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CN-120854101-B - High-performance lanthanum-cerium sintered neodymium-iron-boron magnet material and preparation method thereof

CN120854101BCN 120854101 BCN120854101 BCN 120854101BCN-120854101-B

Abstract

The invention discloses a high-performance lanthanum-cerium sintered neodymium-iron-boron magnet material and a preparation method thereof, wherein LaCe neodymium-iron-boron magnet alloy powder and a titanium carbide nano-sheet compound are used as raw materials to prepare the material, the titanium carbide nano-sheet compound is a nano-sheet compound containing any one or more of TiC and Ti 2 C、Ti 3 C 2 T, and T in Ti 3 C 2 T is an oxygen-containing functional group. The LaCe neodymium iron boron magnet alloy powder is modified by utilizing the titanium carbide nano-sheet compound, has rich chemical activity, can provide more heterogeneous nucleation sites in the magnet, and acts as a pinning point in the grain growth process to block movement of magnetic domain walls, so that the coercive force of the magnet is enhanced. The two-dimensional nano-sheet structure is distributed on the grain boundary in a layered manner, so that migration of the grain boundary and combination of grains can be prevented, and growth of the grains can be effectively inhibited. And the nano sheet structure forms a continuous magnetic domain wall pinning point to prevent nucleation and expansion of reverse magnetic domains.

Inventors

  • LI NA
  • LI SHENGYUAN
  • Feng Hanzhi
  • GAO CHU
  • LI SHUAI
  • HE PING
  • SUN NAN

Assignees

  • 绵阳巨星永磁材料有限公司

Dates

Publication Date
20260505
Application Date
20250805

Claims (10)

  1. 1. The high-performance lanthanum-cerium sintered neodymium-iron-boron magnet material is characterized in that the material is prepared from LaCe neodymium-iron-boron magnet alloy powder and a titanium carbide nano-sheet compound, wherein the titanium carbide nano-sheet compound is a nano-sheet compound containing any one or more of TiC and Ti 2 C、Ti 3 C 2 T, and T in Ti 3 C 2 T is an oxygen-containing functional group; The preparation process of the titanium carbide nano-sheet compound comprises the following steps: the titanium aluminum carbide powder is subjected to acid etching of an aluminum phase, centrifugation and ultrasonic stripping, and then dispersed in an organic solvent to obtain a titanium carbide nano-sheet compound; the acid is any one or more of hydrochloric acid, sulfuric acid and nitric acid, and the organic solvent is any one or mixture of petroleum ether and isopropanol.
  2. 2. The high performance lanthanum cerium sintered neodymium iron boron magnet material according to claim 1, wherein the oxygen-containing functional group is at least one of-OH, =o and-O; And/or, the titanium carbide nano-sheet compound also comprises TiO 2 .
  3. 3. The high-performance lanthanum cerium sintered neodymium-iron-boron magnet material according to claim 1, wherein the components of the LaCe neodymium-iron-boron magnet alloy powder are calculated according to mass fraction La 1.0-10.0 Ce 3.0-13.0 （Pr 0.25 Nd 0.75 ） 16.0 Fe 67.4 B 0.9 Co 0.1 Zr 0.1 Ti 0.1 Al 0.2 Cu 0.1 Ga 0.1 .
  4. 4. A method for preparing a high-performance lanthanum-cerium sintered neodymium-iron-boron magnet material according to any one of claims 1 to 3, comprising the following steps: preparing LaCe neodymium iron boron magnet alloy powder; preparing a titanium carbide nano-sheet compound; adding the titanium carbide nano-sheet compound into LaCe neodymium-iron-boron magnet alloy powder, mixing and stirring uniformly, and performing magnetic pressure forming and isostatic pressure maintaining to obtain a LaCe neodymium-iron-boron magnet compact; and sintering the LaCe neodymium iron boron magnet compact, and performing primary tempering and secondary tempering to obtain the high-performance lanthanum cerium sintered neodymium iron boron magnet material.
  5. 5. The method for preparing a high-performance lanthanum-cerium sintered neodymium-iron-boron magnet material according to claim 4, wherein the particle size range of the LaCe neodymium-iron-boron magnet alloy powder is 2.9 μm-4.5 μm.
  6. 6. The method for preparing the high-performance lanthanum-cerium sintered neodymium-iron-boron magnet material according to claim 4, wherein the preparation process of the LaCe neodymium-iron-boron magnet alloy powder is as follows: Weighing the alloy elements according to the proportion, mixing, smelting and casting to obtain a LaCe neodymium iron boron magnet alloy rapid hardening sheet, and carrying out hydrogen crushing and nitrogen protection air flow grinding on the LaCe neodymium iron boron magnet alloy rapid hardening sheet to obtain LaCe neodymium iron boron magnet alloy powder; and/or smelting at 1400 deg.c with vacuum degree of 0.05Pa and casting with thin belt casting process; And/or, hydrogen is absorbed at room temperature in the hydrogen crushing process, and dehydrogenation treatment is carried out at 590 ℃.
  7. 7. The method for preparing the high-performance lanthanum-cerium sintered neodymium-iron-boron magnet material according to claim 4, wherein the preparation process of the titanium carbide nano-sheet composite is as follows: And (3) carrying out acid etching on the aluminum phase, centrifuging and ultrasonic stripping on the titanium aluminum carbide powder, and dispersing the titanium aluminum carbide powder in an organic solvent to obtain the titanium carbide nano-sheet compound.
  8. 8. The preparation method of the high-performance lanthanum-cerium sintered neodymium-iron-boron magnet material according to claim 7, wherein the acid is any one or more of hydrochloric acid, sulfuric acid and nitric acid, and the organic solvent is any one or a mixture of petroleum ether and isopropanol; and/or the organic solvent is a mixed solution of petroleum ether and isopropanol, and the volume ratio is 1:1.
  9. 9. The preparation method of the high-performance lanthanum-cerium sintered neodymium-iron-boron magnet material according to claim 4, wherein the adding amount of the titanium carbide nano-sheet compound is 0.5-3.5wt% of the weight of the LaCe neodymium-iron-boron magnet alloy powder.
  10. 10. The method for preparing a high-performance lanthanum-cerium sintered neodymium-iron-boron magnet material according to claim 4, wherein the sintering temperature of the LaCe neodymium-iron-boron magnet compact is 1070 ℃, the sintering time is 6h, the primary tempering temperature is 700 ℃, and the secondary tempering temperature is 400 ℃.

