Ferrite sintered magnet and rotating electric machine comprising the same

Patent metadata

Field	Value
Publication number	US-11610705-B2
Application number	US-202016823871-A
Country	US
Kind code	B2
Filing date	Mar 19, 2020
Priority date	Mar 27, 2019
Publication date	Mar 21, 2023
Grant date	Mar 21, 2023

Abstract

A ferrite sintered magnet comprising an M type Sr ferrite having a hexagonal structure as a main phase, wherein the ferrite sintered magnet does not substantially comprise a rare earth element and Co, a content of B is 0.005 to 0.9% by mass in terms of B 2 O 3 , and a content of Zn is 0.01 to 1.2% by mass in terms of ZnO.

First claim

What is claimed is:

1. A ferrite sintered magnet comprising an M type Sr ferrite having a hexagonal structure as a main phase, wherein
the ferrite sintered magnet does not substantially comprise a rare earth element and Co,
a content of B is 0.005 to 0.9% by mass in terms of B 2 O 3 , and
a content of Zn is 0.01 to 1.2% by mass in terms of ZnO.

2. The ferrite sintered magnet according to claim 1 , wherein a content of Si is 0.05 to 1.3% by mass in terms of SiO 2 .

3. The ferrite sintered magnet according to claim 1 , wherein a content of Ca is 0.15 to 2.0% by mass in terms of CaO.

4. The ferrite sintered magnet according to claim 1 , wherein the ferrite sintered magnet satisfies 11.3≤[Fe]/[Sr]≤13.1 when an atomic concentration of Fe is represented by [Fe] and an atomic concentration of Sr is represented by [Sr].

5. The ferrite sintered magnet according to claim 1 , wherein the ferrite sintered magnet satisfies 0.92≤[B+Ca+Zn]/[Si]≤11.45 when a total atomic concentration of B, Ca, and Zn is represented by [B+Ca+Zn] and an atomic concentration of Si is represented by [Si].

6. The ferrite sintered magnet according to claim 1 , wherein the ferrite sintered magnet satisfies 0.1≤Z≤3.25 when a total atomic concentration of Ca, Sr, and Ba is represented by [Ca+Sr+Ba], a total atomic concentration of Fe, Mn, Zn, Cr, and Al is represented by [Fe+Mn+Zn+Cr+Al], a total atomic concentration of Si and B is represented by [Si+B], and Z=([Ca+Sr+Ba]−[Fe+Mn+Zn+Cr+Al]/12)/[Si+B].

7. The ferrite sintered magnet according to claim 1 , comprising 0.25 to 1.5% by mass of Mn in terms of MnO.

8. The ferrite sintered magnet according to claim 1 , comprising 0.03 to 0.2% by mass of Cr in terms of Cr 2 O 3 .

9. A rotating electric machine comprising the ferrite sintered magnet according to claim 1 .

Assignees

• Tdk Corp

Inventors

• Murakawa Yoshitaka
• Muroya Shogo
• Morita Hiroyuki
• Ikeda Masanori

Classifications

• C04B2235/3215

  Barium oxides or oxide-forming salts thereof · CPC title

• H01F1/10

  non-metallic substances, e.g. ferrites {, e.g. [(Ba,Sr)O(Fe2O3)6] ferrites with hexagonal structure} · CPC title

• C04B2235/96

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

• C04B2235/3418

  Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint · CPC title

• C01G49/0072

  containing manganese · CPC title