Rare earth permanent magnetic material and method of preparing the same

Patent metadata

Field	Value
Publication number	US-2016307676-A1
Application number	US-201615192246-A
Country	US
Kind code	A1
Filing date	Jun 24, 2016
Priority date	Dec 27, 2013
Publication date	Oct 20, 2016
Grant date	—

Abstract

A rare earth permanent magnetic material contains a main phase of R1 x1 R2 y1 Fe 1-x1-y1-z1-u1 Co z1 B u1 , and an auxiliary phase including a first auxiliary phase of R3 x2 R4 y2 Fe 1-x2-y2-z2-u2-v1 Co z2 B u2 M v1 and a second auxiliary of R5 x3 R6 y3 Fe 1-x3-y3-z3-u3-v2 Co z3 B u3 M v2 . Each of R1, R3 and R5 is Pr and/or Nd. Each of R2, R4 and R6 is at least one of Dy, Tb and Ho. M is at least one of Zr, Ga, Cu, Nb, Sn, Mo, Al, V, W, Si, Hf, Ti, Zn, Bi, Ta and In. 26 wt %≦x1+y1≦34 wt %, 0.01 wt %≦y1≦4 wt %, 0≦z1≦6 wt %, and 0.78 wt %≦u1≦1.25 wt %. 35 wt %≦x2+y2≦82 wt %, 5 wt %≦y2≦42 wt %, 0≦z2≦40 wt %, 0≦u2≦1.25 wt %, and 0≦v1≦10 wt %. 10 wt %≦x3+y3≦32 wt %, 0≦y3≦4.8 wt %, 0≦z3≦40 wt %, 0≦u3≦1.25 wt %, and 31 wt %≦v2≦50 wt %.

First claim

1 . A rare earth permanent magnetic material comprising:
a main phase represented by R1 x1 R2 y1 Fe 1-x1-y1-z1-u1 Co z1 B u1 , wherein R1 is at least one element selected from Pr and Nd; R2 is at least one element selected from Dy, Tb and Ho; x1, y1, z1 and u1 are weight percentages, 26%≦x1+y1≦34%, 0.01%≦y1≦4%, 0≦z1≦6%, and 0.78%≦u1≦1.25%; and an auxiliary phase separated from or cladding the main phase, comprising a first auxiliary phase and a second auxiliary, wherein the first auxiliary phase is represented by R3 x2 R4 y2 Fe 1-x2-y2-z2-u2-v1 Co z2 B u2 M v1 , where R3 is at least one element selected from Pr and Nd; R4 is at least one element selected from tho group consisting of Dy, Tb and Ho; M is at least one element selected from Zr, Ga, Cu, Nb, Sn, Mo, Al, V, W, Si, Hf, Ti, Zn, Bi, Ta and In; x2, y2, z2, u2 and v1 are weight percents, 35%≦x2+y2≦82%, 5%≦y2≦42%, 0≦z2≦40%, 0≦u2≦1.25%, and 0≦v1≦10%; and the second auxiliary phase is represented by R5 x3 R6 y3 Fe 1-x3-y3-z3-u3-v2 Co z3 B u3 M v2 where R5 is at least one element selected from Pr and Nd; R6 is at least one element selected from Dy, Tb and Ho; M is at least one element selected from Zr, Ga, Cu, Nb, Sn, Mo, Al, V, W, Si, Hf, Ti, Zn, Bi, Ta and In; x3, y3, z3, u3 and v2 are weight percentages, 10%≦x3+v3≦32%. 0≦y3≦4.8%, 0≦z3≦40%, 0≦u3≦1.25%, and 31%≦v2<50%.

2 . The rare earth permanent magnetic material of claim 1 , wherein based on the total weight of the main phase and the auxiliary phase, the content of the first auxiliary C1 satisfies: 0<C1≦25 wt %.

3 . The rare earth permanent magnetic material of claim 2 , wherein based on the total weight of the main phase and the auxiliary phase, the content of the first auxiliary C1 satisfies: 0<C1≦15 wt %.

4 . The rare earth permanent magnetic material of claim 1 , wherein based on the total weight of the main phase and the auxiliary phase, the content of the second auxiliary C2 satisfies: 0<C2≦20 wt %.

