Magnetic particles and compacts thereof

• US 4,177,089 A
• Filed: 04/24/1978
• Issued: 12/04/1979
• Est. Priority Date: 04/27/1976
• Status: Expired due to Term

• Current Assignee: The Arnold Engineering Co. (The Kattegat Trust Co. Ltd.)
• Original Assignee: The Arnold Engineering Co. (The Kattegat Trust Co. Ltd.)
• Inventors: Bankson, Billye
• Primary Examiner(s): Rutledge, L. Dewayne
• Assistant Examiner(s): Sheehan, John P.
• Application Number:
  US05/899,135
• Time in Patent Office: 589 Days
• Field of Search: 148/104, 148/105, 148/31.55, 252/62.55, 264/DIG. 58, 75/200, 75/201, 75/211, 75/255, 75/230, 75/246, 428/552, 428/428
• US Class Current: 148/309
• CPC Class Codes: H01F 1/24 the particles being insulated
• CPC Class Codes: Y10T 428/12056 Entirely inorganic

Abstract

Magnetic particles and compacts formed therefrom for use as magnetic cores formed of a blend of iron particles and particles of sendust, with the particles containing a coating of an electrical insulator thereon. The particles are compacted and annealed in the practice of this invention to form magnetic cores.

Claims

1. Magnetic powders for compaction into cores consisting essentially of a blend of

(1) 30 to 70% by weight iron particles, and

(2) 70 to 30% by weight particles of an iron alloy consisting essentially of 7 to 13% by weight silicon, 4 to 7% by weight aluminum and the balance being iron,

said particles containing a coating of an electrical insulator thereon to electrically insulate each of the particles from the other.

2. Powders as defined in claim 1 wherein the iron particles are particles of sponge iron.

3. Powders as defined in claim 1 wherein the insulator is an inorganic insulator.

4. Powders as defined in claim 1 wherein the insulator is a blend of an alkali metal silicate and an alkaline eart h metal oxide.

5. Powders as defined in claim 1 wherein the insulator also contains a clay.

6. A magnetic core formed of a blend consisting essentially of (1) 30 to 70% by weight iron particles and (2) 70 to 30% by weight particles of an iron alloy consisting essentially of 7 to 13% by weight silicon, 4 to 7% by weight aluminum and the balance being iron, said particles containing a coating thereon of an electrical insulator and compacted together.

7. A core as defined in claim 6 wherein the iron particles are particles of sponge iron.

8. A core as defined in claim 6 wherein the insulator is an inorganic insulator.

9. A core as defined in claim 6 wherein the insulator is a blend of an alkali metal silicate and an alkaline earth metal oxide.

10. A core as defined in claim 9 wherein the insulator also contains a clay.

11. A magnetic core formed of a blend consisting essentially of (1) 30 to 70% by weight iron particles and (2) 70 to 30% by weight particles of an iron alloy consisting essentially of 7 to 13% by weight silicon, 4 to 7% by weight aluminum and the balance being iron, said particles containing a coating thereof of an electrical insulator and having been compacted together at a pressure within the range of 60 to 140 tons/sq.in. and annealed in a hydrogen-containing atmosphere at a temperature within the range of 1000°

to 1500°

F.

12. A core as defined in claim 11 wherein the insulator is a blend of an alkali metal silicate and an alkaline earth metal oxide.

13. A core as defined in claim 12 wherein the insulator also contains a clay.