Description

High-performance lanthanum-cerium sintered neodymium-iron-boron magnet material and preparation method thereof Technical Field The invention relates to the technical field of rare earth permanent magnet materials, in particular to a high-performance lanthanum-cerium sintered neodymium-iron-boron magnet material and a preparation method thereof. Background In the field of rare earth permanent magnet materials, the preparation of sintered NdFeB magnets by using high-abundance rare earth elements lanthanum (La) and cerium (Ce) to replace rare resources has become a core strategy for balancing resource structures, reducing cost and improving efficiency. However, the intrinsic magnetic defect of La/Ce, namely the main phase saturation magnetization (Ms) and magnetocrystalline anisotropy field (HA) attenuation caused by low atomic magnetic moment, magnetic isolation failure and reverse magnetization domain nucleation caused by grain boundary weak magnetic hetero phase, severely restrict the improvement of magnet coercivity (Hcj) and remanence (Br), and limit the application of the La/Ce. In the prior art, the performance of the lanthanum-cerium-containing magnet is optimized by a double-alloy method, grain boundary diffusion, adding auxiliary elements such as dysprosium (Dy), gadolinium (Gd), holmium (Ho) and the like, so as to realize the cooperative breakthrough of cost and performance. In the patent document with the publication number of CN113782330A, alloy powder without lanthanum and cerium is added as auxiliary alloy to weaken the magnetic property deterioration caused by lanthanum and cerium addition, but the method needs to independently prepare two groups of alloys, so that the process difficulty is improved, the defect of performance dispersion caused by uneven main and auxiliary phase components is easily caused, the penetration amount of the LaCe by grain boundary diffusion is limited, and the La and Ce on the diffusion surface are easily oxidized to generate nonmagnetic hetero phases, so that the coercivity cliff of the magnet is reduced. Therefore, when La and Ce are used for the neodymium-iron-boron magnet, the technical problems of magnet coercivity cliff type drop, process complexity, high manufacturing cost, easy growth of crystal grains, heavy rare earth dependence and the like are still faced when lanthanum and cerium are added. In order to further solve the existing problems, nano additive powder such as carbide, oxide and the like is added into a magnet, and acts on a local area to play a role of grain boundary pinning, so that magnetic performance is regulated. However, the additive particles are difficult to uniformly disperse in the magnet due to agglomeration and segregation of additive powder generated by density and particle size difference, and heterogeneous doping of aggregated granular powder agglomerates in the grain boundaries of the magnet may damage the microstructure continuity of the grain boundaries, so that not only the grain boundary phase cannot be effectively optimized, but also stress concentration or impurity defects may be caused, and further the magnetic performance is deteriorated. In addition, the nano particles can only provide isolated pinning points, the pinning effect is limited, and the coercivity improving capability is limited. In view of this, the present patent application is presented. Disclosure of Invention In order to solve the technical problems of decreased coercivity, complex process, easy growth of crystal grains, degradation of magnetic performance caused by heterogeneous doping and the like faced by using La and Ce in the neodymium-iron-boron magnet, the invention provides a high-performance lanthanum-cerium sintered neodymium-iron-boron magnet material and a preparation method thereof, and realizes optimization and adjustment of the magnetic performance of the neodymium-iron-boron magnet sintered by La, so as to meet the development requirements of the neodymium-iron-boron sintered by La, break through the bottleneck of cost control and performance guarantee and widen the application possibility of high-abundance rare earth in the neodymium-iron-boron magnet. The invention adopts the following technical scheme: the first aim of the invention is to provide a high-performance lanthanum-cerium sintered neodymium-iron-boron magnet material, which is prepared by taking LaCe neodymium-iron-boron magnet alloy powder and a titanium carbide nano-sheet compound as raw materials, wherein the titanium carbide nano-sheet compound is a nano-sheet compound containing one or more of TiC and Ti 2C、Ti3C2 T, and T in Ti 3C2 T is an oxygen-containing functional group. According to the invention, the LaCe neodymium iron boron magnet alloy powder is modified by utilizing the titanium carbide nano-sheet compound, nano-sheets show different compound valence states such as TiC, ti 2C、Ti3C2 T and the like, and TiC and Ti 2C、Ti3C2 T in different valence states exist in th