RTB-Based Permanent Magnet Material, Preparation Method thereof, and Application thereof

Abstract

An RIB-based permanent magnet material, a preparation method thereof, and an application thereof. The RIB-based permanent magnet material comprises the following components: R′: 29.5 to 33.5 wt. %, wherein R′ comprises Pr, and the content of Pr is ≥8.85 wt. %; C:0.106 to 0.26 wt. %; O: ≤0.07 wt. %; X: 0 to 5.0 wt. %, wherein X is one or more of Cu, Al, Ga, Co, Zr, Ti, Nb and Mn; B:0.90 to 1.2 wt. %; and Fe:61.4 to 69.5 wt. %. The RIB-based permanent magnet material can improve the performance of a permanent magnet material without employing heavy rare earths. There is no need to control the content of carbon introduced in the process, and the magnet exhibits excellent performance even with a high carbon content.

Claims

1. A RTB-based permanent magnet material, wherein, the RTB-based permanent magnet material comprises the following components by mass percentage: R′: 29.5-33.5 wt. %, wherein: R′ is a rare earth element and R′ comprises Pr; the content of Pr is ≥8.85 wt. %; C: 0.106-0.26 wt. %; O: ≤0.07 wt. %; X: 0-5.0 wt. %, X is one or more of Cu, Al, Ga, Co, Zr, Ti, Nb and Mn; B: 0.90-1.2 wt. %; Fe: 61.4-69.5 wt. %.

2-10. (canceled)

11. The RTB-based permanent magnet material according to claim 1, wherein, the RTB-based permanent magnet material includes a main phase, a grain boundary phase, and an intergranular triangle region, and the percentage of the volume of the intergranular triangle region to the sum of the volume of the “main phase, the grain boundary phase and the intergranular triangle region” is ≤9.0%.

12. The RTB-based permanent magnet material according to claim 1, wherein, R′ further comprises Nd; or, R′ further comprises R, R is a rare earth element besides Pr and Nd.

13. The RTB-based permanent magnet material according to claim 1, wherein, R′ also comprises a heavy rare earth element RH; wherein, the kind of RH is selected from the group consisting of Dy and Tb.

14. The RTB-based permanent magnet material according to claim 1, wherein, the RTB-based permanent magnet material further comprises M, and M is one or more of Ni, Zn, Ag, In, Sn, Bi, V, Cr, Hf, Ta, and W; the content of M is 0-0.15 wt. %, but not 0, the percentage refers to the mass percentage in the RTB-based permanent magnet material.

15. The RTB-based permanent magnet material according to claim 1, wherein, the RTB-based permanent magnet material further comprises nitrogen element N, the content of N≤0.05 wt. %, the percentage refers to the mass percentage in the RTB-based permanent magnet material.

16. The RTB-based permanent magnet material according to claim 1, wherein, X is Cu, Al, Ga, Co, Zr, Ti or Nb, or “Cu and Al”, “Ga and Mn”, “Cu, Al and Ga”, “Cu, Al, Ga and Zr”, “Cu, Al, Ga and Co” or “Cu, Al, Ga, Zr and Co”.

17. The RTB-based permanent magnet material according to claim 1, wherein, the RTB-based permanent magnet material comprises the following components: R′: 29.5-33.5 wt. %, Pr≥8.85 wt. %, C: 0.106-0.25 wt. %, O: ≤0.07 wt. %, B: 0.94-1.1 wt. %, Fe: 61.4-69.3 wt. %, the percentage refers to the mass percentage in the RTB-based permanent magnet material; or, the RTB-based permanent magnet material comprises the following components: R′: 29.5-33.5 wt. %, Pr≥8.85 wt. %, C: 0.106-0.25 wt. %, O: ≤0.07 wt. %, Cu: 0.2-0.51 wt. %, B: 0.94-1.1 wt. %, Fe: 61.4-69.3 wt. %, the percentage refers to the mass percentage in the RTB-based permanent magnet material; or, the RTB-based permanent magnet material comprises the following components: R′: 29.5-33.5 wt. %, Pr≥8.85 wt. %, C: 0.106-0.25 wt. %, O: ≤0.07 wt. %, Al: 0-0.81 wt. %, but not 0, B: 0.94-1.1 wt. %, Fe: 61.4-69.3 wt. %, the percentage refers to the mass percentage in the RTB-based permanent magnet material; or, the RTB-based permanent magnet material comprises the following components: R′: 29.5-33.5 wt. %, Pr≥8.85 wt. %, C:0.106-0.25 wt. %, O: ≤0.07 wt. %, Ga: 0.1-1.85 wt. %, B: 0.94-1.1 wt. %, Fe: 61.4-69.3 wt. %, the percentage refers to the mass percentage in the RTB-based permanent magnet material; or, the RTB-based permanent magnet material comprises the following components: R′: 29.5-33.5 wt. %, Pr≥8.85 wt. %, C: 0.106-0.25 wt. %, O: ≤0.07 wt. %, Co: 0.0-3.0 wt. %, but not 0, B: 0.94-1.1 wt. %, Fe: 61.4-69.3 wt. %, the percentage refers to the mass percentage in the RTB-based permanent magnet material; or, the RTB-based permanent magnet material comprises the following components: R′: 29.5-33.5 wt. %, Pr≥8.85 wt. %, C:0.106-0.25 wt. %, O: ≤0.07 wt. %, Zr: 0.25-0.35 wt. %, B: 0.94-1.1 wt. %, Fe: 61.4-69.3 wt. %, the percentage refers to the mass percentage in the RTB-based permanent magnet material; or, the RTB-based permanent magnet material comprises the following components: R′: 29.5-33.5 wt. %, Pr≥8.85 wt. %, C: 0.106-0.25 wt. %, O: ≤0.07 wt. %, Nb: 0.25-0.35 wt. %, B: 0.94-1.1 wt. %, Fe: 61.4-69.3 wt. %, the percentage refers to the mass percentage in the RTB-based permanent magnet material; or, the RTB-based permanent magnet material comprises the following components: R′: 29.5-33.5 wt. %, Pr≥8.85 wt. %, C: 0.106-0.25 wt. %, O: ≤0.07 wt. %, Cu: 0.34-0.51 wt. %, Al: 0-0.81 wt. %, but not 0, B: 0.94-1.1 wt. %, Fe: 61.4-69.3 wt. %, the percentage refers to the mass percentage in the RTB-based permanent magnet material; or, the RTB-based permanent magnet material comprises the following components: R′: 29.5-33.5 wt. %, Pr≥8.85 wt. %, C: 0.106-0.25 wt. %, O: ≤0.07 wt. %, Cu: 0.34-0.51 wt. %, Al: 0-0.81 wt. %, but not 0, Ga: 0.1-0.5 wt. %, B: 0.94-1.1 wt. %, Fe: 61.4-69.3 wt. %, the percentage refers to the mass percentage in the RTB-based permanent magnet material; or, the RTB-based permanent magnet material comprises the following components: R′: 29.5-33.5 wt. %, Pr≥8.85 wt. %, C: 0.106-0.25 wt. %, O: ≤0.07 wt. %, Cu: 0.34-0.51 wt. %, Al: 0.25-0.81 wt. %, Ga: 0.1-0.42 wt. %, Zr: 0.25-0.30 wt. %, B: 0.94-1.1 wt. %, Fe: 61.4-69.3 wt. %, the percentage refers to the mass percentage in the RTB-based permanent magnet material; or, the RTB-based permanent magnet material comprises the following components: R′: 29.5-33.5 wt. %, Pr≥8.85 wt. %, C:0.106-0.25 wt. %, O: ≤0.07 wt. %, Cu: 0.34-0.51 wt. %, Al: 0.25-0.81 wt. %, Ga: 0.1-0.41 wt. %, Co: 0.0-3.0 wt. %, Zr: 0.25-0.30 wt. %, Cr: 0.05-0.12 wt. %, B: 0.94-1.1 wt. %, Fe: 61.4-69.3 wt. %, the percentage refers to the mass percentage in the RTB-based permanent magnet material; or, the RTB-based permanent magnet material comprises the following components: R′: 29.5-33.5 wt. %, Pr≥8.85 wt. %, RH: 0.5-2.6 wt. %, C: 0.106-0.25 wt. %, O: ≤0.07 wt. %, Cu: 0.34-0.51 wt. %, Al: 0.25-0.81 wt. %, Ga: 0.1-0.41 wt. %, Co: 0.0-3.0 wt. %, Zr: 0.25-0.30 wt. %, B: 0.94-1.1 wt. %, Fe: 61.4-69.3 wt. %, the percentage refers to the mass percentage in the RTB-based permanent magnet material; or, the RTB-based permanent magnet material comprises the following components: R′: 29.5-33.5 wt. %, Pr≥8.85 wt. %, Ce: 0-1 wt. %, RH: 0.5-2.6 wt. %, C: 0.106-0.25 wt. %, O: ≤0.07 wt. %, Cu: 0.34-0.51 wt. %, Al: 0.25-0.81 wt. %, Ga: 0.1-0.41 wt. %, Co: 0.0-3.0 wt. %, Zr: 0.25-0.30 wt. %, B: 0.94-1.1 wt. %, Fe: 61.4-69.3 wt. %, the percentage refers to the mass percentage in the RTB-based permanent magnet material.

