Sintered neodymium iron boron magnet

Abstract

The invention relates to the technical field of rare earth permanent magnets, in particular to a sintered neodymium iron boron magnet and a preparation method thereof. The sintered neodymium iron boron magnet is characterized in that according to the mass percentage composition, the general formula of the sintered neodymium iron boron magnet is ReaDybFe100-a-b-c-dBcMd; Re is one or more of Pr, Nd,La, Ce, Gd and Ho; M is one or more of Co, Cu, Al, Nb, Ga, Zr, Ti and Cr; and a is larger than or equal to 27 and smaller than or equal to 33, b is larger than or equal to 1.0 and smaller than or equal to 2.0, c is larger than or equal to 0.9 and smaller than or equal to 1.1, and d is larger than or equal to 0 and smaller than or equal to 5. Through the optimized process, smelting, single hydrogen breaking and powder making are not needed, and the using amount of heavy rare earth can be reduced to 1.5wt% or even 1.2wt%, so that rare earth is more uniformly distributed in the grain boundary, and the effective utilization ratio of the rare earth is improved; and according to the sintered neodymium iron boron magnet prepared through the process, while cost is reduced, the excellent magneticproperties are achieved.

Description

technical field [0001] The invention relates to the technical field of rare earth permanent magnets, in particular to a sintered NdFeB magnet and a preparation method thereof. Background technique [0002] Since the sintered NdFeB permanent magnet material was invented in the 1980s, thanks to its high cost performance and the preparation process basis of sintered samarium cobalt magnets, it has rapidly realized industrialization. Sintered NdFeB permanent magnets are widely used in the computer industry, communication industry, audio products, medical and health industries, etc. With the continuous advancement of environmentally friendly industries such as hybrid vehicles and wind power generation, the market demand for sintered NdFeB magnets is also increasing. Sintered NdFeB magnets with high magnetic energy product can promote the development of products in the direction of lightness, thinness and miniaturization, and become an indispensable necessity in modern industry. ...

AI Technical Summary

Problems solved by technology

In addition, some double-high (high energy product, high coercivity) products can also be developed, such as 48UH, 52SH, etc., which can hardly be produced by conventional technology.

[0005] However, the heavy rare earth grain boundary infiltration and diffusion technology is still a relatively new technology at present, and there are still some problems in the specific production, such as unreasonable equipment design and manufacture, high waste and loss of heavy rare earth in the process, unstable product performance, poor consistency, and large product thickness limitations. many shortcomings

[0006] At present, in the actual large-scale production at home and abroad, the production is basically carried out by the double alloy process. The double alloy process is easy to obtain magnets with high coercivity, but as discussed above, due to the simple addition of heavy rare earth elements , while increasing the coercive force, the remanence of the magnet must be greatly reduced

[0007] Invention patent CN 103824668A adopts the method of mixing alloy powder and rare earth powder to obtain NdFeB magnets with low-weight rare earth and high coercive force. Invention patent CN 101266855A uses grain boundary material hydrogen breaking to make powder and then mixes it with alloy powder to reduce costs , but the separate milling of grain boundary substances is still cumbersome

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