Iron cobalt ternary alloy and silica magnetic core

Patent metadata

Field	Value
Publication number	US-10975457-B2
Application number	US-201213565250-A
Country	US
Kind code	B2
Filing date	Aug 2, 2012
Priority date	Aug 2, 2012
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

A magnetic core of superparamagnetic core shell nanoparticles having a particle size of less than 200 nm; wherein the core is an iron cobalt ternary alloy and the shell is a silicon oxide is provided. The magnetic core is a monolithic structure of superparamagnetic core grains of an iron cobalt ternary alloy directly bonded by the silicon dioxide shells. A method to prepare the magnetic core which allows maintenance of the superparamagnetic state of the nanoparticles is also provided. The magnetic core has little core loss due to hysteresis or eddy current flow.

First claim

The invention claimed is:

1. A magnetic core, comprising:
core shell nanoparticles;
wherein
the core is an iron cobalt ternary alloy and the shell is a silicon oxide,
the third component of the ternary alloy is a transition metal selected from the group consisting of scandium, titanium, vanadium, chromium, manganese, nickel, copper and zinc,
the magnetic core is a monolithic structure of superparamagnetic core grains of the iron cobalt ternary alloy having a particle size of 5 to 30 nm directly bonded by the silicon oxide shells, which form a silica matrix, and
the magnetic core is superparamagnetic.

2. The magnetic core according to claim 1 , wherein a space between individual superparamagnetic nano iron cobalt ternary alloy particles is occupied substantially only by the silicon oxide.

3. The magnetic core according to claim 1 , wherein the iron cobalt ternary alloy is an iron cobalt vanadium alloy.

4. The magnetic core according to claim 1 , wherein the iron cobalt ternary alloy is an iron cobalt chromium alloy.

5. The magnetic core according to claim 1 , wherein the silicon oxide is silicon dioxide.

6. The magnetic core according to claim 5 , wherein at least 97% by volume of the space between the iron cobalt ternary alloy grains is occupied by silicon dioxide.

7. An electrical/magnetic conversion device, which comprises the magnetic core according to claim 1 .

8. A vehicle part comprising the electrical/magnetic conversion device according to claim 7 , wherein the part is selected from the group consisting of a motor, a generator, a transformer, an inductor and an alternator.

9. A method to prepare the monolithic magnetic core of claim 1 ,
comprising:
sintering the superparamagnetic core shell particles under heat and pressure under flow of an inert gas to obtain the monolithic structure;
wherein the monolithic core is superparamagnetic.

Assignees

• Rowe Michael Paul
• Toyota Eng & Mfg North America

Inventors

• Rowe Michael Paul

Classifications

• B22F1/056

  Submicron particles having a size above 100 nm up to 300 nm · CPC title

• B22F1/054

  Nanosized particles · CPC title

• C22C33/02 Primary

  by powder metallurgy · CPC title

• H01F3/08

  made from powder (powder coatings on sheets H01F3/02; on strips or ribbons H01F3/04; on wires H01F3/06) · CPC title

• B22F9/24

  starting from liquid metal compounds, e.g. solutions · CPC title