5 . The rare earth permanent magnetic material of claim 4 , wherein based on the total weight of the main phase and the auxiliary phase, the content of the second auxiliary C2 satisfies: 0<C2≦10 wt %.

6 . The rare earth permanent magnetic material of claim 1 , wherein 27%≦x1+y1≦33%, 1%≦y1≦4%, 1%≦z1≦3%, and 0.8%≦u1≦1.1%.

7 . The rare earth permanent magnetic material of claim 1 , wherein 37%≦x2+y2≦68%, 9%≦y2≦26%, 0≦z2≦18%, 0≦u2≦1.1%, and 0≦v1≦8%.

8 . The rare earth permanent magnetic material of claim 1 , wherein 10%≦x3+y3≦30%, 0≦y3≦4%, 5%≦z3≦18%, 0≦u3≦1.1%, and 31%≦v2≦48%.

9 . A method of preparing a rare earth permanent magnetic material, comprising:
smelting metals contained in the main phase and molding the melt metals into an ingot or molding the melt metals into an alloy sheet via a quick-setting process to obtain a first alloy of the main phase; smelting metals contained in the first auxiliary phase and molding the melt metals into an ingot or molding the melt metals into an alloy sheet via a quick-setting process to obtain a second alloy of the first auxiliary phase; smelting metals contained in the second auxiliary phase and molding the melt metals into an ingot or molding the melt metals into an alloy sheet via a quick-setting process to obtain a third alloy of the second auxiliary phase; and powdering, mixing, forming, and sintering the first, second and third alloys.

10 . The method of claim 9 , wherein the forming is performed in a magnetic orientation field.

11 . The method of claim 9 , wherein the sintering is performed under vacuum or in the presence of an inert gas.

12 . The method of claim 9 , further comprising crushing the first, second and third alloys before the powdering step.

13 . The method of claim 12 , wherein the crushing is performed by hydrogen decrepitation comprising a hydrogen absorption under a hydrogen pressure of about 0.06 MPa to about 1.5 MPa for about 0.1 hour to 3 hours, and a dehydrogenation at about 400° C. to about 650° C. for about 3 hours to 10 hours.

14 . The method of claim 13 , wherein the powdering comprises jet milling the first, second, and third alloys into powders having an average particle diameter ranging from 1.4 μm to 4.5 μm, and the powders from the first alloy have an average particle diameter ranging from 2.5 μm to 4.5 μm.

15 . The method of claim 14 , further comprising adding an antioxidant into the first, second and third alloys before jet milling, and based on the total weight of a product obtained from the crushing step, the amount of the antioxidant is about 0.02 wt % to 0.17 wt %.

16 . The method of claim 15 , further comprising adding a lubricant into the powders of the first, second and third alloys before the mixing step, and based on the total weight of the powders of the first, second and third alloys, the amount of the lubricant is about 0.02 wt % to about 17 wt %.

17 . The method of claim 10 , wherein the magnetic orientation field comprises a constant magnetic field of about 1.5 Tesla to 3.5 Tesla or a pulsed magnetic field of about 1.5 Tesla to 3.5 Tesla.

18 . The method of claim 17 , wherein the forming further comprises maintaining a formed product under an isostatic pressure of about 160 MPa to about 220 MPa for about 45 seconds to about 120 seconds.

19 . The method of claim 9 , wherein the sintering is performed at about 1040° C. to about 1100° C. for about 3 hours to about 6 hours.

20 . The method of claim 9 , further comprising a tempering step after the sintering step, wherein the tempering comprises a primary tempering performed at about 870° C. to about 950° C. for about 2 hours to about 5 hours, and a secondary tempering performed at about 480° C. to about 560° C. for about 3 hours to about 8 hours.

Assignees

• Byd Co Ltd

Inventors

• Deng Xiaoxia
• Chen Bo
• ZHANG Failang

Classifications

• H01F1/0577 Primary

  sintered · CPC title

• C22C38/002

  containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60 · CPC title

• C22C38/14

  containing titanium or zirconium · CPC title

• B22F3/24

  After-treatment of workpieces or articles {(B22F3/1146 takes precedence)} · CPC title

• C22C30/04

  containing tin or lead · CPC title