A preparation method for enhancing the coercive force of sintered NdFeB by organic heavy rare earth complexes

Abstract

The invention discloses a preparation method for enhancing the coercive force of sintered NdFeB by organic heavy rare earth complexes. The mixed liquid of organic heavy rare earth complex and ether is injected into the NdFeB alloy powder; the mixed material is magnetically oriented, pressed into a rough magnet, and sintered. The invention adds the mixture of rare earth complexes and ether in a spraying manner, which can effectively prevent particles from contacting with oxygen, reduce the oxygen content of magnetic particles, and improve the distribution uniformity of organic heavy rare earth complexes between grain boundaries of sintered magnets. The addition of organic heavy rare earth complexes decomposes with the increase of sintering temperature, and the residual heavy rare earth ions will be evenly distributed on the surface of NdFeB magnetic particles, and penetrate into the interior of NdFeB particles under the action of high temperature, thereby improving the magnetic crystal of the main magnetic phase. Anisotropy and coercivity. The process is simple and easy to operate, and is suitable for mass production.

Description

technical field [0001] The invention belongs to the technical field of rare earth permanent magnet materials, and in particular relates to a preparation method for enhancing the coercive force of sintered NdFeB by an organic heavy rare earth complex. Background technique [0002] Metal-based rare earth permanent magnet materials have been a very eye-catching research and development hotspot in the field of magnetism and magnetic material industry for forty years. The main types are neodymium iron boron, samarium cobalt and alnico and so on. At present, the most widely used metal-based rare earth permanent magnet material in the world is mainly NdFeB, which is widely used in high-tech fields such as voice coil motor VCM of computer drives, new motors, and nuclear magnetic resonance imaging MRL. With the rapid development of science and technology, in order to meet the needs of miniaturization, light weight, high performance and high reliability of components and equipment, th...

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Problems solved by technology

China's magnetic material manufacturers are also constantly developing heavy rare earth doping technology. Although the coercive force and service temperature of the products prepared by the existing process have been improved, the preparation process design is mainly in the alloy formula. Directly adding heavy rare earth alloys and single-element heavy rare earth nanoparticles, etc., or infiltrating terbium or dysprosium heavy rare earth oxides on the surface, etc., will cause the sintering temperature and tempering temperature to be too high, and the abnormal growth of grains cannot be effectively controlled; in addition, Doped heavy rare earths are mainly distributed in the main phase Nd 2 Fe 14 B inside and outside the grain, leading to excessive doping of heavy rare earths, thereby increasing costs and wasting heavy rare earth resources

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