Soft-magnetic, amorphous alloy ribbon and its production method, and magnetic core constituted thereby

Patent metadata

Field	Value
Publication number	US-9290831-B2
Application number	US-201013392427-A
Country	US
Kind code	B2
Filing date	Sep 14, 2010
Priority date	Sep 14, 2009
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A soft-magnetic, amorphous alloy ribbon produced by a rapid quenching method, having transverse lines of recesses formed on its surface by laser beams with predetermined longitudinal intervals, with a doughnut-shaped projection formed around each recess; doughnut-shaped projections having smooth surfaces substantially free from splashes of the alloy melted by the irradiation of laser beams, and a height t 2 of 2 μm or less; and a ratio t 1 /T of the depth t 1 of the recesses to the thickness T of the ribbon being in a range of 0.025-0.18, thereby having low iron loss and low apparent power.

First claim

What is claimed is:

1. A soft-magnetic, amorphous alloy ribbon produced by a rapid quenching method, having transverse lines of recesses formed on its surface by laser beams with predetermined longitudinal intervals, with a doughnut-shaped projection formed around each recess; said recesses and said doughnut-shaped projections being constituted by an amorphous phase; said doughnut-shaped projections having smooth surfaces substantially free from splashes of the alloy melted by the irradiation of laser beams, and a height t 2 of 2 μm or less; and a ratio t 1 /T of the depth t 1 of said recesses to the thickness T of said ribbon being in a range of 0.025-0.18, wherein the number density of said recesses in the transverse lines is 2-20/mm, and wherein a surface of said ribbon to be irradiated with laser beams has reflectance of 15-80% at a wavelength λ of 1000 nm.

2. The soft-magnetic, amorphous alloy ribbon according to claim 1 , wherein the openings of said recesses are substantially circular.

3. The soft-magnetic, amorphous alloy ribbon according to claim 1 , wherein the height t 2 of said doughnut-shaped projections is 0.5-2 μm.

4. The soft-magnetic, amorphous alloy ribbon according to claim 3 , wherein the height t 2 of said doughnut-shaped projections is 0.5-1.8 μm.

5. The soft-magnetic, amorphous alloy ribbon according to claim 1 , wherein a ratio t 1 /T of the depth t 1 of said recesses to the thickness T of the ribbon is in a range of 0.03-0.15.

6. The soft-magnetic, amorphous alloy ribbon according to claim 1 , wherein the thickness T of said ribbon is 30 μm or less.

7. The soft-magnetic, amorphous alloy ribbon according to claim 1 , wherein a ratio t/T of the total t of the depth t 1 of said recesses and the height t 2 of said doughnut-shaped projections to the thickness T of said ribbon is 0.2 or less.

8. The soft-magnetic, amorphous alloy ribbon according to claim 1 , wherein said soft-magnetic, amorphous alloy ribbon is made of an Fe—Si—B alloy.

9. A magnetic core obtained by laminating or winding the soft-magnetic, amorphous alloy ribbon recited in claim 1 .

10. The magnetic core according to claim 9 , wherein said soft-magnetic, amorphous alloy ribbon is provided with said recesses, and then heat-treated in a magnetic field oriented in a magnetic path direction.

11. A method for producing a soft-magnetic, amorphous alloy ribbon, comprising irradiating a surface of a soft-magnetic, amorphous alloy ribbon produced by a rapid quenching method with laser beam pulses successively in a transverse direction with predetermined longitudinal intervals, to form transverse lines of recesses; the irradiation energy density of said laser beam pulses being controlled, such that (a) a doughnut-shaped projection is formed around each recess, that (b) said doughnut-shaped projections have substantially no molten alloy splashes to have smooth surfaces, that (c) said doughnut-shaped projections have a height t 2 of 2 μm or less, and that (d) a ratio t 1 /T of the depth t 1 of said recesses to the thickness T of said ribbon is in a range of 0.025-0.18, thereby dividing magnetic domains in said amorphous alloy while suppressing increase in the apparent power,
said recesses and said doughnut-shaped projections being constituted by an amorphous phase,
wherein the number density of said recesses in the transverse lines is 2-20/mm, and
wherein a surface of said ribbon to be irradiated with laser beams has reflectance of 15-80% at a wavelength λ of 1000 nm.

12. The method for producing a soft-magnetic, amorphous alloy ribbon according to claim 11 , wherein said amorphous alloy ribbon is irradiated with said laser beam pulses passing through a galvanometer scanner or a polygon scanner and a fθ lens.

13. The method for producing a soft-magnetic, amorphous alloy ribbon according to claim 11 , wherein the irradiation energy density of said laser beam pulses is 5 J/cm 2 or less.

14. The method for producing a soft-magnetic, amorphous alloy ribbon according to claim 13 , wherein the irradiation energy density of said laser beam pulses is 2-5 J/cm 2 .

15. The method for producing a soft-magnetic, amorphous alloy ribbon according to claim 14 , wherein the irradiation energy density of said laser beam pulses is 2.5-4 J/cm 2 .

16. The method for producing a soft-magnetic, amorphous alloy ribbon according to claim 11 , wherein said laser beam pulses are generated by a fiber laser.

Assignees

• Yoshizawa Yoshihito
• Ito Naoki
• Kazui Shinichi
• Sasaki Makoto
• Hitachi Metals Ltd

Inventors

• Yoshizawa Yoshihito
• Ito Naoki
• Kazui Shinichi
• Sasaki Makoto

Classifications

• C22C38/02 Primary

  containing silicon · CPC title

• Y10T428/12389

  having variation in thickness · CPC title

• H01F41/0226

  from amorphous ribbons · CPC title

• Y10T29/49078

  Laminated · CPC title

• H01F1/15341

  Preparation processes therefor · CPC title