Magnetic properties of high coercivity melt-spun didymium-Fe-Co-Nb-V-Tb-B system ribbons and their bounded magnets

The effects of Tb substitution for Fe in melt-spun ribbons of didymium-Fe-Co-Nb-V-Tb-B system alloys on the magnetic properties and the temperature dependence of the ribbons and their bonded magnets are investigated. The compression molding isotropic bonded magnets are made by using melt-spun didymium-Fe-Co-Nb-V-Tb-B powder crushed under 150 μm. After 4.8 MA/m pulsed magnetization, the magnetic properties of the ribbons, Curie temperature and temperature coefficient of H_cJ and J_r for ribbons are measured by a vibrating sample magnetometer. The structural properties of the ribbons are examined using X-ray diffraction and transmission electron microscopy. The results show high quality magnetic properties in the melt-spun ribbons with high coercivity. The demagnetization curves and temperature dependence of the bonded magnets are also shown.