R-T-B-BASED PERMANENT MAGNET MATERIAL, PREPARATION METHOD THEREFOR AND USE THEREOF

Abstract

Disclosed are an R-T-B-based permanent magnet material, a preparation method therefor and the use thereof. The R-T-B-based permanent magnet material I comprises the following components: 29.0-32.5% of R including RH, 0.30 to 0.50 wt. % of Cu, 0.05 to 0.20 wt. % of Ti, 0.85 to 1.05 wt. % of B, 0.1 to 0.3 wt. % of C, 66 to 68 wt. % of Fe, wherein R is a rare earth element and R at least includes Nd; and RH is a heavy rare earth element and RH at least includes Tb or Dy, A Cu—Ti—C grain boundary phase is formed in the R-T-B-based permanent magnet material I, and Hcj is significantly improved.

Claims

1. An R-T-B-based permanent magnet material I, wherein, the R-T-B-based permanent magnet material I comprises the following components by mass percentage: 29.0-32.5 wt. % of R, and R includes RH; 0.30-0.50 wt. % of Cu; 0.05-0.20 wt. % of Ti; 0.85-1.05 wt. % of B; 0.1-0.3 wt. % of C; 66-68 wt. % of Fe, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material I; R is a rare earth element, and the R at least includes Nd; RH is a heavy rare earth element, and RH at least includes Tb and/or Dy.

2-10. (canceled)

11. The R-T-B-based permanent magnet material I according to claim 1, wherein, the R-T-B-based permanent magnet material I has Cu—Ti—C grain boundary phase at the grain boundary of the magnet; and, the R-T-B-based permanent magnet material I comprises: 0-0.15 wt. % of O, but not 0, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material I; and, the R-T-B-based permanent magnet material I further comprises: 0-3 wt. % of M, the kind of M comprises at least one element in the group consisting of Co, Al, Ga, Si, Sn, Ge, Ag, Au, Bi, Mn and Cr.

12. The R-T-B-based permanent magnet material I according to claim 11, wherein, the kind of M is Co or Ga.

13. The R-T-B-based permanent magnet material I according to claim 11, wherein, the content of O is 0.04-0.12 wt. %.

14. The R-T-B-based permanent magnet material I according to claim 11, wherein, the M comprises Co, the content of Co is 0.5-1.5 wt. %; or, the M comprises Ga, the content of Ga is 0.2-0.5 wt. %.

15. The R-T-B-based permanent magnet material I according to claim 1, wherein, R comprises Pr.

16. The R-T-B-based permanent magnet material I according to claim 1, wherein, the content of R is 30-32.5 wt. %, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material I; or, the content of RH is 0.5-1.2 wt. %, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material I; or, the content of Cu is 0.3-0.45 wt. % or 0.5 wt. %, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material I; or, the Ti content is 0.05-0.2 wt. %, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material I; or, the content of B is 0.9-1.0 wt. %, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material I; or, the content of C is 0.1-0.2 wt. %, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material I.

17. A use of the R-T-B-based permanent magnet material as electronic components, wherein, the R-T-B-based permanent magnet material is the R-T-B-based permanent magnet material I according to claim 1.

18. An R-T-B-based permanent magnet material II, wherein, the R-T-B-based permanent magnet material II comprises the following components by mass percentage: 29.0-32 wt. % of R, and R includes RH, the content of RH is 0-0.5 wt. %; 0.30-0.50 wt. % of Cu; 0.05-0.20 wt. % of Ti; 0.1-0.3 wt. % of C; 0.85-1.05 wt. % of B; 66-68 wt. % of Fe, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material II; R is a rare earth element, and the R comprises at least Nd; RH is a heavy rare earth element, and the RH comprises at least Tb and/or Dy.

