Effect of magnetic powder content on circumferential anisotropy of centrifugally cast bonded magnets

摘要

The current paper focuses on determining the degree of powder orientation in a magnet centrifugally cast in a magnetic field and on determining the influence that the amount of ferromagnetic powder has on this parameter. Strontium ferrite powder and epoxy resin were used as starting materials. The manufactured magnets were cylindrically shaped and had a circumferential orientation. It was shown that the magnetic powder particles were oriented along the easy axis of magnetization in the direction tangential to the cylinder's surface. On the basis of magnetic measurements, it was found that the powder particles' degree of orientation decreases with increasing powder content in the magnet. For small contents of up to 20 vol% magnetic powder, a significant degree of orientation of the powder particles was observed. It was found that at 60 vol% magnetic powder content, the obtained magnets are isotropic. It was observed that at higher powder content, particle chains aligned with the magnetic field lines begin to interact with each other, which as a consequence causes the deterioration of particle orientation.