注射成型粘结稀土永磁体的研制

　　注射成型粘结稀土永磁体的研制
　　This article discusses in the foundation of the injection rare earth permanentmagnet compounded lnaterials, and pointing out main problems which exists in thedevelopment and the production areas. The rare earth magnetic powder’s surface,composition for rare earth bond magnet, and property of the injection rare earth permanentmagnet compounded materials were studied. Furthermore, the relationship between theflow of the injection and the property of the materials was discussed.The surface properties of rare earth magnetic powder and polymer resin areentirely different, so their compatibility is very bad. In order to get two unions togetherwell, their compatibility must be changed firstly. The surface impact between the rareearth magnetic powders and the polymer resin was weak, and the dispersity of themagnetic powders in resin was bad when the content of the Block neodymium magnet rare earth magnetic powderswere in high fills. How to improve the rare earth magnetic powder’s dispersivity inpolymer, and how to enhance the surface contact, were studied in the paper. The use ofdifferent types of the coupling could improve the rare earth magnetic powder’s surface,and enhance the compatibility between the magnetic powder and the polymer. Theresults of experiment indicated that under the suitable dosage and the flow condition,use of the KH-550 coupling could modify the magnetic powder’s surface, enhancecompatibility between the rare earth magnetic powder and the polymer substrate, andimprove the dispersity of magnetic powder in polymer, so the compound materialdisplayed high longitudinal strength and high elongation ratio. Simultaneously, theresults of experiment showed that the KH-550 coupling could also improve the anti-oxidized ability of the magnetic powder under high temperature.In order to obtain high magnetism performance product, the content of magneticpowder in compound materials was very high; meanwhile, the mixture of grains waschanged to be difficult, and the dispersity of the magnetic powder was changed to bebad. If the fluidity of the injection was bad, the appearance of the product would berough, brittle, and very difficult to satisfy the actual application.
　　In order to improve thefluidity of the melting-body in full filling condition, different types of lubricant function were used in the paper. Though the metallic soap might enhance the fluidity of themelting-body, the dosage was huge, which might cause drops on the mechanics intensityof the product, and cause magnet to be crisp and easy to crack. EBS might enhance http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php thefluidity on melting-body and keep mechanic intensity of the compound materials to behigh. EBO could not only enhance the fluidity of melting-body, but also enhance themechanic intensity of the compound materials。In order to acquire different properties of the rare earth magnet, the relationshipbetween the content of magnetic powders and properties of the compound materials wasstudied. The magnetic property of the compound materials would be high if thecontent of the powders is high. While, high content of the magnet powders may causethe fluidity to become bad and hard to forming and process, and the mechanic intensityto drop sharply. When the neodymium iron boron (NdFeB) magnetic powder content is94 wt %, or the samarium cobalt (SmCo) magnetic powder content is 95 wt %, idealinjection bond magnets might be obtained.In conclusion, the influence of the flow condition to the magnetism performance,and emphases of the injection flow condition to the aeolotropism samarium cobaltmagnet were studied in the paper. In order to obtain the injection samarium cobaltmagnets with high performance, high injection temperature, mould temperate andquickly injection speed must be needed.