Preparation Method Of Samarium Cobalt Magnet

Samarium cobalt magnets refer to permanent magnet materials made of rare earth metals and transition metal alloys through a certain process. Because of their high magnetic energy product, stable magnetic properties, and good mechanical properties, they are widely used in machinery, electronics, instruments, medical and other fields. Coercive force (He ) is one of the important technical indicators of samarium cobalt magnet materials, representing the ability of magnetism to retain magnetic properties. However, the samarium cobalt magnet material in the prior art, such as the 2:17 type samarium cobalt magnet material, has an inherent coercivity of 20K0e at room temperature, and the resistance to external inverse magnetic fields and other demagnetization effects needs to be further improved. How to make cobalt magnets!

The technical problem to be solved by the present invention is to overcome the above shortcomings of the prior art and provide a samarium cobalt permanent magnet material with high coercivity. The technical scheme adopted in the present invention aims to provide a samarium cobalt magnet permanent magnet material, which is composed of samarium, cobalt, iron, copper, zirconium and heavy rare earth elements, and in terms of mass percentage, is samarium 23 25.5%, cobalt 44 50% %, Fe 14 20%, Copper Preferably, one of the above heavy rare earth elements is erbium. Another technical problem to be solved by the present invention is to provide a method for producing the samarium cobalt permanent magnet material of the present invention, and the samarium cobalt permanent magnet material produced by the method has high coercivity. The manufacturing method of samarium cobalt permanent magnet material includes the following steps:

1) Raw materials: Samarium, cobalt, iron, copper, zirconium and a heavy rare earth element are distributed as raw materials by mass percentage. Samarium 23 25.5%, cobalt 44 50%, iron 14 20%, copper 3 8%, zirconium 2 4%, heavy rare earth elements 0.5%.

2) Put the raw material prepared by dissolving the alloy into a vacuum intermediate frequency induction furnace to dissolve, and after the dissolution is completed, continue to heat and refine for 5 minutes at a temperature of 1430 ~ 1450 c, and inject it into the mold to obtain a samarium cobalt alloy. The mold is generally preferably a water-cooled copper type.

3) Magnetic powder manufacturing The samarium cobalt alloy is subjected to hydrogen crushing and ball milling to obtain magnetic powder with a particle size of 3.0 5.0 m. Hydrogen fragmentation refers to passing hydrogen in a reaction vessel equipped with samarium cobalt alloy, so that the hydrogen pressure reaches 1MPa, the temperature rises to 150°C, and the temperature is maintained for 20h, so that the samarium cobalt alloy and hydrogen undergo a hydrogen storage reaction and become saturated; after the reaction, the Raise the temperature to 300~400°C. Insulate the swimming pool to completely dehydrogenate the reaction product. In this process, the samarium cobalt alloy is broken along the grain boundary, and the magnet achieves the purpose of powdering under the condition of ensuring the integrity of the crystal.

4) The orientation and shaping magnetic powder is oriented under the magnetic field of 1.8 ) 2.ot, and after pressing and forming, cold isopressing is carried out under the pressure of 200 (300 mi ) to obtain the first samarium cobalt blank.

5) Sintering solid solution in the sintering furnace, unbalanced sintering the first samarium cobalt temporary sintered body under the protection of inert gas argon, temporarily sintering the whole sintered body at 10501180 for 2030Min, and sintering at 12001210 for 90100Min in the second time period , The unbalanced sintering method of solid solution 90100Min at 11681190 in the third time period refers to monitoring the electrothermal pairs of multiple blocks in the sintering furnace in real time, and adjusting the heating power in real time according to the temperature of the electrothermal pairs, so that the multiple zones The temperature of the blocks is the same.

6) the aging treatment is to heat the second samarium cobalt blank for 835 (7) h at 845c, then cool down to 400C at a speed of 0.5) 0.6/min, keep 3 plutonium, and air-cool to room temperature after the insulation to obtain the samarium cobalt magnet and the previous formula. In contrast, the present invention is formulated with erbium element, the microstructure of the samarium cobalt alloy is a cellular structure, the coercive force of the alloy comes from the pinning of the cellular structure to the domain wall, and the grain boundary precipitates also have nails in the domain wall. The zirconium content in the present invention is 2.4%, which is higher than that of the usual formulation The content of 13%, zirconium promotes the formation of flaky 2:17 phase, and the increase of flaky phase is beneficial to the improvement of coercivity.

Through the addition of erbium and the reasonable ratio of the formula, the inherent coercive force Hcj of the prepared samarium cobalt magnet material reaches 27￣koe, which is much higher than the coercive force of about 20K0e of the existing formula, which effectively meets the requirements of the high-tech field. Requirements for high coercivity of samarium cobalt magnet materials. In the manufacturing method of the samarium cobalt permanent magnet material of the present invention, the samarium cobalt alloy ingot is pulverized by the hydrogen crushing process, and the unbalanced sintering method is used to make the sintering temperature of each temperature zone in the sintering furnace the same to form a more uniform microstructure, This also improves the coercivity to a certain extent; the present invention performs aging treatment on the samarium cobalt billet at a cooling speed lower than that of the prior art, and by slowing down the cooling speed, the samarium cobalt alloy is fully dissolved in each other, and the microstructure is better. For the purpose of uniformity and size reduction, the coercive force is improved, and the reverse magnetic field and other demagnetization from the outside are prevented.

The above is the preparation method of samarium cobalt magnet. If you want to know more, please feel free to contact us!