JPH03215650A - Ultrafine crystalline alloy having perminvar properties and its manufacture - Google Patents

Abstract

PURPOSE:To provide a ultrafine crystalline alloy with certain magnetic permeability in a low exciting magnetic field and to improve its perminvar properties by subjecting an amorphous alloy consisting essentially of Fe, an A group (Cu, Ag and Au) and an M group (Nb, W, Ta or the like) to heat treatment under specified conditions. CONSTITUTION:An amorphous alloy consisting essentially of Fe, an A group (at least one kind from among Cu, Ag and Au) and an M group (at least one kind from among Nb, W, Ta, Zr, Hf, Ti, V, Mn, Cr and Mo) is manufactured. This alloy is subjected to heat treatment in an atmosphere of a nitrogen gas or the like to convert at least >=50% of the crystals in the structure into fine ones having <=1000Angstrom average grain size. Next, the alloy is subjected to heat treatment at the Curie temp. or below of a bccFe solid soln. phase formed by crystallization. In this way, the ultrafine crystalline alloy showing perminvar properties having a constricted hysteresis loop, having high magnetic permeability and excellent in stability can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an alloy consisting of an ultra-fine grain structure with perminbar characteristics having a relatively constant magnetic permeability and a constricted hysteresis loop at low excitation magnetic fields. It concerns its manufacturing method.

[Prior Art] Fe--Ni--Co based perminver alloys have been known as alloys that have a relatively constant magnetic permeability in a region where the excitation magnetic field is low. These alloys are usually crystalline;
Typical composition is 20%It%Fe-60tzt%C
o-20wt%Ni and 30wt%Fe-25wt%Co
-45wt%Ni etc. are known. Typical characteristics are DC coercive force Hc of 0.50e and initial magnetic permeability μ. is 100,
The residual magnetic flux density is 7.5 kG (7.5 wt% Mo-
45wt%Ni-25wtlCo-22.5wt%Fe
).

In recent years, Co-F has also been shown to exhibit such properties.
An e-Ni-based amorphous alloy has been reported (Japanese Unexamined Patent Publication No. 170446/1982). According to this, Bs is 0.
5T (5kG) ~1. OT (10 kG) and a magnetic permeability μ of about 2,000 to 30,000 in a region with a low excitation magnetic field have been obtained.

By the way, alloys that exhibit such verminvar characteristics are:
Very useful as various sensor materials.

For example, since it exhibits a relatively constant magnetic permeability in a low excitation magnetic field region, it can be used in current sensors that detect weak currents. Furthermore, since it exhibits a nonlinear hysteresis curve, when it is excited and magnetized at a high frequency, harmonics are generated, which can be detected and used as anti-theft sensors. For these applications, it is necessary not only to exhibit a relatively constant magnetic permeability in the low magnetic field region, but also to exhibit a magnetic permeability as high as possible in the low excitation magnetic field from the viewpoint of sensitivity.

In addition, from the viewpoint of reliability, it is also required that the change over time is small. Furthermore, a high saturation magnetic flux density is also important in terms of miniaturization of components.

[Problems to be Solved by the Invention] However, conventional crystalline Perminvar alloys are
Since c is large, the magnetic permeability μ in the low magnetic field region. There is a problem that the sensitivity is low and sufficient sensitivity cannot be obtained. On the other hand, in the case of an amorphous alloy that exhibits perminvar characteristics, μ. Although it has a large value, it has poor thermal stability and stability over time, making it unsuitable for applications where harsh conditions or changes in properties are averse. Further, the saturation magnetic flux density is less than IT (10 kG) in the case of the amorphous alloy mentioned above, which is not sufficient.

[Means for Solving the Problems] In order to solve the above problems, the present inventors, as a result of intensive studies, found that Fe, A (at least one element selected from the group consisting of Cu, Ag and Au) and M (but A is N)
b, W, Ta, Zr, Hf, Ti, W, Mn, Cr, and MO) as an essential element, and at least 50% of the structure has an average grain size of 1000 grains or less. An alloy consisting of fine crystal grains is produced by producing an amorphous alloy with the above composition, heating it, and heat-treating it so that at least 50% of the structure becomes fine crystals with an average grain size of 1000 grains or less. bc formed by
Relatively constant magnetic permeability μ at low excitation magnetic fields when produced by heat treatment at temperatures below the Curie temperature of the cFe solid solution phase. The present inventors have discovered that an alloy exhibiting perminver characteristics with a constricted hysteresis loop can be obtained, and have conceived the present invention.

In the present invention, A (at least one element selected from the group consisting of Cu, Ag and Au) and M (where X is Zr, Hf, Ti, V, Mn)
, Cr, and Mo) are essential elements. Due to the combined addition effect of A and H, the structure is significantly refined, and an alloy with high magnetic permeability and excellent stability is obtained, which exhibits perminbar characteristics with a relatively constant magnetic permeability and a constricted hysteresis loop in a low excitation magnetic field. . At least 50% of the structure must consist of fine crystal grains with an average grain size of 1000 grains or less.