19. The R-T-B-based permanent magnet material II according to claim 18, wherein, R further comprises Pr.

20. The R-T-B-based permanent magnet material II according to claim 18, wherein, the content of R is 29.5-31.5 wt. %, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material II; or, the content of Cu is 0.3-0.45 wt. % or 0.5 wt. %, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material II; or, the content of Ti is 0.05-0.2 wt. %, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material II; or, the content of B is 0.9-1.0 wt. %, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material II; or, the content of C is 0.1-0.2 wt. %, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material II.

21. The R-T-B-based permanent magnet material II according to claim 18, wherein, the R-T-B-based permanent magnet material II further comprises: 0-0.15 wt. % of O, but not 0; wt. % refers to the mass percentage in the R-T-B-based permanent magnet material II; and, the R-T-B-based permanent magnet material II further comprises: 0-3 wt. % of M, and the M comprises at least one element in the group consisting of Co, Al, Ga, Si, Sn, Ge, Ag, Au, Bi, Mn and Cr.

22. The R-T-B-based permanent magnet material II according to claim 18, wherein, the content of O is 0.04-0.12 wt. %, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material II.

23. The R-T-B-based permanent magnet material II according to claim 18, wherein, the M comprises Co, the content of Co is 0.5-1.5 wt. %, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material II; or, the M comprises Ga, the content of Ga is 0.2-0.5 wt. %, wt. % refers to the mass percentage in the R-T-B-based permanent magnet material II.

24. A use of the R-T-B-based permanent magnet material as electronic components, wherein, the R-T-B-based permanent magnet material is the R-T-B-based permanent magnet material II according to claim 18.

25. A preparation method for R-T-B-based permanent magnet material I, wherein, the R-T-B-based permanent magnet material II according to claim 18 is subjected to grain boundary diffusion treatment; the heavy rare earth elements in the grain boundary diffusion treatment comprise Tb and/or Dy.

26. An R-T-B-based permanent magnet material I prepared by the preparation method according to claim 25.

27. A preparation method for R-T-B-based permanent magnet material II, wherein, the preparation method comprises the following steps: the molten liquid of the raw material composition of the R-T-B-based permanent magnet material II is subjected to casting, decrepitation, pulverization, forming and sintering; wherein: the raw material composition of the R-T-B-based permanent magnet material II comprises the following components by mass percentage: 29.0-32 wt. % of R, and R comprises RH, the content of RH is 0-0.5 wt. %; 0.30-0.50 wt. % of Cu; 0.05-0.20 wt. % of Ti; 0.85-1.05 wt. % of B; 66-68 wt. % of Fe; R is a rare earth element, and the R comprises at least Nd; RH is a heavy rare earth element, the RH comprises at least Tb or Dy.

28. The preparation method for R-T-B-based permanent magnet material II according to claim 27, wherein, the process of the pulverization is carried out in an atmosphere with oxidized gas of 100 ppm or less.

29. An R-T-B-based permanent magnet material II prepared by the preparation method for R-T-B-based permanent magnet material II according to claim 27.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0106] FIG. 1 is the distribution diagram of Nd, Cu, Ti and C formed by FE-EPMA face scanning of R-T-B-based permanent magnet materials prepared in Embodiment 2, wherein, the point I is the Cu—Ti—C phase.

[0107] FIG. 2 is the distribution diagram of Nd, Cu, Ti and. C formed by FE-EPMA face scanning of R-T-B-based permanent magnet materials prepared in Comparative embodiment 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0108] The following embodiments further illustrate the present disclosure, but the present disclosure is not limited thereto. Experimental methods for which specific conditions are not specified in the following embodiments shall be selected in accordance with conventional methods and conditions, or in accordance with the commodity description. In the following table, wt. % refers to the mass percentage of the component in the raw material composition of the neodymium-iron-boron magnet material, and “/” means that the element is not added. “Br” refers to remanence, and “Hcj” refers to intrinsic coercivity.

[0109] The formulas of R-T-B-based permanent magnet material II of the embodiments and comparative embodiments are shown in Table 1.

