# US 11,078,561 B2 · Soft magnetic material and method for producing the same

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- Number: US 11,078,561 B2
- Document ID: US11078561B2
- Status: Granted
- Kind: B2
- Application number: 16/417,786
- Filed: 2019-05-21
- Published: 2019-12-05
- Granted: 2021-08-03
- Earliest claimed: 2018-05-30
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Applicants: Toyota Jidosha Kabushiki Kaisha
- Inventors: Kiyotaka Onodera; Hidefumi Kishimoto
- Web page: https://patentgrep.com/patent/US11078561B2

## CPC

- C22C 45/04: with nickel or cobalt as the major constituent
- C22C 33/003: {making amorphous alloys}
- C22C 45/02: with iron as the major constituent
- H01F 1/15308: {based on Fe/Ni (H01F1/15325 takes precedence)}
- H01F 1/15333: {containing nanocrystallites, e.g. obtained by annealing}
- C22C 2200/02: Amorphous
- C22C 2202/02: Magnetic
- C22C: ALLOYS (treatment of alloys C21D, C22F)
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES

## Abstract

There are provided a soft magnetic material having a high saturation magnetization and a low coercive force and excellent in thermal endurance, and a method for producing the same. The present disclosure relates to a soft magnetic material represented by the following composition formula: Fe100-x-yBxNiy, wherein x satisfies 10≤x≤16 in at %, and y satisfies 0<y≤4 in at %, having a coercive force of 20 A/m or less, and having a coercive force characteristic decrease rate after a thermal endurance test {[(coercive force after thermal endurance test−coercive force before thermal endurance test)/coercive force before thermal endurance test]×100 (%)} of 20% or less, wherein the thermal endurance test is carried out by allowing the soft magnetic material to stand in a constant temperature oven at 170° C. in the air for 100 h, and a method for producing the same.

## Claims

### Claim 1

A soft magnetic material represented by the following composition formula:
Fe100-x-yBxNiy
wherein x satisfies 10≤x≤16 in at %, y satisfies 0<y≤4 in at %, part of B may be replaced by at least one element selected from the group consisting of Si, P, and C, the replaced B is 3 at % or less based on an entire composition, part of Fe and part of Ni may be replaced by at least one element selected from Nb, Co, Zr, Hf, Cu, Ag, Au, Zn, Sn, As, Sb, Bi, Y, and rare earth elements, and the replaced Fe and Ni is 3 at % or less based on the entire composition,
having a coercive force of 20 A/m or less, and
having a coercive force characteristic decrease rate after a thermal endurance test {[(coercive force after thermal endurance test−coercive force before thermal endurance test)/coercive force before thermal endurance test]×100 (%)} of 20% or less, wherein the thermal endurance test is carried out by allowing the soft magnetic material to stand in a constant temperature oven at 170° C. in the air for 100 h.

### Claim 2 (depends on 1)

The soft magnetic material according to claim 1, wherein 12≤x≤14 in at %.

### Claim 3 (depends on 1)

The soft magnetic material according to claim 1, wherein 1≤y≤4 in at %.

### Claim 4

A method for producing a soft magnetic material, comprising:
providing an alloy having a composition represented by the following composition formula:
Fe100-x-yBxNiy
wherein x satisfies 10≤x≤16 in at %, y satisfies 0<y≤4 in at %, part of B may be replaced by at least one element selected from the group consisting of Si, P, and C, the replaced B is 3 at % or less based on an entire composition, part of Fe and part of Ni may be replaced by at least one element selected from Nb, Co, Zr, Hf, Cu, Ag, Au, Zn, Sn, As, Sb, Bi, Y, and rare earth elements, and the replaced Fe and Ni is 3 at % or less based on the entire composition,
and having an amorphous phase; and
heat-treating the alloy under conditions in which the alloy is heated at a heating rate of 10° C./s or more to a temperature region of {T1+0.88(T2−T1)} or more to less than T2, wherein T1 is an α-Fe crystal formation start temperature, and T2 is a Fe—B compound formation start temperature, and held in the temperature region for a holding time of 0 to 80 s.

### Claim 5 (depends on 4)

The method according to claim 4, wherein a molten metal is quenched to provide the alloy.

### Claim 6 (depends on 4)

The method according to claim 4, wherein the heating rate is 125° C./s or more.

### Claim 7 (depends on 5)

The method according to claim 5, wherein the heating rate is 125° C./s or more.

### Claim 8 (depends on 4)

The method according to claim 4, wherein the heating rate is 325° C./s or more.

### Claim 9 (depends on 5)

The method according to claim 5, wherein the heating rate is 325° C./s or more.

### Claim 10 (depends on 4)

The method according to claim 4, wherein the holding time is 3 s to 10 s.

### Claim 11 (depends on 5)

The method according to claim 5, wherein the holding time is 3 s to 10 s.

### Claim 12 (depends on 6)

The method according to claim 6, wherein the holding time is 3 s to 10 s.

### Claim 13 (depends on 8)

The method according to claim 8, wherein the holding time is 3 s to 10 s.

### Claim 14 (depends on 4)

The method according to claim 4, wherein the heat treatment is carried out by sandwiching the alloy between heated blocks.

### Claim 15 (depends on 5)

The method according to claim 5, wherein the heat treatment is carried out by sandwiching the alloy between heated blocks.

### Claim 16 (depends on 6)

The method according to claim 6, wherein the heat treatment is carried out by sandwiching the alloy between heated blocks.

### Claim 17 (depends on 8)

The method according to claim 8, wherein the heat treatment is carried out by sandwiching the alloy between heated blocks.

### Claim 18 (depends on 10)

The method according to claim 10, wherein the heat treatment is carried out by sandwiching the alloy between heated blocks.

### Claim 19 (depends on 4)

The method according to claim 4, wherein 12≤x≤14 in at %.

### Claim 20 (depends on 4)

The method according to claim 4, wherein 1≤y≤4 in at %.