The Study On The Magnetic Properties Of(Fe,Co)-RE-B-M(M=Cu,Nb) Permanent Magnetic Materials Alloy

(Fe,Co)-RE-B-M-based (M=Cu,Nb) nanocrystalline perment magnetic material is a new magnetic materials which has very excellent comprehensive performance.This material use soft magnetic phase of high strength and hard magnetic saturation magnetization of the characteristics of the high coercive force phase, In nano size range,through the exchange coupling between the the soft and hard phases the materials can be obtained very good hard magnetic properties.According to the theory of magnetism,the maximum energy product (BH)max can reach1MJ/m3,which is higher than all previous single-phase permanent magnetic material energy of the product. Such materials has a broad market prospect because of the lower production cost,and the superior performance.But now the magnetic properties of the Fe-Nd-B-based nanocrystalline permanent magnetic are far less than theoretical values. When was mainly due to the crystallization of amorphous alloys, soft magnetic phase precipitation temperature is lower than the precipitation temperature of the hard magnetic phase, when the hard magnetic phase begins to precipitate, the soft magnetic phase had grown up to reach the exchange coupling effect. So how to get nice and uniform nanocrystalline grain become the focus of the study of nanocrystalline (Fe,Co)-RE-B-M permanent magnet materials.This paper studied the effect of different crystallization time and addtion Cu and Nb on the magnetic performance of the B-rich Nd-Fe-B-based nanocrystalline permanent magnetic material,and the effect of addtion Cu on magnetic performance of the Fe-rich Nd-Fe-B-based nanocrystalline permanent magnetic material.The master alloy ingots were prepared by vacuum arc melting furnace, the designed alloy was prepared to amorphous ribbons by a melt-spinning technique, and the ribbons were respectively examined by XRD and DSC,The results show that:The ribbons were amorphous alloy,according to the results of DSC we confirmed the heat treatment process. The structure of the annealed alloys ribbons was examined by x-ray diffraction.The magnetic performance of the annealed alloys powder was examined by VSM,and some powder was used to prepare bonded magnets.We discuss the influence on the structure of permanent magnet materials by different crystallization time, and then discuss the impact of its magnetic properties. The results showed that:With the extension of the crystallization time,the magnetic properties of the permanent magnetic material increased at frist and then decreased, which is due to the grain growth.The influences of the partial substitution of Cu or Nb for Co on the magnetic properties of the nanocrystalline Fe67C09.5Nd3Dy0.5B20alloy are investigated. With the increasing of Cu, the magnetic properties of Fe-Co-Nd-Dy-B-Cu-Nb alloy increase gradually,when the content of Cu is0.5at%,the maximum energy product (BH)m is46.416kJ/m3,this is because the Cu addition is belived to reduce the grain size of nanocrystalline phases,which enhance the exchange coupling interaction. Combined addition of Cu and Nb into Fe-Co-Nd-Dy-B-Cu-Nb alloy reduces the magnetic properties. This is due to introduction of too much the non-magnetic element,however,addition of Nb can improves the GFA of the alloy.Adding a small amount of Cu improves the magnetic properties of (Nd,Pr)8.5Fe84.5Nb0.5Zr0.5B6alloy, this is because the Cu addition is belived to reduce the grain size of nanocrystalline phases too,and improve the magnetic properties of permanent magnet materials. At the same time, the partial substitution of Pr for Co can increase the coercive force of the magnets, the maximum energy product (BH)m of (Nd0.8Pr0.2)8.5Fe84Nb0.5Zr0.5Cu0.5B6alloy is64.8kJ/m3.The properties of bonded magnets depends on the properties of the magnetic powder, At the same time,which have to do with forming density factors.The properties of bonded magnets are generally lower than The properties of magnetic powder.