TABLE-US-00001 TABLE 1 Components and content of the raw material composition of R-T-B-based permanent magnet material II (wt. %) No. R Nd Pr Nd Tb Dy Cu Ti B Co Ga Fe Embodiment 1 31.0 31.0 / / / 0.50 0.05 0.86 0.50 0.30 remainder Embodiment 2 30.5 30.5 / / / 0.40 0.15 0.90 0.60 0.40 remainder Embodiment 3 31.5 31.5 / / / 0.35 0.10 0.92 0.70 0.50 remainder Embodiment 4 30.5 30.5 / / / 0.40 0.15 0.92 1.00 0.50 remainder Embodiment 5 30.5 / / / / 0.40 0.15 0.90 0.50 0.40 remainder Embodiment 6 30.5 30.5 30.5 / / 0.40 0.15 0.90 0.50 0.40 remainder Embodiment 7 30.0 29.0 / / 0.5 0.30 0.15 0.94 1.00 / remainder Embodiment 8 30.5 30.0 / / 0.5 0.45 0.20 0.96 1.00 / remainder Embodiment 9 29.5 29.0 / / 0.5 0.50 0.15 0.98 1.00 / remainder Embodiment 10 29.5 29.0 / / 0.5 0.40 0.15 1.00 1.20 / remainder Comparative 30.5 30.5 / / / 0.60 0.15 0.90 0.60 0.40 remainder Embodiment 1 Comparative 30.5 30.5 / / / 0.20 0.20 0.92 0.60 0.40 remainder Embodiment 2 Comparative 29.5 29.0 / 0.5 / 0.45 0.02 0.95 1.20 / remainder Embodiment 3 Comparative 29.5 29.0 / 0.5 / 0.30 0.30 1.00 1.20 / remainder Embodiment 4 Comparative 30.0 29.5 / 0.5 / 0.40 0.10 0.95 1.00 / remainder Embodiment 5 Comparative 30.0 29.5 / 0.5 / 0.40 0.10 0.95 1.00 / remainder Embodiment 6 Comparative 30.5 30.5 / / / 0.60 0.10 0.92 0.50 0.50 remainder Embodiment 7 Comparative 30.0 29.5 / 0.5 / 0.40 0.25 0.95 1.00 / remainder Embodiment 8 Comparative 30.0 29.5 / 0.5 / 0.020 0.25 0.95 1.00 / remainder Embodiment 9 Comparative 30.5 30.5 / / / 0.60 0.25 0.90 0.50 0.40 remainder Embodiment 10

TABLE-US-00002 TABLE 2 Components and content of R-T-B-based permanent magnet material II (wt. %) No. R Nd Pr Nd Tb Dy Cu Ti B O Co Ga Fe Embodiment 1 31.0 31.0 / / / 0.50 0.05 0.86 0.05 0.50 0.30 remainder Embodiment 2 30.5 30.5 / / / 0.40 0.15 0.90 0.08 0.60 0.40 remainder Embodiment 3 31.5 31.5 / / / 0.35 0.10 0.92 0.10 0.70 0.50 remainder Embodiment 4 30.5 30.5 / / / 0.40 0.15 0.92 0.13 1.00 0.50 remainder Embodiment 5 30.5 / 30.5 / / 0.40 0.15 0.90 0.08 0.50 0.40 remainder Embodiment 6 30.5 30.5 / / / 0.40 0.15 0.90 0.08 0.50 0.40 remainder Embodiment 7 30.0 29.5 / 0.5 / 0.30 0.15 0.94 0.08 1.00 / remainder Embodiment 8 30.5 30.0 / 0.5 / 0.45 0.20 0.96 0.06 1.00 / remainder Embodiment 9 29.5 29.0 / 0.5 / 0.50 0.10 0.98 0.12 1.20 / remainder Embodiment 10 29.5 29.0 / 0.5 / 0.40 0.15 1.00 0.15 1.00 / remainder Comparative 30.5 30.5 / / / 0.60 0.15 0.90 0.10 0.60 0.40 remainder Embodiment 1 Comparative 30.5 30.5 / / / 0.20 0.20 0.92 0.10 0.60 0.40 remainder Embodiment 2 Comparative 29.5 29.0 / 0.5 / 0.45 0.02 0.95 0.10 1.20 / remainder Embodiment 3 Comparative 29.5 29.0 / 0.5 / 0.30 0.30 1.00 0.10 1.20 / remainder Embodiment 4 Comparative 30.0 29.5 / 0.5 / 0.40 0.10 0.95 0.10 1.00 / remainder Embodiment 5 Comparative 30.0 29.5 / 0.5 / 0.40 0.10 0.95 0.10 1.00 / remainder Embodiment 6 Comparative 30.5 30.5 / / / 0.60 0.10 0.92 0.10 0.50 0.50 remainder Embodiment 7 Comparative 30.0 29.5 / 0.5 / 0.40 0.25 0.95 0.10 1.00 / remainder Embodiment 8 Comparative 30.0 29.5 / 0.5 / 0.20 0.25 0.95 0.10 1.00 / remainder Embodiment 9 Comparative 30.5 30.5 / / / 0.60 0.25 0.90 0.10 0.50 0.40 remainder Embodiment 10