18. An application of the RTB-based permanent magnet material according to claim 1 as electronic components.

19. A preparation method for RTB-based permanent magnet material, wherein, the preparation method comprises the following steps: the molten liquid of the raw material composition of the RTB-based permanent magnet material is subjected to casting, hydrogen decrepitation and pulverization to obtain a powder, and the powder is mixed with dispersant, and then pressed, formed, sintered and aged; wherein: (1) the raw material composition of RTB-based permanent magnet material comprises the following components by mass percentage: R′: 29.5-33.5 wt. %, R′ is a rare earth element, R′ comprises Pr, the content oo Pr is ≥8.85 wt. %; X: 0-5.0 wt. %, X is one or more of Cu, Al, Ga, Co, Zr, Ti, Nb and Mn; B: 0.90-1.2 wt. %; Fe: 61.4-69.5 wt. %; (2) in the process of pulverization, O≤60 ppm in the pulverization atmosphere; (3) in the pressing process, O≤40 ppm in the pressing atmosphere; (4) the dispersant comprises element C, and the mass percentage of the dispersant in the mixed powder is 0.04-0.2%.

20. The preparation method of RTB-based permanent magnet material according to claim 19, wherein, R′ further comprises Nd; or R′ further comprises R, R is a rare earth element besides Pr and Nd.

21. The preparation method of RTB-based permanent magnet material according to claim 19, wherein, R′ further comprises a heavy rare earth element RH; the kind of RH is selected from the group consisting of Dy and Tb.

22. The preparation method of RTB-based permanent magnet material according to claim 19, wherein, X is Cu, Al, Ga, Co, Zr, Ti or Nb, or, “Cu and Al”, “Ga and Mn”, “Cu, Al and Ga”, “Cu, Al, Ga and Zr”, “Cu, Al, Ga and Co” or “Cu, Al, Ga, Zr and Co”.

23. The preparation method of RTB-based permanent magnet material according to claim 19, wherein, when X comprises Cu, the content of the Cu is 0.2-0.5 wt. %; or, when the X comprises Al, the content of Al is 0-0.8 wt. %, but not 0; or, when the X comprises Ga, the content of Ga is 0.0-1.85 wt. %, but not 0; or, when the X comprises Co, the content of Co is 0.0-3.0 wt. %, but not 0; or, when the X comprises Zr, the content of Zr is 0.25-0.35 wt. %; or, when the X comprises Nb, the content of Nb is 0.25-0.35 wt. %; or, when the X comprises Mn, the content of Mn is 0.0-0.03 wt. %, but not 0; the percentage refers to the mass percentage in the raw material composition of the RTB-based permanent magnet material.

24. The preparation method of RTB-based permanent magnet material according to claim 19, wherein, the RTB-based permanent magnet material further comprises M, M is one or more of Ni, Zn, Ag, In, Sn, Bi, V, Cr, Hf, Ta and W; the content of M is 0-0.15 wt. %, but not 0, and the percentage refers to the mass percentage in the raw material composition of the RTB-based permanent magnet material.

25. The preparation method of RTB-based permanent magnet material according to claim 19, wherein, the molten liquid of the raw material composition of the RTB-based permanent magnet material is prepared by the following method: melting in a vacuum induction melting furnace; the vacuum degree of the melting furnace is 5×10.sup.−2 Pa; the melting temperature is below 1500° C.; or, the casting process is carried out as follows: cooling at a rate of 10.sup.2° C./s-10.sup.4° C./s in an Ar atmosphere; or, the pulverization is jet mill pulverization; or, the sintering is also preceded by preheating; or, the temperature of the sintering is 1040-1090° C.; or, the treatment temperature of the aging treatment is 500-650° C.; or, in the aging treatment, the heating rate of heating to 500-650° C. is 3-5° C./min.

