Soft magnetic powder, powder magnetic core, magnetic element, and electronic device

Patent metadata

Field	Value
Publication number	US-11545285-B2
Application number	US-202016858872-A
Country	US
Kind code	B2
Filing date	Apr 27, 2020
Priority date	Dec 16, 2015
Publication date	Jan 3, 2023
Grant date	Jan 3, 2023

Abstract

A soft magnetic powder of the invention has a composition represented by Fe 100-a-b-c-d-e-f Cu a Si b B c M d M′ e X f (at %) [wherein M is Nb, W, Ta, Zr, Hf, Ti, or Mo, M′ is V, Cr, Mn, Al, a platinum group element, Sc, Y, Au, Zn, Sn, or Re, X is C, P, Ge, Ga, Sb, In, Be, or As, and a, b, c, d, e, and f are numbers that satisfy the following formulae: 0.1≤a≤3, 0<b≤30, 0<c≤25, 5≤b+c≤30, 0.1≤d≤30, 0≤e≤10, and 0≤f≤10], wherein a crystalline structure having a particle diameter of 1 nm or more and 30 nm or less is contained in an amount of 40 vol % or more, and the difference in the coercive force of the powder after classification satisfies predetermined conditions.

First claim

What is claimed is:

1. A soft magnetic powder comprising:
first particles having a first particle size that passes through a JIS standard sieve with a sieve opening of 45 μm but does not pass through a JIS standard sieve with a sieve opening of 38 μm,
second particles having a second particle size that pass through the JIS standard sieve with a sieve opening of 38 μm but does not pass through a JIS standard sieve with a sieve opening of 25 μm, and
third particles having a third particle size that pass through the JIS standard sieve with a sieve opening of 25 μm,
wherein an average particle size D50 of the first, second, and third particles is in the range of 1 μm to 40 μm,
wherein each of the first, second, and third particles have a composition comprised of:
Fe100-a-b-c-d-e-fCuaSibBcMdM′eXf

wherein M is at least one element selected from a group consisting of Nb, W, Ta, Zr, Hf, Ti, and Mo,
M′ is at least one element selected from a group consisting of V, Cr, Mn, Al, a platinum group element, Sc, Y, Au, Zn, Sn, and Re,
X is at least one element selected from a group consisting of Sb, In, Be, and As, and
a, b, c, d, e, and f are numbers that represent an atomic percentage (at %) of each element in the composition and satisfy the following formulae: 0.1≤a≤3, 0<b≤30, 0<c≤25, 5≤b+c≤30, 0.1≤d≤30, 0≤e≤10, and 0≤f≤10,
each of the first, second, and third particles have a crystalline structure, the crystalline structure having a diameter of 1 nm or more and 30 nm or less and is contained in an amount of 40 vol % or more, and
the coercive force Hc1 of the first particles, the coercive force Hc2 of the second particles, and the coercive force Hc3 of the third particles satisfy the relationship that Hc2/Hc1 is 0.85 or more and 1.4 or less, and Hc3/Hc1 is 0.5 or more and 1.5 or less.

2. The soft magnetic powder according to claim 1 , wherein when a plot area in which the horizontal axis represents the particle diameter and the vertical axis represents the coercive force is set, and the data of the first particles, the data of the second particles, and the data of the third particles are plotted in the plot area, respectively, and also the data are linearly approximated by the least squares method, and the slope of the obtained straight line is represented by A, A satisfies the following formula: −0.02≤A≤0.05.

3. The soft magnetic powder according to claim 1 , wherein the volume resistivity of a green compact in a compacted state is 1 kΩ·cm or more and 500 kΩ·cm or less.

4. The soft magnetic powder according to claim 1 , wherein the powder further contains an amorphous structure.

5. The soft magnetic powder according to claim 1 , wherein the diameter of the crystalline structure of each of the first, second, and third particles is 10.1 nm or more and 18.5 nm or less, and is contained in an amount of 70 vol % or more.

6. The soft magnetic powder according to claim 1 , wherein each of the first, second, and third particles have a Vickers hardness that is 1220 or more and 1420 or less.

7. The soft magnetic powder according to claim 1 , wherein a coercive force of the soft magnetic powder including the first, second, and third particles is 0.1 Oe or more and 0.5 Oe or less.

8. A powder magnetic core comprising the soft magnetic powder according to claim 2 .

9. A powder magnetic core comprising the soft magnetic powder according to claim 3 .

10. A powder magnetic core comprising the soft magnetic powder according to claim 4 .

11. A powder magnetic core comprising the soft magnetic powder according to claim 5 .

12. A powder magnetic core comprising the soft magnetic powder according to claim 6 .

13. A powder magnetic core comprising the soft magnetic powder according to claim 7 .

Assignees

• Seiko Epson Corp

Inventors

• Kudo Yasuko
• Akazawa Toshiki
• Maeda Yu

Classifications

• C22C38/28

  with titanium or zirconium · CPC title

• B22F2009/088

  Fluid nozzles, e.g. angle, distance · CPC title

• B22F1/10

  Metallic powder containing lubricating or binding agents; Metallic powder containing organic material · CPC title

• C22C38/26

  with niobium or tantalum · CPC title

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title