Ferrite sintered magnet

Patent metadata

Field	Value
Publication number	US-10373746-B2
Application number	US-201715400459-A
Country	US
Kind code	B2
Filing date	Jan 6, 2017
Priority date	Jan 15, 2016
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

A ferrite sintered magnet includes a composition expressed by a formula (1) of Ca 1-w-x La w A x Fe z Co m O 19 . In the formula (1), “w”, “x”, “z”, and “m” satisfy a formula (2) of 0.30≤w≤0.50, a formula (3) of 0.08≤x≤0.20, a formula (4) of 8.55≤z≤10.00, and a formula (5) of 0.20≤m≤0.40. In the formula (1), “A” is at least one kind of element selected from a group consisting of Sr and Ba. Cr is further contained at 0.058 mass % to 0.132 mass % in terms of Cr 2 O 3 .

First claim

The invention claimed is:

1. A ferrite sintered magnet comprising a composition expressed by a following formula (1),
Ca 1-w-x La w A x Fe z Co m O 19   (1)

wherein “w”, “x”, “z”, and “m” in the formula (1) satisfy following formulae (2), (3), (4), and (5),
0.30≤ w≤ 0.50  (2)

0.08≤ x≤ 0.20  (3)

8.55≤ z≤ 10.00  (4)

0.20≤ m≤ 0.40  (5)

“A” in the formula (1) is at least one kind of element selected from a group consisting of Sr and Ba,
Cr is further contained at 0.058 mass % to 0.132 mass % in terms of Cr 2 O 3 , and
S is further contained at more than 0 ppm to less than 100 ppm.

2. The ferrite sintered magnet according to claim 1 , wherein
a relationship between x1 and y1 is in a range surrounded by six points of a1 (0.058, 10.25), b1 (0.119, 10.25), c1 (0.132, 9.30), d1 (0.119, 9.30), e1 (0.100, 8.75), and f1 (0.058, 8.75) in X-Y coordinates having an X-axis and a Y-axis,
where x1 is an amount (mass %) of Cr 2 O 3 in the ferrite sintered magnet and is expressed on the X-axis and
y1 is a total amount of “z” and “m” in the ferrite sintered magnet and is expressed on the Y-axis.

3. The ferrite sintered magnet according to claim 1 , wherein w/m is 0.98 to 2.00.

4. The ferrite sintered magnet according to claim 2 , wherein w/m is 0.98 to 2.00.

5. The ferrite sintered magnet according to claim 1 , wherein Si is further contained at 0.55 mass % to 1.12 mass % in terms of SiO 2 .

6. The ferrite sintered magnet according to claim 2 , wherein Si is further contained at 0.55 mass % to 1.12 mass % in terms of SiO 2 .

7. The ferrite sintered magnet according to claim 3 , wherein Si is further contained at 0.55 mass % to 1.12 mass % in terms of SiO 2 .

8. The ferrite sintered magnet according to claim 4 , wherein Si is further contained at 0.55 mass % to 1.12 mass % in terms of SiO 2 .

9. The ferrite sintered magnet according to claim 1 , wherein Al is contained at 0.01 mass % to 0.97 mass % in terms of Al 2 O 3 .

10. The ferrite sintered magnet according to claim 2 , wherein Al is contained at 0.01 mass % to 0.97 mass % in terms of Al 2 O 3 .

11. The ferrite sintered magnet according to claim 3 , wherein Al is contained at 0.01 mass % to 0.97 mass % in terms of Al 2 O 3 .

12. The ferrite sintered magnet according to claim 4 , wherein Al is contained at 0.01 mass % to 0.97 mass % in terms of Al 2 O 3 .

13. A ferrite sintered magnet comprising a composition expressed by a following formula (1),
Ca 1-w-x La w A x Fe z Co m O 19   (1)

wherein “w”, “x”, “z”, and “m” in the formula (1) satisfy following formulae (2), (3), (4), and (5),
0.30≤ w≤ 0.50  (2)

0.08≤ x≤ 0.20  (3)

8.55≤ z≤ 10.00  (4)

0.20≤ m≤ 0.40  (5)

“A” in the formula (1) is at least one kind of element selected from a group consisting of Sr and Ba,
Cr is further contained at 0.058 mass % to 0.132 mass % in terms of Cr 2 O 3 , and
Al is contained at 0.01 mass % to 0.97 mass % in terms of Al 2 O 3 .

14. The ferrite sintered magnet according to claim 13 , wherein
a relationship between x1 and y1 is in a range surrounded by six points of a1 (0.058, 10.25), b1 (0.119, 10.25), c1 (0.132, 9.30), d1 (0.119, 9.30), e1 (0.100, 8.75), and f1 (0.058, 8.75) in X-Y coordinates having an X-axis and a Y-axis,
where x1 is an amount (mass %) of Cr 2 O 3 in the ferrite sintered magnet and is expressed on the X-axis and
y1 is a total amount of “z” and “m” in the ferrite sintered magnet and is expressed on the Y-axis.

15. The ferrite sintered magnet according to claim 13 , wherein w/m is 0.98 to 2.00.

16. The ferrite sintered magnet according to claim 14 , wherein w/m is 0.98 to 2.00.

17. The ferrite sintered magnet according to claim 13 , wherein Si is further contained at 0.55 mass % to 1.12 mass % in terms of SiO 2 .

18. The ferrite sintered magnet according to claim 14 , wherein Si is further contained at 0.55 mass % to 1.12 mass % in terms of SiO 2 .

19. The ferrite sintered magnet according to claim 15 , wherein Si is further contained at 0.55 mass % to 1.12 mass % in terms of SiO 2 .

20. The ferrite sintered magnet according to claim 16 , wherein Si is further contained at 0.55 mass % to 1.12 mass % in terms of SiO 2 .

Assignees

• Tdk Corp

Inventors

• Morita Hiroyuki

Classifications

• C04B2235/96

  Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance · CPC title

• C04B2235/3454

  Calcium silicates, e.g. wollastonite · CPC title

• C04B2235/5409

  expressed by specific surface values · CPC title

• C04B35/2633 Primary

  containing barium, strontium or calcium · CPC title

• C04B2235/549

  the particle size being expressed by crystallite size or primary particle size · CPC title