26. The preparation method of RTB-based permanent magnet material according to claim 19, wherein, the grain boundary diffusion treatment is also carried out after sintering and before the aging treatment; wherein, the grain boundary diffusion treatment is carried out according to the following steps, attaching substance containing Tb, Dy, or “Tb and Dy” to the surface of the RTB-based permanent magnet material by evaporating, coating or sputtering, then carrying out diffusion heat treatment.

27. The preparation method of RTB-based permanent magnet material according to claim 19, wherein, during the process of pulverization, the content of oxygen O in the pulverization atmosphere is 0-50 ppm; or, the dispersant is selected from the group consisting of a lubricant and an antioxidant; or, the content of the dispersant is 0.04-0.14%, the percentage refers to the mass percentage with respect to the total mass of the mixed powder; or, during the pressing process, the content of oxygen O in the pressing atmosphere is 10-30 ppm.

28. A RTB-based permanent magnet material prepared by the preparation method of RTB-based permanent magnet material according to claim 19.

29. An application of the RTB-based permanent magnet material according to claim 28 as electronic components.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0142] FIG. 1 is the microstructure scanning photo of the RTB-based permanent magnet mater prepared in embodiment 68, wherein, the position referred to by a is the intergranular triangle region.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0143] The following examples 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 percentage by mass of the component in the raw material composition of the RTB-based permanent magnet material, and “/” means that the element is not added. “Br” refers to remanence, and “Hcj” refers to intrinsic coercivity.

[0144] The formulas of RTB-based permanent magnet materials of the embodiments and comparative embodiments are shown in Table 1.

