Nanocrystalline magnetic alloy and method of heat-treatment thereof

Patent metadata

Field	Value
Publication number	US-2016196907-A1
Application number	US-201514591478-A
Country	US
Kind code	A1
Filing date	Jan 7, 2015
Priority date	Jan 7, 2015
Publication date	Jul 7, 2016
Grant date	—

Abstract

A nanocrystalline alloy ribbon has an alloy composition represented by FeCu x B y Si z A a X b where 0.6≦x<1.2, 10≦y≦20, 0<z≦10, 10≦(y+z)≦24, 0≦a≦10, 0≦b≦5, with the balance being Fe and incidental impurities, where A is an optional inclusion of at least one element selected from Ni, Mn, Co, V, Cr, Ti, Zr, Nb, Mo, Hf, Ta and W, and X is an optional inclusion of at least one element selected from Re, Y, Zn, As, In, Sn, and rare earth elements, all numbers being in atomic percent. The ribbon has a local structure having nanocrystals with average particle sizes of less than 40 nm dispersed in an amorphous matrix, the nanocrystals occupying more than 30 volume percent of the ribbon and has a radius of ribbon curvature of at least 200 mm.

First claim

What is claimed is:

1 . A nanocrystalline alloy ribbon comprising:
an alloy composition represented by FeCu x B y Si z A a X b where 0.6≦x<1.2, 10≦y≦20, 0<z≦10, 10≦(y+z)≦24, 0≦a≦10, 0≦b≦5, with the balance being Fe and incidental impurities, where A is an optional inclusion of at least one element selected from Ni, Mn, Co, V, Cr, Ti, Zr, Nb, Mo, Hf, Ta and W, and X is an optional inclusion of at least one element selected from Re, Y, Zn, As, In, Sn, and rare earth elements, all numbers being in atomic percent; a local structure having nanocrystals with average particle sizes of less than 40 nm dispersed in an amorphous matrix, the nanocrystals occupying more than 30 volume percent of the ribbon; and a radius of ribbon curvature of at least 200 mm.

2 . The nanocrystalline alloy ribbon according to claim 1 , having a B 80 /B s ratio of 0.92 to 0.98, where B 80 is magnetic induction at 80 A/m.

3 . The nanocrystalline alloy ribbon according to claim 1 , having a magnetic induction at 80 A/m exceeding 1.6 T, a saturation induction B s exceeding 1.7 T, and a coercivity H c of less than 6.5 A/m.

4 . The nanocrystalline alloy ribbon according to claim 1 , having been heat treated and exhibiting a core loss at 1.5 T and 50 Hz of less than 0.27 W/kg.

5 . The nanocrystalline alloy ribbon according to claim 1 , wherein the content of Fe exceeds 75 atomic percent.

6 . The nanocrystalline alloy ribbon according to claim 1 , wherein the alloy composition consists of the elements Fe, Cu, B, and Si and incidental impurities.

7 . The nanocrystalline alloy ribbon according to claim 1 , wherein “a” ranges from 0.01 atomic percent to 10 atomic percent;.

8 . The nanocrystalline alloy ribbon according to claim 7 , wherein “a” ranges from 0.01 atomic percent to 1.5 atomic percent.

9 . The nanocrystalline alloy ribbon according to claim 2 , wherein a collective content of Nb, Zr, Ta and Hf in the alloy composition is below 0.4.

10 . The nanocrystalline alloy ribbon according to claim 1 , wherein b is less than 2.0 atomic percent.

11 . The nanocrystalline alloy ribbon according to claim 1 , wherein b is less than 1.0 atomic percent.

12 . The nanocrystalline alloy ribbon according to claim 1 , having been heat-treated first by an average heating rate of more than 50° C./sec. from at least room temperature.

13 . The nanocrystalline alloy ribbon according to claim 12 , having been heat-treated first by the average heating rate of more than 50° C./sec. from 300° C. to a predetermined holding temperature which exceeds 450° C. and which is less than 520° C., with the holding time of less than 10 minutes.

14 . The nanocrystalline alloy ribbon according to claim 12 , having been treated using a magnetic field applied during the heat-treatment, the field applied being high enough to magnetically saturate the ribbon and being in DC, AC or pulse form, and the direction of the applied field is predetermined depending on the need for a square, round or linear BH loop.

15 . The nanocrystalline alloy ribbon according to claim 12 , having been produced with a mechanical tension higher than 1 MPa and less than 500 MPa applied to the ribbon.

16 . The nanocrystallline alloy ribbon according to claim 12 , having been treated with a secondary heat-treatment performed at a temperature between 400° C. and 500° C. for a duration shorter than 30 minutes.

17 . A method comprising:
heating a nanocrystalline alloy ribbon at an average heating rate of more than 50° C./sec. from room temperature or higher to a predetermined holding temperature ranging from 430° C. to 530° C., the ribbon having an alloy composition represented by FeCu x B y Si z A a X b where 0.6≦x<1.2, 10≦y≦20, 0<z≦10, 10≦(y+z)≦24, 0≦a≦10, 0≦b≦5, with the balance being Fe and incidental impurities, where A is an optional inclusion of at least one element selected from Ni, Mn, Co, V, Cr, Ti, Zr, Nb, Mo, Hf, Ta and W, and X is an optional inclusion of at least one element selected from Re, Y, Zn, As, In, Sn, and rare earth elements, all numbers being in atomic percent; and holding the ribbon at the holding temperature for less than 90 minutes.

18 . The method according to claim 17 , wherein the heating rate ranges from 80 to 100° C./sec.

19 . The method according to claim 17 , wherein the combined duration of the heating and the holding is from 3 to 15 seconds.

20 . The method according to claim 17 , wherein a magnetic field is applied during the heating, the field applied being high enough to magnetically saturate the ribbon and being preferably higher than 0.8 kA/m either in DC, AC or pulse form, and the direction of the applied field is predetermined depending on the need for a square, round or linear BH loop;

21 . The method according to claim 17 , wherein a mechanical tension ranging from 1 to 500 MPa is applied during the heating.

22 . The method according to claim 17 , wherein the heating is performed in an environment having an oxygen gas content between 6% and 18%.

23 . The method according to claim 17 , wherein the oxygen gas content is between 9% and 13%.

24 . The method according to claim 17 , further comprising:
after the heating, performing a second heating at a temperature between 400° C. and 500° C. for a duration of 30 minutes or shorter.

Assignees

• Metglas Inc
• Hitachi Metals Ltd

Inventors

• Ohta Motoki
• Ito Naoki

Classifications

• C22C38/02

  containing silicon · CPC title

• C21D8/125

  with application of tension · CPC title

• C22C45/02

  with iron as the major constituent · CPC title

• C22C38/16

  containing copper · CPC title

• C21D1/18

  Hardening (C21D1/02 takes precedence); Quenching with or without subsequent tempering (quenching devices C21D1/62) · CPC title