FE-BASED SOFT MAGNETIC ALLOY AND METHOD FOR MANUFACTURING THE SAME

• US 20200135370A1
• Filed: 10/21/2019
• Published: 04/30/2020
• Est. Priority Date: 10/25/2018
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kang, Dongwon, Kim, Joungwook, Kim, Jin Bae
• Granted Patent: US 11,651,879 B2
• Time in Patent Office: Days
• CPC Class Codes: C21D 1/74 Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
• CPC Class Codes: C21D 1/76 Adjusting the composition of the atmosphere
• CPC Class Codes: C21D 2201/03 Amorphous or microcrystalline structure
• CPC Class Codes: C21D 6/00 Heat treatment of ferrous alloys
• CPC Class Codes: C21D 8/1211 Rapid solidification; Thin strip casting
• CPC Class Codes: C21D 8/1244 the heat treatment(s) being of interest
• CPC Class Codes: C22C 2202/02 Magnetic
• CPC Class Codes: C22C 38/02 containing silicon
• CPC Class Codes: C22C 38/06 containing aluminium
• CPC Class Codes: C22C 38/12 containing tungsten, tantalum, molybdenum, vanadium, or niobium
• CPC Class Codes: C22C 38/16 containing copper
• CPC Class Codes: C22C 38/60 containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
• CPC Class Codes: C22C 45/02 with iron as the major constituent
• CPC Class Codes: H01F 1/15308 based on Fe/Ni H01F1/15325 takes precedence
• CPC Class Codes: H01F 1/15333 containing nanocrystallites, e.g. obtained by annealing
• CPC Class Codes: H01F 1/15341 Preparation processes therefor

Abstract

The present disclosure relates to an iron (Fe)-based amorphous soft magnetic alloy and a method for manufacturing the soft magnetic alloy. According to the present disclosure, there is provided an Fe-based soft magnetic alloy including C and S meeting 1≥a+b≥6, wherein a is an atomic % content of C and b is an atomic % content of S, B meeting 4.5≥x≥13.0, wherein x is an atomic % content of B, Cu meeting 0.2≥y≥1.5, wherein y is an atomic % content of Cu, Al meeting 0.5≥z≥2, wherein z is an atomic % content of Al, and a remaining atomic % content of Fe and other inevitable impurities, wherein the Fe-based soft magnetic alloy includes a micro-structure, and wherein the micro-structure includes a crystalline phase with a mean crystalline grain size ranging from 15 nm to 50 nm in an amorphous base.

Claims

1. An iron (Fe)-based soft magnetic alloy, comprising:

carbon (C) and sulfur (S) meeting 1≥

a+b≥

6, wherein a is an atomic % content of C and b is an atomic % content of S;

boron (B) meeting 4.5≥

x≥

13.0, wherein x is an atomic % content of B;

copper (Cu) meeting 0.2≥

y≥

1.5, wherein y is an atomic % content of Cu;

aluminum (Al) meeting 0.5≥

z≥

2, wherein z is an atomic % content of Al; and

a remaining atomic % content of Fe and other inevitable impurities, wherein

the Fe-based soft magnetic alloy includes a micro-structure, and wherein the micro-structure includes a crystalline phase with an average grain size ranging from 15 nm to 50 nm in an amorphous base.

2. The Fe-based soft magnetic alloy of claim 1, wherein b is 0.3*a or less.

3. The Fe-based soft magnetic alloy of claim 1, wherein a ratio of a to b is (0.9 to 7):

(0.1 to 0.3), and wherein saturation magnetic flux density is 1.71 T or more.

4. The Fe-based soft magnetic alloy of claim 3, wherein a coercive force of the alloy is 2.25 Oe or less.

5. The Fe-based soft magnetic alloy of claim 1, further comprising at least one of niobium (Nb), vanadium (V), and tantalum (Ta) which partially substitute Cu.

6. The Fe-based soft magnetic alloy of claim 5, wherein a proportion of Nb, V, or Ta substituting Cu is 20% or less of the entire content of Cu.

7. The Fe-based soft magnetic alloy of claim 1, further comprising silicon (Si) and/or phosphorus (P) which partially substitute B.

8. The Fe-based soft magnetic alloy of claim 7, wherein a proportion of Si substituting B is 30% or less of the entire content of B.

9. The Fe-based soft magnetic alloy of claim 7, wherein a proportion of P substituting B is 10% or less of the entire content of B.

10. The Fe-based soft magnetic alloy of claim 1, wherein the average grain size of the crystalline phase ranges from 30 nm to 50 nm.

11. A method for manufacturing an Fe-based soft magnetic alloy, the method comprising:

melting an Fe-based mother alloy including C and S meeting 1≥

a+b≥

6, wherein a is an atomic % content of C and b is an atomic % content of S, B meeting 4.5≥

x≥

13.0, wherein x is an atomic % content of B, Cu meeting 0.2≥

y≥

1.5, wherein y is an atomic % content of Cu, Al meeting 0.5≥

z≥

2, wherein z is an atomic % content of Al, and a remaining atomic % content of Fe and other inevitable impurities;

forming an amorphous micro-structure by quenching the melted mother alloy; and

forming a crystalline phase by performing thermal treatment on the amorphous micro-structure.

12. The method of claim 11, wherein in the melting, among the components of the mother alloy, using one or more compounds of Al₂S₃, Cu₂S, and FeS as a precursor of S.

13. The method of claim 11, wherein the melting includes using arc re-melting or induction melting.

14. The method of claim 11, wherein forming the amorphous micro-structure includes using melt-spinning at a spinning speed ranging from 50 m/s to 70 m/s.

15. The method of claim 14, wherein the melt-spinning includes producing an alloy having a thickness ranging from 0.025 mm to 0.030 mm.

16. The method of claim 11, wherein forming the crystalline phase by performing thermal treatment includes heating at a rate of 15°

C./min.

17. The method of claim 11, wherein forming the crystalline phase by performing thermal treatment includes maintaining a temperature from 350°

C. to 500°

C.

18. The method of claim 11, wherein forming the crystalline phase by performing thermal treatment includes performing treatment from 30 minutes to 60 minutes.

19. The method of claim 11, wherein forming the crystalline phase by performing thermal treatment includes maintaining an argon (Ar)-pressurized atmosphere ranging from an atmospheric pressure to 0.3 MPa.

20. The method of claim 11, wherein forming the crystalline phase by performing thermal treatment includes at least one of heating at a rate of 15°

C./min;

maintaining a temperature from 350°

C. to 500°

C.;

performing treatment from 30 minutes to 60 minutes; and

maintaining an argon (Ar)-pressurized atmosphere ranging from an atmospheric pressure to 0.3 MPa.