TABLE-US-00001 TABLE 1 R Nd Pr RH Cu Ga Co Zr Nb Mn M B R con- wt. wt. RH wt. wt. Al wt. wt. wt. wt. wt. M wt. wt. Fe No. kind tent % % kind % % wt. % % % % % % kind % % wt. % Embodi- / / 21.65 8.85 / / / / / / / / / / / 0.95 remainder ment 1 Embodi- / / 19.65 10.85 / / / / / / / / / / / 0.95 remainder ment 2 Embodi- / / 18.35 12.15 / / / / / / / / / / / 0.95 remainder ment 3 Embodi- / / 16.35 14.15 / / / / / / / / / / / 0.95 remainder ment 4 Embodi- / / 14.35 16.15 / / / / / / / / / / / 0.95 remainder ment 5 Embodi- / / 13.35 17.15 / / / / / / / / / / / 0.95 remainder ment 6 Embodi- / / 11.35 19.15 / / / / / / / / / / / 0.95 remainder ment 7 Embodi- / / 9.35 21.15 / / / / / / / / / / / 0.95 remainder ment 8 Embodi- / / 7.35 23.15 / / / / / / / / / / / 0.95 remainder ment 9 Embodi- / / 5.35 25.15 / / / / / / / / / / / 0.95 remainder ment 10 Embodi- / / 3.35 27.15 / / / / / / / / / / / 0.95 remainder ment 11 Embodi- / / 22.15 8.85 / / 0.20 / / / / / / / / 0.95 remainder ment 12 Embodi- / / 18.85 12.15 / / 0.30 / / / / / / / / 1.01 remainder ment 13 Embodi- / / 13.85 17.15 / / 0.35 / / / / / / / / 1.01 remainder ment 14 Embodi- / / 10.85 20.15 / / 0.45 / / / / / / / / 1.01 remainder ment 15 Embodi- / / 7.85 23.15 / / 0.50 / / / / / / / / 1.01 remainder ment 16 Embodi- / / 22.15 8.85 / / / 0.02 / / / / / / / 1.01 remainder ment 17 Embodi- / / 20.85 10.15 / / / 0.042 / / / / / / / 0.95 remainder ment 18 Embodi- / / 18.85 12.15 / / / 0.1 / / / / / / / 0.95 remainder ment 19 Embodi- / / 16.85 14.15 / / / 0.2 / / / / / / / 0.95 remainder ment 20 Embodi- / / 14.85 16.15 / / / 0.3 / / / / / / / 0.95 remainder ment 21 Embodi- / / 13.85 17.15 / / / 0.4 / / / / / / / 0.95 remainder ment 22 Embodi- / / 11.85 19.15 / / / 0.5 / / / / / / / 0.95 remainder ment 23 Embodi- / / 10.85 20.15 / / / 0.6 / / / / / / / 0.95 remainder ment 24 Embodi- / / 8.85 12.15 / / / 0.7 / / / / / / / 0.95 remainder ment 25 Embodi- / / 6.85 24.15 / / / 0.8 / / / / / / / 0.95 remainder ment 26 Embodi- / / 20.65 8.85 / / / / 0.1 / / / / / / 0.95 remainder ment 27 Embodi- / / 19.68 9.85 / / / / 0.2 / / / / / / 0.98 remainder ment 28 Embodi- / / 18.65 10.85 / / / / 0.25 / / / / / / 0.98 remainder ment 29 Embodi- / / 17.65 11.85 / / / / 0.30 / / / / / / 0.98 remainder ment 30 Embodi- / / 17.35 12.15 / / / / 0.42 / / / / / / 0.98 remainder ment 31 Embodi- / / 16.35 13.15 / / / / 0.50 / / / / / / 0.98 remainder ment 32 Embodi- / / 15.35 14.15 / / / / 0.90 / / / / / / 0.98 remainder ment 33 Embodi- / / 9.35 20.15 / / / / 1.40 / / / / / / 0.98 remainder ment 34 Embodi- / / 8.35 21.15 / / / / 1.55 / / / 0.01 / / 0.98 remainder ment 35 Embodi- / / 14.35 175 / / / / / 0.5 / / / / / 0.98 remainder ment 36 Embodi- / / 13.35 18.15 / / / / / 1 / / / / / 0.98 remainder ment 37 Embodi- / / 12.35 19.15 / / / / / 2.5 / / / / / 1.01 remainder ment 38 Embodi- / / 14.35 17.15 / / / / / / 0.25 / / / / 1.01 remainder ment 39 Embodi- / / 13.35 18.15 / / / / / / 0.30 / / / / 1.01 remainder ment 40 Embodi- / / 12.35 19.15 / / / / / / 0.35 / / / / 1.01 remainder ment 41 Embodi- / / 14.35 17.15 / / / / / / / 0.25 / / / 1.01 remainder ment 42 Embodi- / / 13.35 18.15 / / / / / / / 0.30 / / / 1.01 remainder ment 43 Embodi- / / 12.35 19.15 / / / / / / / 0.35 / / / 1.01 remainder ment 44 Embodi- / / 22.65 8.85 / / 0.34 0.02 / / / / / / / 1.01 remainder ment 45 Embodi- / / 21.35 10.15 / / 0.38 0.042 / / / / / / / 1.01 remainder ment 46 Embodi- / / 19.35 12.15 / / 0.42 0.1 / / / / / / / 1.01 remainder ment 47 Embodi- / / 17.35 14.15 / / 0.44 0.2 / / / / / / / 1.01 remainder ment 48 Embodi- / / 15.35 16.15 / / 0.50 0.3 / / / / / / / 1.01 remainder ment 49 Embodi- / / 14.35 17.15 / / 0.34 0.4 / / / / / / / 1.01 remainder ment 50 Embodi- / / 12.35 19.15 / / 0.35 0.5 / / / / / / / 1.01 remainder ment 51 Embodi- / / 11.35 20.15 / / 0.42 0.6 / / / / / / / 1.01 remainder ment 52 Embodi- / / 9.35 22.15 / / 0.34 0.5 0.1 / / / / / / 1.01 remainder ment 53 Embodi- / / 7.35 24.15 / / 0.40 0.6 0.3 / / / / / / 1.01 remainder ment 54 Embodi- / / 13.65 17.15 / / 0.50 0.8 0.42 / / / / / / 1.01 remainder ment 55 Embodi- / / 8.65 22.15 / / 0.34 0.5 0.1 / 0.25 / / / / 1.01 remainder ment 56 Embodi- / / 6.65 24.15 / / 0.50 0.8 0.3 / 0.30 / / / / 1.01 remainder ment 57 Embodi- / / 21.98 8.85 / / 0.34 0.01 0.25 / / / / / / 1.01 remainder ment 58 Embodi- / / 20.65 10.15 / / 0.38 0.02 0.30 / / / / / / 0.96 Remainder ment 59 Embodi- / / 18.65 12.15 / / 0.42 0.03 0.42 / / / / / / 0.96 remainder ment 60 Embodi- / / 16.65 14.15 / / 0.38 0.042 0.1 / / / / / / 0.96 remainder ment 61 Embodi- / / 14.65 16.15 / / 0.42 0.1 0.15 / / / / / / 0.96 remainder ment 62 Embodi- / / 13.65 17.15 / / 0.44 0.2 0.25 / / / / / / 0.96 remainder ment 63 Embodi- / / 11.65 19.15 / / 0.50 0.3 0.30 / / / / / / 0.96 remainder ment 64 Embodi- / / 10.65 20.15 / / 0.45 0.4 0.42 / / / / / / 0.96 remainder ment 65 Embodi- / / 8.65 22.15 / / 0.50 0.5 0.50 / / / / / / 1.01 remainder ment 66 Embodi- / / 12.65 18.15 / / 0.4 0.6 0.4 2.5 0.3 / / Cr 0.05 1.01 remainder ment 67 Embodi- / / 12.65 18.15 / / 0.4 0.6 0.4 2.5 0.3 / / Cr 0.12 1.01 remainder ment 68 Embodi- / / 13.65 17.15 Dy 1.5 0.4 0.3 0.30 2.5 0.3 / / / / 1.01 remainder ment 69 Embodi- / / 12.65 18.15 Dy 2.0 0.4 0.3 0.30 2.5 0.3 / / / / 0.96 remainder ment 70 Embodi- / / 11.65 19.15 Dy 2.5 0.4 0.35 0.30 2.5 0.3 / / / / 0.96 remainder ment 71 Embodi- / / 11.65 19.15 Dy 2.5 0.4 0.45 0.30 2.5 0.3 / / / / 0.96 remainder ment 72 Embodi- / / 13.65 17.15 Tb 2 0.4 0.3 0.30 2.5 0.3 / / / / 0.96 remainder ment 73 Embodi- / / 12.65 18.15 Tb 1.2 0.4 0.3 0.30 2.5 0.3 / / / / 0.96 remainder ment 74 Embodi- Ce 0.3 11.35 18.15 Tb 1.2 0.4 0.6 0.4 2.5 0.3 / / / / 0.96 remailider ment 75 Compar- / / 22 8.00 / / / / / / / / / / / 0.96 remainder ative Embodi- ment 1 Compar- / / 22 8.00 / / 0.4 0 0.4 2.5 0.3 / / Cr 0.12 0.96 remainder ative Embodi- ment 2

EMBODIMENT

[0145] The preparation method for the RTB-based permanent magnet material is as follows:

[0146] (1) Melting process: according to the formula shown in Table 1, the pre-made raw materials were put into the crucible made of aluminum oxide, and vas 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.

[0147] (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.

[0148] (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 fill hydrogen absorption, the temperature was raised while vacuuming for Mil dehydrogenation; then cooled, and took out the powder obtained from hydrogen decrepitation.

[0149] (4) Micro-pulverization process: In nitrogen atmosphere 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 content of oxygen (ppm) in nitrogen atmosphere is shown in Table 2.

[0150] (5) The zinc stearate was added to the powder obtained from jet mill pulverization, and mixed fully by v-type mixer. The added amount of zinc stearate is shown in Table 2, and the percentage refers to the weight percentage in the mixed powder.

[0151] (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 0.35ton/cm.sup.2; demagnetization was carried out in a magnetic field of 0.2 T after forming. The content of O (oxygen) in the atmosphere during the pressing process was shown in Table 2 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.

[0152] (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, it was 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.

[0153] (8) Aging treatment process: The sintered body was heated from 20° C. to 630° C. at a heating rate of 3-5° C./min in the Ar of high purity; after 3 hours of heat treatment at 630° C., it was cooled to room temperature and taken out.

Embodiments 2-75, Comparative Embodiments 1-2

[0154] The formulas of Embodiments 2-75, comparative embodiments 1-2 are shown in Table 1, the preparation process is shown in Table 2, and the remaining steps are the same as those in Embodiment 1.

