Alloy composition, Fe-based nano-crystalline alloy and forming method of the same

Patent metadata

Field	Value
Publication number	US-9287028-B2
Application number	US-201013392441-A
Country	US
Kind code	B2
Filing date	Jul 20, 2010
Priority date	Aug 24, 2009
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

An alloy composition of Fe (100-X-Y-Z) B X P Y Cu z , where 4≦X≦14 atomic %, 0<Y≦10 atomic %, and 0.5≦Z≦2 atomic %. This alloy composition has an amorphous phase as a main phase. This alloy composition is used as a starting material and exposed to a heat-treatment so that nanocrystals comprising no more than 25 nm of bccFe can be crystallized. Thus, an Fe-based nano-crystalline alloy having superior magnetic properties can be obtained.

First claim

What is claimed is:

1. An Fe-based nanocrystalline alloy formed from an alloy composition of the formula Fe (100-X-Y-Z) B X P Y Cu z having an amorphous phase as a main phase, wherein 79≦100-X-Y-Z≦86 atomic %, 4≦X≦9 atomic %, 1≦Y≦10 atomic %, and 0.5≦Z<1.2 atomic %,
wherein the alloy composition has a first crystallization start temperature (T x1 ) and a second crystallization start temperature (T x2 ) which have a difference (ΔT=T x2 −T x1 ) of 70 to 200° C.,
wherein the Fe-based nanocrystalline alloy is formed by heating the alloy composition to a temperature in a range of T x1 −50° C. to T x2 −77° C.,
wherein nanocrystals of the Fe-based nanocrystalline alloy have an average diameter of 5 to 25 nm existing in the amorphous phase, and
wherein the Fe-based nano-crystalline alloy has coercivity of 20 A/m or less and a saturation magnetic flux density of 1.6 T or more.

2. The Fe-based nanocrystal alloy according to claim 1 , wherein in the alloy composition, X, Y and Z are defined as follows: 82≦100-X-Y-Z≦86 atomic %, 6≦X≦9 atomic %, 2≦Y≦8 atomic %, and 0.5≦Z<1.2 atomic %.

3. The Fe-based nanocrystal alloy according to claim 1 , wherein in the alloy composition a ratio of Z to Y is defined as follows: 0.1≦Z/Y<1.2.

4. The Fe-based nanocrystal alloy according to claim 1 , wherein the alloy composition has a continuous strip shape.

5. The Fe-based nanocrystal alloy according to claim 4 , wherein the alloy composition is flat on itself when subjected to a 180 degree bend test.

6. The Fe-based nanocrystal alloy according to claim 1 , wherein the alloy composition is formed in a powder form.

7. The Fe-based nanocrystal alloy according to claim 1 , wherein the alloy composition has a melting temperature (Tm) of 1150° C. or less.

8. The Fe-based nanocrystal alloy according to claim 1 , wherein the alloy composition has initial nanocrystals having an average diameter of 0.3 to 10 nm.

9. A method of forming an Fe-based nano-crystalline alloy, the method comprising:
preparing the alloy composition according to claim 1 , and
subjecting the alloy composition to heating at a temperature in the range of T x1 −50° C. to T x2 −77° C.

10. The Fe based nano-crystalline alloy according to claim 1 , wherein the Fe-based nano-crystalline alloy has a saturation magnetostriction of 15×10 −6 or less.

Assignees

• Urata Akiri
• Yamada Yasunobu
• Matsumoto Hiroyuki
• Yoshida Shigeyoshi
• Makino Akihiro
• Nec Tokin Corp
• Univ Tohoku

Inventors

• Urata Akiri
• Yamada Yasunobu
• Matsumoto Hiroyuki
• Yoshida Shigeyoshi
• Makino Akihiro

Classifications

• B22F1/065

  Spherical particles · CPC title

• C21D6/00

  Heat treatment of ferrous alloys · CPC title

• C22C33/003

  making amorphous alloys · CPC title

• B22F1/0048

  Operations & Transport · mapped topic

• H01F1/15333

  containing nanocrystallites, e.g. obtained by annealing · CPC title