Magneto-sensitive wire for magnetic sensors and production method therefor

Patent metadata

Field	Value
Publication number	US-12013447-B2
Application number	US-201917273541-A
Country	US
Kind code	B2
Filing date	Oct 2, 2019
Priority date	Nov 2, 2018
Publication date	Jun 18, 2024
Grant date	Jun 18, 2024

Abstract

An object is to provide a magneto-sensitive wire that exhibits a stable anisotropic magnetic field even under a high-temperature environment and can achieve expansion of the measurement range of an MI sensor, etc. The present invention provides a magneto-sensitive wire for magnetic sensors that comprises a Co-based alloy having a composite structure in which crystal grains are dispersed in an amorphous phase. The Co-based alloy contains 0.05 to 0.80 at %, preferably 0.10 to 0.60 at %, of Cu with respect to 100 at % of the Co-based alloy as a whole. The Co-based alloy may further contain 65 to 90 at % of the group of magnetic elements consisting of Co, Fe, and Ni as the total, 15 to 27 at % of Si and/or B as the total, and 0.5 to 2.5 at % of Mo. Such a magneto-sensitive wire is excellent in the heat resistance and exhibits a stable anisotropic magnetic field even under a high-temperature environment. By using the magneto-sensitive wire of the present invention, it is possible, for example, to efficiently produce an MI sensor with an expanded measurement range.

First claim

The invention claimed is:

1. A magneto-sensitive wire for magnetic sensors, comprising a Co-based alloy having an amorphous phase,
the Co-based alloy containing, with respect to 100 at % of the Co-based alloy as a whole,
more than 50 at % of Co,
2 to 10 at % of Fe,
0.5 to 2.5 at % of Ni,
15 to 27 at % of Si and B as a total,
0.5 to 2.5 at % of Mo, and
0.05 to 0.80 at % of Cu,
the Co-based alloy having a composite structure in which crystal grains are dispersed in the amorphous phase.

2. The magneto-sensitive wire for magnetic sensors according to claim 1 , wherein at least a part of the crystal grains contains Cu.

3. The magneto-sensitive wire for magnetic sensors according to claim 1 , wherein the Co-based alloy contains 60 at % or more of Co with respect to the Co-based alloy as a whole.

4. The magneto-sensitive wire for magnetic sensors according to claim 3 , wherein the Co-based alloy contains 65 to 90 at % of Co, Fe, and Ni as a total with respect to the Co-based alloy as a whole.

5. The magneto-sensitive wire for magnetic sensors according to claim 4 , wherein the Fe is contained in an amount of 2.5 to 12 at % with respect to the total amount of Co, Fe, and Ni.

6. The magneto-sensitive wire for magnetic sensors according to claim 4 , wherein the Ni is contained in an amount of 1 to 3 at % with respect to the total amount of Co, Fe, and Ni.

7. The magneto-sensitive wire for magnetic sensors according to claim 4 , wherein the Co-based alloy contains 20 to 35 at % of Si and B as a total with respect to the total amount of Co, Fe, and Ni.

8. A method of producing a magneto-sensitive wire for magnetic sensors, comprising
a heat treatment step of heating an amorphous wire comprising a Co-based alloy at a specific temperature equal to or higher than a crystallization start temperature and lower than a crystallization end of the Co-based alloy the Co-based alloy containing with respect to 100 at % of the Co-based alloy as a whole, more than 50 at % of Co, 2 to 10 at % of Fe, 0.5 to 2.5 at % of Ni, 15 to 27 at % of Si and B as a total, 0.5 to 2.5 at % of Mo, and 0.05 to 0.80 at % of Cu,
wherein a magneto-sensitive wire for magnetic sensors that comprises a composite structure in which crystal grains are dispersed in an amorphous phase is obtained.

9. The method of producing a magneto-sensitive wire for magnetic sensors according to claim 8 , wherein the heat treatment step is a tension annealing step performed while applying tensile stress to the amorphous wire.

10. The method of producing a magneto-sensitive wire for magnetic sensors according to claim 8 , wherein the specific temperature is equal to or higher than a first temperature at which the magneto-sensitive wire for magnetic sensors that has an anisotropic magnetic field (Hk) of 10 Oe is obtained.

Assignees

• Aichi Steel Corp

Inventors

• Tatematsu Shunichi
• Shimode Akihiro

Classifications

• H10N50/85

  Materials of the active region · CPC title

• C22C45/04

  with nickel or cobalt as the major constituent · CPC title

• C22F1/10

  of nickel or cobalt or alloys based thereon · CPC title

• H10N50/01

  Manufacture or treatment · CPC title

• C22C19/007

  with a light metal (alkali metal Li, Na, K, Rb, Cs; earth alkali metal Be, Mg, Ca, Sr, Ba, Al Ga, Ge, Ti) or B, Si, Zr, Hf, Sc, Y, lanthanides, actinides, as the next major constituent · CPC title