Embodiment 76

[0155] The sintered body obtained in Embodiment 1 was first subjected to grain boundary diffusion treatment and then to aging treatment. The preparation process is shown in Table 2, and the other steps are the same as those in Embodiment 1. The process of grain boundary diffusion treatment is as follows:

[0156] The sintered body was processed into the magnet with diameter of 20 mm, and the thickness of the sheet material was less than 7 mm, the direction of the thickness was the direction of magnetic field orientation, after the surface was cleaned, the raw material prepared with Dy 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.

Embodiment 77

[0157] The sintered body obtained in Embodiment 1 was first subjected to grain boundary diffusion treatment and then to aging treatment. The preparation process is shown in Table 2, and the other steps are the same as those in Embodiment 1. The process of rain boundary diffusion treatment is as follows:

[0158] The sintered body was processed into the magnet with diameter of 20 mm, and the thickness of the sheet material was less than 7 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 Tb 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.

TABLE-US-00002 TABLE 2 Content of O Amount of Content of O Grain Elements in (ppm) in the zinc stearate (ppm) in the boundary grain milling process (%) added in pressing process diffusion boundary No. of step 4 Step 5 of step 6 (Y/N) diffusion Embodiment 1 0 0.04 10 N / Embodiment 2 5 0.05 12 N / Embodiment 3 10 0.06 14 N / Embodiment 4 15 0.07 16 N / Embodiment 5 20 0.08 18 N / Embodiment 6 25 0.09 20 N / Embodiment 7 30 0.10 22 N / Embodiment 8 35 0.11 24 N / Embodiment 9 40 0.12 26 N / Embodiment 10 45 0.13 28 N / Embodiment 11 50 0.14 30 N / Embodiment 12 0 0.04 10 N / Embodiment 13 5 0.05 12 N / Embodiment 14 10 0.06 14 N / Embodiment 15 15 0.07 16 N / Embodiment 16 20 0.08 18 N / Embodiment 17 25 0.09 20 N / Embodiment 18 30 0.10 22 N / Embodiment 19 35 0.11 24 N / Embodiment 20 40 0.12 26 N / Embodiment 21 45 0.13 28 N / Embodiment 22 50 0.14 30 N / Embodiment 23 15 0.07 16 N / Embodiment 24 20 0.08 18 N / Embodiment 25 15 0.07 16 N / Embodiment 26 20 0.08 18 N / Embodiment 27 0 0.04 10 N / Embodiment 28 5 0.05 12 N / Embodiment 29 10 0.06 14 N / Embodiment 30 15 0.07 16 N / Embodiment 31 20 0.08 18 N / Embodiment 32 25 0.09 20 N / Embodiment 33 30 0.10 22 N / Embodiment 34 35 0.11 24 N / Embodiment 35 40 0.12 26 N / Embodiment 36 0 0.04 10 N / Embodiment 37 5 0.05 12 N / Embodiment 38 10 0.06 14 N / Embodiment 39 15 0.07 16 N / Embodiment 40 20 0.08 18 N / Embodiment 41 25 0.09 20 N / Embodiment 42 30 0.10 22 N / Embodiment 43 35 0.11 24 N / Embodiment 44 40 0.12 26 N / Embodiment 45 45 0.13 28 N / Embodiment 46 50 0.14 30 N / Embodiment 47 15 0.07 16 N / Embodiment 48 20 0.08 18 N / Embodiment 49 15 0.07 16 N / Embodiment 50 20 0.08 18 N / Embodiment 51 15 0.07 16 N / Embodiment 52 20 0.08 18 N / Embodiment 53 15 0.07 16 N / Embodiment 54 20 0.08 18 N / Embodiment 55 0 0.04 10 N / Embodiment 56 5 0.05 12 N / Embodiment 57 10 0.06 14 N / Embodiment 58 15 0.07 16 N / Embodiment 59 20 0.08 18 Embodiment 60 25 0.09 20 Embodiment 61 30 0.10 22 N / Embodiment 62 35 0.11 24 N / Embodiment 63 40 0.12 26 N / Embodiment 64 45 0.13 28 N / Embodiment 65 50 0.14 30 N / Embodiment 66 15 0.07 16 N / Embodiment 67 0 0.04 10 N / Embodiment 68 5 0.05 12 N / Embodiment 69 10 0.06 14 N / Embodiment 70 15 0.07 16 N / Embodiment 71 20 0.08 18 N / Embodiment 72 25 0.09 20 N / Embodiment 73 30 0.10 22 N / Embodiment 74 35 0.11 24 N / Embodiment 75 40 0.12 26 N / Embodiment 76 0 0.04 10 Y Dy Embodiment 77 0 0.04 10 Y Tb Comparative 20 0.08 18 N / Embodiment 1 Comparative 20 0.08 18 N / Embodiment 2 Note: The percentage of zinc stearate added refers to the weight percentage in the mixed powder, and the content of O (oxygen) refers to the content of O (oxygen) atom in the atmosphere.

Effect Embodiment

[0159] The magnetic properties and composition of RTB-based permanent magnet materials prepared in Embodiments 1-77 and Comparative embodiments 1-2 were determined, and the crystal phase structure of the magnets was observed by Fe-EPMA.

[0160] (1) Evaluation of magnetic properties: The NIM-10000H BR 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 test results of magnetic properties are shown in Table 3 below,