[0110] The preparation method for the R-T-B-based permanent magnet material in Embodiments 1-5 and 7-10, and Comparative Embodiments 1-9 is as follows:

[0111] (1) Melting process: according to the formulas shown in Table 1, the pre-made raw materials were put into the crucible made of aluminum oxide, and were vacuum melted in the high frequency vacuum induction melting furnace and in a vacuum of 5×10.sup.−2 Pa at a temperature of 1500° C. or less.

[0112] (2) Casting process: Ar gas was introduced into the melting furnace after vacuum melting to make the air pressure reach 55,000 Pa, and then casting was carried out, and quenching alloy was obtained at the cooling rate of 10.sup.2° C./s to 10.sup.4° C./s,

[0113] (3) Hydrogen decrepitation process: the hydrogen decrepitation furnace with quench alloy placed therein was vacuumed at room temperature, and then hydrogen with a purity of 99.9% was introduced into the hydrogen decrepitation furnace, to maintain the hydrogen pressure at 0.15 MPa; after full hydrogen absorption, the temperature was raised while vacuuming for full dehydrogenation; then cooled, and took out the powder obtained from hydrogen decrepitation,

[0114] (4) Micro-pulverization process: In nitrogen atmosphere with the content of oxidizing gas of 100 ppm or less and under the condition of a pressure of 0.38 MPa in the pulverization chamber, the powder obtained from hydrogen decrepitation was pulverized by jet mill pulverization for 3 hours to obtain fine powder. The oxidizing gas refers to oxygen or water.

[0115] (5) The zinc stearate was added to the powder obtained from jet mill pulverization, the addition amount of zinc stearate was 0.12% by weight of mixed powder, and then mixed fully by v-type mixer.

[0116] (6) Magnetic field forming process: The rectangular oriented magnetic field forming machine was used to form the above powder with zinc stearate into a cube with sides of 25 mm in a oriented magnetic field of 1.6 T and under the molding pressure of 0.35 ton/cm.sup.2; demagnetization was carried out in a magnetic field of 0.2 T after forming. In order to prevent the formed body after the first forming from contacting the air, it was sealed, and then the secondary forming was carried out with the secondary forming machine (isostatic pressing machine) under the pressure of 1.3 ton/cm.sup.2.

[0117] (7) Sintering process: each formed body was moved to the sintering furnace for sintering, sintered in the vacuum of 5×10.sup.−3 Pa and at 300° C. and 600° C. for 1 hour respectively; then sintered at the temperature of 1050° C. for 2 hours; Ar was then introduced to make the air pressure reach 0.1 MPa and then cooled to room temperature, to obtain the R-T-B-based permanent magnet material II.

