizing field, Alnico Magnets all magnetization distribute equably on the upper hemisphere and the magnetization directions are normal to its surface. Divide such a hemisphere into 36 petals alone X axis. Angle this magnet withershins to an angle that is the multiple of 5°, then measure its magnetizing remanent magnetization curves along H direction. A series of magnetizing remanent magnetization curves is obtained.Such measurements is simulated in computer by dividing very petalinto a series of cell with different angles θ to http://www.999magnet.com/products/108-alnico-magnets H and calculating the H(θ)using pinning or nucleation model. It is found that the remanent magnetization curves calculated using pinning model resemble the experimental ones mostly, which confirm the reverse of magnetization is control by pinning.