TABLE-US-00003 TABLE 3 Absolute value Absolute value Absolute value of Hcj of Hcj of Hcj temperature temperature temperature coefficient at coefficient at coefficient at No. Br(kGs) Hcj(kOe) 80° C. 150° C. 180° C. Embodiment 1 14.5 16.37 0.748 / / Embodiment 2 14.51 16.9 0.735 / / Embodiment 3 14.48 17.23 0.701 / / Embodiment 4 14.42 17.75 0.662 / / Embodiment 5 14.37 18.26 0.647 / / Embodiment 6 14.35 18.51 0.653 / / Embodiment 7 14.30 19.03 0.648 / / Embodiment 8 14.25 19.54 0.642 / / Embodiment 9 14.2 20.05 0.637 / / Embodiment 10 14.15 20.56 0.631 / / Embodiment 11 14.11 21.08 0.626 / / Embodiment 12 14.34 17.06 0.715 / / Embodiment 13 14.16 18.14 0.652 / / Embodiment 14 14.03 19.54 0.641 / / Embodiment 15 13.91 20.55 0.632 / / Embodiment 16 13.82 21.32 0.622 / / Embodiment 17 14.32 16.68 0.731 / / Embodiment 18 14.27 17.12 0.715 / / Embodiment 19 14.17 17.92 0.668 / / Embodiment 20 14.02 18.93 0.648 / / Embodiment 21 13.88 19.94 0.639 / / Embodiment 22 13.76 20.7 0.637 / / Embodiment 23 13.62 21.71 0.618 / / Embodiment 24 13.5 22.46 0.605 / / Embodiment 25 13.36 23.47 0.597 / / Embodiment 26 13.22 24.48 / / / Embodiment 27 14.68 16.58 0.734 0.524 / Embodiment 28 14.65 17.51 0.668 / / Embodiment 29 14.61 18.11 0.653 / / Embodiment 30 14.55 18.70 0.651 / / Embodiment 31 14.43 19.59 0.641 / / Embodiment 32 14.38 20.39 0.636 / / Embodiment 33 14.3 22.85 0.601 0.526 / Embodiment 34 13.95 24.39 / 0.522 / Embodiment 35 13.93 24.42 / / / Embodiment 36 14.02 18.43 0.668 / / Embodiment 37 14.39 18.69 0.654 / / Embodiment 38 13.72 19.45 0.648 / / Embodiment 39 13.85 18.61 0.657 / / Embodiment 40 13.81 18.81 0.653 / / Embodiment 41 13.76 19.19 0.649 / / Embodiment 42 13.89 18.59 0.656 / / Embodiment 43 13.86 18.75 0.652 / / Embodiment 44 13.80 19.08 0.651 / / Embodiment 45 14.09 17.22 0.713 / / Embodiment 46 14.05 17.76 0.710 / / Embodiment 47 13.94 18.65 0.654 / / Embodiment 48 13.81 19.71 0.639 / / Embodiment 49 13.58 20.86 0.637 / / Embodiment 50 13.54 21.23 0.621 / / Embodiment 51 13.38 22.34 0.610 / / Embodiment 52 13.25 23.19 0.602 / / Embodiment 53 13.33 23.69 0.594 / / Embodiment 54 13.02 24.49 / 0.523 / Embodiment 55 13.05 24.43 / 0.521 / Embodiment 56 13.49 21.67 0.618 / / Embodiment 57 12.95 25.41 / 0.515 / Embodiment 58 14.17 16.97 0.735 / / Embodiment 59 14.24 17.66 0.713 / / Embodiment 60 13.9 19.13 0.651 / / Embodiment 61 14.12 17.44 0.672 / / Embodiment 62 13.92 18.68 0.652 / / Embodiment 63 13.7 20.15 0.639 / / Embodiment 64 13.56 21.64 0.619 / / Embodiment 65 13.41 23.09 0.605 / / Embodiment 66 13.3 24.76 / 0.519 / Embodiment 67 13.15 24.02 / 0.521 / Embodiment 68 13.12 24.21 / 0.519 / Embodiment 69 12.39 27.81 / 0.491 / Embodiment 70 12.31 29.42 / 0.488 / Embodiment 71 11.95 31.02 / / 0.442 Embodiment 72 12.01 30.51 / / 0.448 Embodiment 73 12.11 31.09 / / 0.442 Embodiment 74 12.39 29.39 / 0.488 / Embodiment 75 12.35 23.03 0.605 / / Embodiment 76 14.32 22.38 0.610 / / Embodiment 77 14.35 28.15 / 0.503 / Comparative 13.8 14.9 0.803 / / Embodiment 1 Comparative 14.1 14.2 0.819 / / Embodiment 2

[0161] (2) Composition determination: The components were determined by high frequency inductively coupled plasma emission spectrometer (TCP-OES). The composition test results are shown in Table 4 below.