[0118] (8) Grain boundary diffusion treatment process: The sintered body was processed into the magnet with a diameter of 20 mm, and a thickness of 3 mm, the direction of the thickness was the direction of magnetic field orientation, after the surface was cleaned, the raw material prepared with Tb fluoride was coated on the magnet through fully spraying respectively, after drying the coated magnet, the metal attached with Dy was sputtered on the surface of the magnet in the high purity Ar atmosphere, and diffusing heat treatment was carried out at 850° C. for 24 hours. Cooled to room temperature.

[0119] (9) Heat treatment process: The sintered body was heated at 500° C. for 3 hours in the Ar of high purity, cooled to room temperature and taken out to obtain the R-T-B-based permanent magnet material I.

[0120] The preparation method for R-T-B-based permanent magnet materials in Embodiment 6 and Comparative Embodiment 10 is as follows:

[0121] The R-T-B-based permanent magnet materials in Embodiment 6 and Comparative embodiment 10 were prepared, according to the formulas as shown in Table 1, and the preparation process in Embodiment 1, the difference is: the metal attached with Dy was sputtered on the surface of the magnet in the process of grain boundary diffusion.

Effect Embodiment

[0122] The magnetic properties and components of RTB-based permanent magnet materials prepared in Embodiments 1-10 and Comparative embodiments 1-10 were determined respectively, which include the permanent magnetic materials before grain boundary diffusion (R-T-B-based permanent magnet material II) and the permanent magnetic materials after grain boundary diffusion (R-T-B-based permanent magnet material I), and the crystal phase structure of the magnets was observed by FE-EPMA.

[0123] (1) Evaluation of magnetic properties: The NIM-10000H BH bulk rare earth permanent magnetic nondestructive measurement system in National Institute of Metrology, China was used for magnetic properties detection of permanent magnetic materials. The detection results of magnetic properties are shown in Table 3 below.

TABLE-US-00003 TABLE 3 Detection results of magnetic properties R-T-B-based R-T-B-based permanent permanent magnet material II magnet material I Hcj Hjc ΔHcj No. Br(T) (kA/m) Br(T) (kA/m) (kA/m) Embodiment 1 1.421 860 1.412 1966 1106 Embodiment 2 1.429 852 1.415 2006 1154 Embodiment 3 1.437 820 1.423 1982 1162 Embodiment 4 1.430 860 1.424 1942 1083 Embodiment 5 1.420 884 1.413 1966 1083 Embodiment 6 1.428 892 1.417 1775 884 Embodiment 7 1.450 931 1.438 2086 1154 Embodiment 8 1.441 947 1.432 2078 1130 Embodiment 9 1.442 955 1.431 2101 1146 Embodiment 10 1.438 931 1.429 1918 987 Comparative 1.404 852 1.390 1508 656 Embodiment 1 Comparative 1.435 844 1.422 1506 662 Embodiment 2 Comparative 1.435 939 1.426 1592 653 Embodiment 3 Comparative 1.434 931 1.421 1576 645 Embodiment 4 Comparative 1.433 923 1.421 1588 665 Embodiment 5 Comparative 1.450 1122 1.440 1910 788 Embodiment 6 Comparative 1.403 836 1.392 1493 657 Embodiment 7 Comparative 1.440 1051 1.429 1839 788 Embodiment 8 Comparative 1.425 876 1.413 1520 645 Embodiment 9 Comparative 1.405 844 1.391 1329 486 Embodiment 10
Table 3 shows that:

[0124] 1) The R-T-B-based permanent magnet materials in this application have excellent performance, with Br1.4T and Hcj increased from 820 kA/m before diffusion to 1775 kA/m after diffusion, realizing double improvement of Hcj (Embodiments 1-10);

[0125] 2) Cu—Ti—C phase cannot be formed or the proportion of the formed Cu—Ti—C phase was very little if the amounts of Cu, Ti and C in raw materials were changed on the basis of the formulas of this application, and the performance of R-T-B-based permanent magnet materials decreased significantly (Comparative Embodiments 1-10);

[0126] 3) During the process of research the inventor found that, the higher content of O added was not conducive to the formation of Cu—Ti—C phase, and the magnetic properties tended to decrease (Embodiments 10).

