Search

CN-122025325-A - Thermal deformation permanent magnet material and preparation method thereof

CN122025325ACN 122025325 ACN122025325 ACN 122025325ACN-122025325-A

Abstract

The invention discloses a thermal deformation permanent magnet material and a preparation method thereof, wherein the thermal deformation permanent magnet material is prepared by hot-pressing densification and thermal deformation of composite magnetic powder, the composite magnetic powder comprises, by weight, 55-82 parts of first quick quenching magnetic powder and 18-45 parts of second quick quenching magnetic powder, wherein the first quick quenching magnetic powder is R1-Fe-B series magnetic powder, R1 is at least one of Nd and Pr, the total atomic percentage of rare earth elements in the first quick quenching magnetic powder is 12.5-15.5at%, the second quick quenching magnetic powder is R2-Fe-B series magnetic powder, R2 comprises Nd and at least one of La and Y, the sum of the atomic percentages of La and Y in the second quick quenching magnetic powder is 1.2-10.0at%, the first quick quenching magnetic powder and the second quick quenching magnetic powder are filled in a partition mode in a blank body along the pressing direction before hot pressing, and the area where the first quick quenching magnetic powder and the second quick quenching magnetic powder are located are distributed along the pressing direction in sequence. The invention can improve the structural uniformity and the performance consistency of the thermal deformation permanent magnet material.

Inventors

  • ZHENG YAN
  • ZHANG KAIFEI

Assignees

  • 广东南磁科技有限公司

Dates

Publication Date
20260512
Application Date
20260407

Claims (9)

  1. 1. A thermal deformation permanent magnetic material is prepared from composite magnetic powder through hot pressing densification and thermal deformation, the composite magnetic powder comprises, by weight, 55-82 parts of first quick quenching magnetic powder and 18-45 parts of second quick quenching magnetic powder, wherein the first quick quenching magnetic powder is R1-Fe-B series magnetic powder, R1 is at least one of Nd and Pr, the total atomic percentage of rare earth elements in the first quick quenching magnetic powder is 12.5-15.5at%, the second quick quenching magnetic powder is R2-Fe-B series magnetic powder, R2 comprises Nd and at least one of La and Y, the sum of atomic percentages of La and Y in the second quick quenching magnetic powder is 1.2-10.0at%, the first quick quenching magnetic powder and the second quick quenching magnetic powder are filled in a partition mode in a blank body along a pressing direction before hot pressing, and the areas where the first quick quenching magnetic powder and the second quick quenching magnetic powder are located are distributed in sequence along the pressing direction.
  2. 2. A thermally deformable permanent magnet material as claimed in claim 1, wherein said composite magnetic powder comprises, in parts by weight, 60-75 parts of said first rapidly quenched magnetic powder and 20-35 parts of said second rapidly quenched magnetic powder.
  3. 3. The heat deformable permanent magnet material of claim 1, wherein the alloy composition of the first rapidly quenched magnetic powder comprises, in atomic percent, nd 11.5-14.0 at%, pr 0-2.5 at%, B5.5-6.5 at%, cu 0.05-1.2 at%, ga 0.05-0.8 at%, and at least one additive element selected from Co, al, nb, zr in atomic percent together 0-3.0 at%, with the balance being Fe.
  4. 4. The heat deformable permanent magnet material of claim 1, wherein the alloy composition of the second rapidly quenched magnetic powder comprises, in atomic percent, nd 6.0-12.0 at%, la 1.0-6.0 at%, Y0.2-4.0 at%, pr 0-2.0 at%, B5.5-6.5 at%, cu 0-1.0 at%, ga 0-0.8 at%, and at least one additive element selected from Co, al, nb, zr in atomic percent together 0-2.5 at%, with the balance being Fe.
  5. 5. The heat deformable permanent magnet material of claim 1, wherein the composite magnetic powder further comprises a transition magnetic powder, the transition magnetic powder is located between the region where the first rapid quenching magnetic powder is located and the region where the second rapid quenching magnetic powder is located, based on 100 parts by weight of the total amount of the composite magnetic powder, the transition magnetic powder is R3-Fe-B rapid quenching magnetic powder, wherein R3 comprises at least one of Nd and La and Y, the total atomic percentage of rare earth elements in the transition magnetic powder is 11.0-14.5 at%, and the sum of atomic percentages of La and Y is 0.5-5.0 at%.
  6. 6. A preparation method of a thermal deformation permanent magnet material is characterized in that the composite magnetic powder of claim 1 is adopted, the first quick quenching magnetic powder and the second quick quenching magnetic powder are partition-filled in a pressing direction before hot pressing to form a composite green body, the composite green body is subjected to hot pressing densification, and then the green body after hot pressing is subjected to thermal deformation to obtain the thermal deformation permanent magnet material.
  7. 7. The method of producing a thermally deformable permanent magnet material of claim 6, wherein the division filling is sequentially performed in layers in the pressing direction in the order of the first rapidly quenched magnetic powder, the second rapidly quenched magnetic powder, and the first rapidly quenched magnetic powder.
  8. 8. The method for preparing a thermally deformable permanent magnet material as claimed in claim 6, wherein the hot-press densification is performed under vacuum or inert atmosphere, the hot-press temperature is 620-760 ℃, the hot-press pressure is 80-220 MPa, and the dwell time is 1-20 min.
  9. 9. The method for preparing a thermally deformable permanent magnet material as claimed in claim 6, wherein the thermal deformation is performed under vacuum or inert atmosphere, the thermal deformation temperature is 720-860 ℃ and the strain rate is the preparation method, and the method further comprises an annealing treatment step after the thermal deformation is completed, wherein the annealing treatment is performed under vacuum or inert atmosphere, the annealing temperature is 450-650 ℃ and the annealing time is 0.5-8 h.