TABLE-US-00004 TABLE 4 R R Nd Pr RH RH Cu Al Ga Co Zr Nb Mn M M B Fe C O N No. kind dose wt. % wt. % kind wt. % wt. % wt. % wt. % wt. % wt. % wt. % wt. % kind wt. % wt. % wt. % wt. % wt. % wt. % Embodi- / / 21.648 8.849 / / / / / / / / / / / 0.948 remainder 0.1069 0.039 0.0482 ment 1 Embodi- / / 19.649 10.849 / / / / / / / / / / / 0.947 remainder 0.1251 0.0412 0.0458 ment 2 Embodi- / / 18.335 12.151 / / / / / / / / / / / 0.951 remainder 0.1532 0.0432 0.0439 ment 3 Embodi- / / 16.349 14.152 / / / / / / / / / / / 0.952 remainder 0.1759 0.0468 0.0401 ment 4 Embodi- / / 14.348 16.151 / / / / / / / / / / / 0.951 remainder 0.1835 0.0493 0.0375 ment 5 Embodi- / / 13.348 17.152 / / / / / / / / / / / 0.947 remainder 0.1965 0.0523 0.0342 ment 6 Embodi- / / 11.3481 19.15 / / / / / / / / / / / 0.951 remainder 0.2139 0.0558 0.0302 ment 7 Embodi- / / 9.349 21.148 / / / / / / / / / / / 0.947 remainder 0.2248 0.0635 0.0251 ment 8 Embodi- / / 7.351 23.149 / / / / / / / / / / / 0.947 remainder 0.2248 0.0635 0.0251 ment 9 Embodi- / / 5.352 25.152 / / / / / / / / / / / 0.951 remainder 0.2379 0.0669 0.0223 ment 10 Embodi- / / 3.348 27.148 / / / / / / / / / / / 0.947 remainder 0.2456 0.0685 0.0182 ment 11 Embodi- / / 22.149 8.851 / / 0.201 / / / / / / / / 0.951 remainder 0.1072 0.0382 0.0482 ment 12 Embodi- / / 18.849 12.15 / / 0.302 / / / / / / / / 1.011 remainder 0.1256 0.0442 0.0461 ment 13 Embodi- / / 13.848 17.15 / / 0.351 / / / / / / / / 1.009 remainder 0.1537 0.0456 0.0442 ment 14 Embodi- / / 10.851 20.15 / / 0.451 / / / / / / / / 1.008 remainder 0.1764 0.0492 0.0404 ment 15 Embodi- / / 7.849 23.15 / / 0.50 / / / / / / / / 0.998 remainder 0.1843 0.0501 0.0378 ment 16 Embodi- / / 22.149 8.848 / / / 0.021 / / / / / / / 1.011 remainder 0.1973 0.0529 0.0347 ment 17 Embodi- / / 20.851 10.151 / / / 0.041 / / / / / / / 0.949 remainder 0.2147 0.0564 0.0307 ment 18 Embodi- / / 18.849 12.148 / / / 0.101 / / / / / / / 0.948 remainder 0.2251 0.0588 0.029 ment 19 Embodi- / / 16.848 14.149 / / / 0.202 / / / / / / / 0.948 remainder 0.2248 0.0641 0.0256 ment 20 Embodi- / / 14.849 16.151 / / / 0.301 / / / / / / / 0.949 remainder 0.2379 0.0675 0.0228 ment 21 Embodi- / / 13.852 17.151 / / / 0.401 / / / / / / / 0.949 remainder 0.2456 0.0691 0.0187 ment 22 Embodi- / / 11.851 19.150 / / / 0.497 / / / / / / / 0.948 remainder 0.1761 0.0494 0.0397 ment 23 Embodi- / / 10.851 20.152 / / / 0.602 / / / / / / / 0.951 remainder 0.184  0.0503 0.0371 ment 24 Embodi- / / 8.852 22.151 / / / 0.702 / / / / / / / 0.949 remainder 0.1761 0.0494 0.0397 ment 25 Embodi- / / 6.851 24.152 / / / 0.801 / / / / / / / 0.95 remainder 0.1846 0.05 0.0366 ment 26 Embodi- / / 20.652 8.851 / / / / 0.102 / / / / / / 0.948 remainder 0.1069 0.0384 0.0476 ment 27 Embodi- / / 19.652 9.85 / / / / 0.2 / / / / / / 0.981 remainder 0.1253 0.0444 0.0455 ment 28 Embodi- / / 18.651 10.848 / / / / 0.251 / / / / / / 0.982 remainder 0.1534 0.0458 0.0436 ment 29 Embodi- / / 17.652 11.848 / / / / 0.302 / / / / / / 0.985 remainder 0.1761 0.0494 0.0398 ment 30 Embodi- / / 17.352 12.148 / / / / 0.421 / / / / / / 0.981 remainder 0.184 0.0503 0.0341 ment 31 Embodi- / / 16.350 13.149 / / / / 0.501 / / / / / / 0.982 remainder 0.197  0.0531 0.0341 ment 32 Embodi- / / 15.353 14.148 / / / / 0.901 / / / / / / 0.985 remainder 0.2144 0.0566 0.0301 ment 33 Embodi- / / 9.352 20.148 / / / / 1.402 / / / / / / 0.981 remainder 0.2248 0.059 0.0284 ment 34 Embodi- / / 8.351 21.148 / / / / 1.552 / / / 0.01 / / 0.982 remainder 0.2245 0.0643 0.025 ment 35 Embodi- / / 14.335 17.149 / / / / / 0.501 / / / / / 0.985 remainder 0.1759 0.0468 0.0401 ment 36 Embodi- / / 13.352 18.148 / / / / / 1.021 / / / / / 0.981 remainder 0.1835 0.0493 0.0375 ment 37 Embodi- / / 12.352 19.148 / / / / / 2.501 / / / / / 1.010 remainder 0.1965 0.0523 0.0342 ment 38 Embodi- / / 14.351 17.148 / / / / / / 0.251 / / / / 1.009 remainder 0.2139 0.0558 0.0302 ment 39 Embodi- / / 13.352 18.149 / / / / / / 0.301 / / / / 1.011 remainder 0.2243 0.0582 0.0285 ment 40 Embodi- / / 12.351 19.149 / / / / / / 0.351 / / / / 1.010 remainder 0.1072 0.0382 0.0482 ment 41 Embodi- / / 14.35 17.148 / / / / / / / 0.251 / / / 1.009 remainder 0.2379 0.0669 0.0223 ment 42 Embodi- / / 13.353 18.151 / / / / / / / 0.301 / / / 1.0011 remainder 0.2456 0.0685 0.0182 ment 43 Embodi- / / 12.351 19.148 / / / / / / / 0.351 / / / 1.010 remainder 0.1072 0.0382 0.0482 ment 44 / Embodi- / / 22.652 8.848 / / 0.341 0.021 / / / / / / / 1.009 remainder 0.1256 0.0442 0.0461 ment 45 Embodi- / / 21.353 10.149 / / 0.382 0.041 / / / / / / / 1.010 remainder 0.1537 0.0456 0.0442 ment 46 Embodi- / / 19.351 12.148 / / 0.42 0.103 / / / / / / / 1.009 remainder 0.1764 0.0492 0.0404 ment 47 Embodi- / / 17.352 14.151 / / 0.441 0.202 / / / / / / / 1.011 remainder 0.1843 0.0501 0.0378 ment 48 Embodi- / / 15.352 16.152 / / 0.501 0.302 / / / / / / / 1.010 remainder 0.1973 0.0529 0.0347 ment 49 Embodi- / / 14.352 17.152 / / 0.34 0.403 / / / / / / / 1.010 remainder 0.2147 0.0564 0.307 ment 50 Embodi- / / 12.352 19.148 / / 0.381 0.501 / / / / / / / 1.009 remainder 0.2251 0.0588 0.029 ment 51 Embodi- / / 11.351 20.148 / / 0.42 0.602 / / / / / / / 1.011 remainder 0.2248 0.0641 0.0256 ment 52 Embodi- / / 9.352 22.149 / / 0.341 0.502 0.102 / / / / / / 1.010 remainder 0.2379 0.0675 0.0228 ment 53 Embodi- / / 7.353 24.148 / / 0.401 0.602 0.302 / / / / / / 1.009 remainder 0.2456 0.0691 0.0187 ment 54 Embodi- / / 13.653 17.152 / / 0.501 0.81 0.421 / / / / / / 1.010 remainder 0.1761 0.0494 0.0398 ment 55 Embodi- / / 8.651 22.151 / / 0.341 0.501 0.102 / 0.25 / / / / 1.009 remainder 0.184  0.0503 0.0371 ment 56 Embodi- / / 6.652 24.151 / / 0.501 0.802 0.302 / 0.30 / / / / 1.011 remainder 0.1761 0.0494 0.0397 ment 57 Embodi- / / 21.951 8.846 / / 0.34 0.01 0.251 / / / / / / 1.010 remainder 0.1846 0.05 0.0366 ment 58 Embodi- / / 20.652 10.148 / / 0.381 0.021 0.302 / / / / / / 0.962 remainder 0.1069 0.0384 0.0476 ment 59 Embodi- / / 18.652 12.15 / / 0.421 0.03 0.42 / / / / / / 0.958 remainder 0.1253 0.0444 0.0455 ment 60 Embodi- / / 16.651 14.147 / / 0.382 0.042 0.102 / / / / / / 0.958 remainder 0.1534 0.0458 0.0436 ment 61 Embodi- / / 14.652 16.148 / / 0.4202 0.102 0.151 / / / / / / 0.958 remainder 0.1761 0.0494 0.0398 ment 62 Embodi- / / 13.651 17.149 / / 0.441 0.202 0.251 / / / / / / 0.958 remainder 0.184 0.0503 0.0372 ment 63 Embodi- / / 11.652 19.152 / / 0.502 0.302 0.301 / / / / / / 0.961 remainder 0.197  0.0531 0.0341 ment 64 Embodi- / / 10.651 20.149 / / 0.451 0.402 0.421 / / / / / / 0.985 remainder 0.2144 0.0566 0.0301 ment 65 Embodi- / / 8.052 22.149 / / 0.502 0.502 0.502 / / / / / / 1.009 remainder 0.2248 0.059 0.0284 ment 66 Embodi- / / 12.651 18.151 / / 0.401 0.602 0.401 2.501 0.302 / / Cr 0.05 1.011 remainder 0.2245 0.0643 0.025 ment 67 Embodi- / / 12.652 18.152 / / 0.403 0.601 0.401 2.501 0.302 / / Cr 0.12 1.012 remainder 0.1062 0.039 0.0482 ment 68 Embodi- / / 13.649 17.151 Dy 1.51  0.403 0.302 0.301 2.502 0.301 / / / / 1.011 remainder 0.1251 0.0412 0.0458 ment 69 Embodi- / / 12.649 18.152 Dy 2.011 0.4 0.298 0.301 2.502 0.302 / / / / 0.958 remainder 0.1532 0.0432 0.0439 ment 70 Embodi- / / 11.651 19.152 Dy 2.511 0.41 0.351 0.30 2.501 0.303 / / / / 0.961 remainder 0.1759 0.0468 0.0401 ment 71 Embodi- / / 11.652 19.151 Dy 2.512 0.402 0.451 0.302 2.501 0.303 / / / / 0.962 remainder 0.1835 0.0493 0.0375 ment 72 Embodi- / / 13.651 17.152 Tb 1.991 0.402 0.302 0.301 2.505 0.303 / / / / 0.958 remainder 0.1965 0.0523 0.0342 ment 73 Embodi- / / 12.650 18.151 Tb 1.212 0.402 0.302 0.301 2.501 0.308 / / / / 0.961 remainder 0.2139 0.0558 0.0302 ment 74 Embodi- Ce 0.29 11.352 18.152 Tb 1.219 0.41 0.601 0.399 2.491 0.298 / / / / 0.962 remainder 0.2234 0.0582 0.0085 ment 75 Embodi- / / 21.647 8.848 Dy 0.62  / / / / / / / / / 0.947 remainder 0.1075 0.041 0.0485 ment 76 Embodi- / / 21.649 8.846 Tb 0.58  / / / / / / / / / 0.946 remainder 0.1069 0.0391 0.0486 ment 77 Compara- / / 21.998 7.988 / / / / / / / / / / / 0.958 remainder 0.2248 0.0635 0.0251 tive Embodi- ment 1 Compara- / / 22.094 7.989 / / 0.401 0 0.403 2.489 0.289 / / Cr 0.121 0.961 remainder 0.2379 0.0669 0.0223 tive Embodi- ment 2