[0127] (2) Component determination: The components of R-T-B-based permanent magnet material I were determined by the high frequency inductively coupled plasma emission spectrometer (ICP-OES). Table 4 below shows the test results of the components.

TABLE-US-00004 TABLE 4 Components and content of R-T-B-based permanent magnet material I No. R Nd PrNd Tb Dy Cu Ti B C 0 Co C3a Fe Embodiment 1 31.6 31.0 / 0.6 / 0.50 0.05 0.86 0.10 0.05 0.50 0.30 remainder Embodiment 2 31.1 30.5 / 0.6 / 0.40 0.15 0.90 0.14 0.08 0.60 0.40 remainder Embodiment 3 32.1 31.5 / 0.6 / 0.35 0.10 0.92 0.16 0.10 0.70 0.50 remainder Embodiment 4 31.1 30.5 / 0.6 / 0.40 0.15 0.92 0.12 0.13 1.00 0.50 remainder Embodiment 5 31.1 / 30.5 0.6 / 0.40 0.15 0.90 0.10 0.08 0.50 0.40 remainder Embodiment 6 31.1 30.5 / / 0.6 0.40 0.15 0.90 0.10 0.08 0.50 0.40 remainder Embodiment 7 30.6 29.5 / 1.1 / 0.30 0.15 0.94 0.12 0.08 1.00 / remainder Embodiment 8 31.1 30.0 / 1.1 / 0.45 0.20 0.96 0.18 0.06 1.00 / remainder Embodiment 9 30.1 29.0 / 1.1 / 0.50 0.10 0.98 0.14 0.12 1.20 / remainder Embodiment 10 30.1 29.0 / 1.1 / 0.40 0.15 1.00 0.20 0.15 1.00 / remainder Comparative 31.1 30.5 / 0.6 / 0.60 0.15 0.90 0.20 0.10 0.60 0.40 remainder Embodiment 1 Comparative 31.1 30.5 / 0.6 / 0.20 0.20 0.92 0.15 0.10 0.60 0.40 remainder Embodiment 2 Comparative 30.1 29.0 / 1.1 / 0.45 0.02 0.95 0.10 0.10 1.20 / remainder Embodiment 3 Comparative 30.1 29.0 / 1.1 / 0.30 0.30 1.00 0.10 0.10 1.20 / remainder Embodiment 4 Comparative 30.6 29.5 / 1.1 / 0.40 0.10 0.95 0.10 0.10 1.00 / remainder Embodiment 5 Comparative 30.6 29.5 / 1.1 / 0.40 0.10 0.95 0.10 0.10 1.00 / remainder Embodiment 6 Comparative 31.1 30.5 / 0.6 / 0.60 0.10 0.92 0.10 0.10 0.50 0.50 remainder Embodiment 7 Comparative 30.6 29.5 / 1.1 / 0.40 0.25 0.95 0.10 0.10 1.00 / remainder Embodiment 8 Comparative 30.6 29.5 / 1.1 / 0.20 0.25 0.95 0.10 0.10 1.00 / remainder Embodiment 9 Comparative 31.1 30.5 / / 0.6 0.60 0.25 0.90 0.10 0.10 0.50 0.40 remainder Embodiment 10

[0128] (3) FE-EPMA detection: The vertical orientation surface of the permanent magnet material was polished, and detected using the Field emission electron probe micro-analyzer (FE-EPMA) (JEOL, 8530F). The R-T-B-based permanent magnet material I in Embodiment 2 and Comparative. Embodiment 2 were detected by FE-EPMA, there is a grain boundary phase at the corresponding point 1 in FIG. 1 at the grain boundary of the R-T-B-based permanent magnet material I in Embodiment 2; there is a grain boundary phase at the corresponding point 2 in FIG. 2 at the grain boundary of the R-T-B-based permanent magnet material I in Comparative Embodiment 2.