MAGNETIC PROPERTIES OF AND-FE-B BONDED MAGNET USINGA

Permanent magnets have been widely used in various applications for many decades to convert electrical energy into mechanical energy or vice versa. Hard magnetic nanocrystalline materials such as Nd-Fe-B alloys are a new family of magnets which show unexpected properties such as a high energy density even in an isotropic state. Principal synthesis methods of these materials include high energy ball milling, melt spinning and hydrogen assisted methods such as reactive milling and hydrogenation-disproportionation-desorption-recombination (HDDR) process. Powders prepared by melt spinning with Nd2Fe14B as the hard magnetic phase have an average grain size of 30-50 nm. This leads to development of isotropic magnetic properties. In this work, bonded magnets were produced by using a nanocrystallineNd-Fe-B powder made from a melt spinning technique. The samples were produced from a mixture of isotropic powder and an epoxy resin as binder using a compression-molding technique. The morphology and average particle size of the powders were investigated by an SEM, the average grain size of the Nd2Fe14B type phase was identified using a TEM, and the magnetic properties of the bonded magnets were measured by using a hysteresis loop tTacer.

Keywords:

Permanent magnets , nanocrystalline materials , Nd-Fe-B , epoxy resin , magnetic properties