[0162] (3) Fe-EPMA detection: The vertical orientation surfaces of the RTB-based magnet materials in Embodiments 1, 2, 11, 12, 21, 23, 34, 35, 39, 43, 51, 52, 60, 63, 68, 69 and Comparative Embodiments 1 and 2 in Table 4 were polished. Field emission electron probe microanalyzer (FE-EPMA) (JEOL, 8530F) was used for detection.

[0163] The position of intergranular triangle region in Embodiment 68 (as shown at position a in FIG. 1) was investigated for composition, and the relative volume ratio of the phase of the triangle region rare-earth-rich phase) to all phases of the observation surface (main phase, the grain boundary phase and the rare-earth-rich phase) was determined, which can be found that in the samples containing high Pr and high C, the ration of the phases formed in intergranular region was relatively low, which was not seen in the samples containing low Pr. The specific test results are shown in Table 5 below.

TABLE-US-00005 TABLE 5 Proportion of phases in the Intergranular triangle region Intergranular- R′ Ga + Cu O triangle region No. (mass ratio) (mass ratio) (mass ratio) / Embodiment 1 85.4 / 14.6 4.6 Embodiment 2 85.3 / 14.7 5.3 Embodiment 11 85.3 / 14.7 4.8 Embodiment 12 85.4 0.9 (Cu) 13.7 3.2 Embodiment 21 85.3 / 14.7 3.3 Embodiment 23 85.3 / 14.7 4.6 Embodiment 34 85.2 0.4 (Ga) 14.4 4.8 Embodiment 35 85 0.6 (Ga) 14.4 3.7 Embodiment 39 85.2 / 14.8 3.2 Embodiment 43 85.3 / 14.7 3.3 Embodiment 51 84.9 0.8 (Cu) 14.3 4.6 Embodiment 52 84.9 0.6 (Cu) 14.5 4.8 Embodiment 60 84.35 0.3 (Cu) + 0.6 (Ga) 14.75 3.2 Embodiment 63 84.8 0.4 (Cu) + 0.4 (Ga) 14.4 3.3 Embodiment 68 85.85 0.4 (Cu) + 0.5 (Ga) 13.25 4.6 Embodiment 69 84.8 0.4 (Cu) + 0.6 (Ga) 14.2 4.8 Comparative 85.3 / 14.7 9.8 Embodiment 1 Comparative 84.7 0.4 (Cu) + 0.6 (Ga) 14.3 12.5 Embodiment 2 Note: The mass ratio of R′, Ga, Cu and O in the intergranular triangle region refers to the mass percentage in the total mass of elements in the intergranular triangle region; the volume ratio of the phase in intergranular triangle region refers to the percentage of the volume of the phase in intergranular triangle region with respect to the sum of the volume of the &lddquo;main phase, the grain boundary phase and the intergranular triangle region”.