Description

Thermal deformation permanent 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 thermal deformation permanent magnet material and a preparation method thereof. Background The thermal deformation rare earth permanent magnetic material is generally represented by Nd-Fe-B system, and is formed by carrying out hot pressing densification and further thermal deformation treatment on the quick quenching magnetic powder, so that orientation rearrangement of original nanocrystalline equiaxed grains occurs under the action of external pressure and temperature, and a magnet with a flaky crystal structure and anisotropy is formed. The material has high magnetic energy product and good processing performance, and can be widely applied to the fields of new energy automobiles, motors, electronic devices and the like. In recent years, in order to reduce the use cost of high-abundance rare earth elements Nd and Pr, low-cost rare earth elements such as La, ce, Y and the like are gradually introduced in researches to partially replace a main phase, but the introduction of the elements can influence the magnetic performance of the main phase and the structure of a grain boundary phase, so that the tissue evolution behavior of the material in the thermal deformation process is more complex. In the prior art, two types of technical paths are generally adopted to solve the problems, namely, one type is to prepare quick quenching magnetic powder by directly doping low-cost rare earth elements in a main phase or adopting mixed rare earth raw materials, and then obtain a magnet through hot pressing and thermal deformation, and the other type is to introduce low-melting-point rare earth alloy or rare earth-rich phase through mixing or subsequent diffusion treatment of bi-component magnetic powder so as to improve grain boundary structure and magnetic performance. However, most of the methods focus on component regulation or overall uniform mixing treatment, and under the influence of uneven stress conditions in different areas and deformation behavior differences of all components in the thermal deformation process, the phenomenon of uneven structure inside the material is still easy to form. Further analysis shows that after the low-cost rare earth elements participate, the continuity and stability of the grain boundary phase of a part of areas are poor, so that the orientation rearrangement of crystal grains in the thermal deformation process is limited, and the consistency of the overall performance of the magnet is further affected. Therefore, the prior art is difficult to effectively solve the problems of structural uniformity and performance coordination of the material in the thermal deformation process while considering the cost and the performance. Disclosure of Invention The invention mainly aims to provide a thermal deformation permanent magnet material, and aims to solve the technical problems of poor structure uniformity, limited grain orientation rearrangement and insufficient performance coordination in the thermal deformation process of the existing thermal deformation rare earth permanent magnet material containing low-cost rare earth elements. The thermal deformation permanent magnet material is prepared from 55-82 parts by weight of first quick quenching magnetic powder and 18-45 parts by weight of second quick quenching magnetic powder through hot pressing densification and hot deformation, wherein the first quick quenching magnetic powder is R1-Fe-B magnetic powder, R1 is at least one of Nd and Pr, the total atomic percentage of rare earth elements in the first quick quenching magnetic powder is 12.5-15.5at%, the second quick quenching magnetic powder is R2-Fe-B magnetic powder, R2 comprises at least one of Nd and La and Y, the sum of atomic percentages of La and Y in the second quick quenching magnetic powder is 1.2-10.0at%, the first quick quenching magnetic powder and the second quick quenching magnetic powder are filled in a blank in a partition mode along the pressing direction before hot pressing, and the areas where the first quick quenching magnetic powder and the second quick quenching magnetic powder are located are distributed in sequence along the pressing direction. Optionally, the composite magnetic powder comprises, by weight, 60-75 parts of the first quick-quenching magnetic powder and 20-35 parts of the second quick-quenching magnetic powder. Optionally, the alloy composition of the first quick quenching magnetic powder comprises, by atomic percentage, 11.5-14.0 at% of Nd, 0-2.5 at% of Pr, 5.5-6.5 at% of B, 0.05-1.2 at% of Cu, 0.05-0.8 at% of Ga, 0-3.0 at% of the sum of atomic percentages of at least one additive element selected from Co, al, nb, zr, and the balance of Fe. Optionally, the alloy composition of the second rapid quenching magnetic powder comprises, by atomic percent