This is because when the crystal grain content is less than 50% and the grain size is 1000 or more, the soft magnetic properties deteriorate, and even if Verminvar properties are exhibited, the initial magnetic permeability μ is low. This is because the thermal stability and stability over time are also poor, which is not preferable. The average particle size is more preferably 500 or less, particularly preferably 2
From 0 to 200 people. A typical alloy composition is as follows: (Fe1-aMa) x na -x-F-z-(X-
4-yA, SxyB, M'al'l'axy(at
%) (However, in the old case, it was Co and/or Ni, and A was Cu,
at least one element selected from Ag, Au; at least one element selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti, W, Mn, Cr and MO;
κ″ is Al, platinum group element, Sc, Y, Zn, Sn, Re
At least one element selected from the group consisting of, X is C
, Ge, P, Ga, Sb, In, Be, As, and a, X+V
+Z+C1tβ and γ are O≦a≦0.5, 0.
1≦x≦3, 0≦y≦30, 0≦2≦25, 5≦y+z
≦30.0.1≦α≦30.0≦β≦10, 0≦γ≦1
Fills 0. ). Although the remainder of the structure is usually amorphous, similar properties can be obtained with substantially crystalline alloys.

Another aspect of the present invention includes a step of manufacturing an amorphous alloy having the above composition, a step of heating the amorphous alloy so that at least 50% of the structure becomes fine crystals with an average grain size of 1000 grains or less, and A relatively constant magnetic permeability μ in a low excitation magnetic field, characterized by comprising a step of heat-treating the bccFe solid solution phase formed by oxidation at a temperature below the Curie temperature.
. and a method for producing an ultrafine crystalline alloy having perminver characteristics with a constricted hysteresis loop.

In the ultrafine-crystalline alloy produced by the above manufacturing method, the magnetic permeability μ is relatively constant at a low excitation magnetic field. It is possible to produce an alloy that has perminver characteristics with a constricted hysteresis loop, has a high initial magnetic permeability, and has excellent stability. The initial heat treatment is performed to refine the structure and obtain excellent soft magnetic properties, thermal stability, and stability over time.The heat treatment performed below the Curie temperature of the bccFe solid solution results in a relatively constant magnetic permeability μ.

This is done in order to obtain vermin bar characteristics with a constricted hysteresis loop. A more preferable heat treatment condition at a temperature below the Curie temperature is 300° C. or above for 4 hours or more.

Particularly excellent perminver properties can be obtained within this range. Further, perminbar properties are more easily obtained than in the case of alloys containing elements such as Co and Nu.

The reason why a constricted B-H curve is obtained is not fully clear, but the following reasons can be considered.

When an alloy that has crystallized into fine grains is heat-treated below the Curie temperature, the constituent atoms are arranged anisotropically in the direction of the internal magnetic field that reflects the magnetic domain structure of the alloy, resulting in induced magnetic anisotropy. For this reason, it is thought that fixation of magnetic domains occurs, and a region that is difficult to magnetize when a magnetic field is applied in a certain direction is formed in the alloy, causing the alloy to exhibit perminbar characteristics. but,
Such anisotropy hardly occurs in the case of the alloy of the present invention near room temperature, and it is significantly more stable than an amorphous alloy. In the case of amorphous alloys, the properties change even at low temperatures around 100° C., resulting in lack of stability and impractical use.

[Examples] The present invention will be described below based on Examples, but the present invention is not limited thereto.

Example 1 Cul. 2%, Nb2.9%SL13.7%,
A molten alloy consisting essentially of 88.8% Fe was rapidly cooled by a single roll method to produce an amorphous alloy ribbon having a thickness of 17 μm and a width of 2 mm.

Next, this alloy ribbon was cut into a length of 100 mm.

Next, this magnetic core was heat treated at 570° C. for 1 hour in a nitrogen gas atmosphere. After the heat treatment, the alloy was observed using a transmission electron microscope, and it was confirmed that ultrafine crystals with a crystal grain size of approximately 100 nm accounted for most of the structure. The Curie temperature of the bccFe phase, which is the main phase, was about 570°C.

The alloy after this heat treatment was then held at 450° C. for 12 hours to produce an alloy of the present invention, and its DC B-H curve was measured.

The results obtained are shown in FIG.

It can be seen that it shows a constricted hysteresis curve and exhibits perminver characteristics. Furthermore, it can be seen that the coercive force is small and the initial magnetic permeability is high and excellent.

Furthermore, the saturation magnetic flux density is 12 kG or more, which is superior to Co-based amorphous alloys.

Example 2 Atomic % tecul. 1%, Nb3.2%, Si13.0%
, 85.1%, Mo 0.6%, and the balance substantially Fe was rapidly cooled by a single roll method to produce an amorphous alloy having a plate thickness of 16 μm and a width of 1.5 mm. Next, this alloy was cut into 150+ am pieces and heated at 575°C in a nitrogen gas atmosphere at 45°C.
Heat treated for minutes. After the heat treatment, the alloy was observed using a transmission electron microscope, and it was confirmed that ultrafine crystals with a crystal grain size of approximately 100 nm accounted for most of the structure. The Curie temperature of the bccFe phase, which is the main phase, was about 570'C. Next, the heat treated alloy was heat treated for 12 hours at the heat treatment temperature shown in FIG. FIG. 2 shows the DC B-H curve after heat treatment.

In particular, it can be seen that in the case of heat treatment at 300° C. or higher, the hysteresis curve becomes significantly constricted and exhibits remarkable perminbar characteristics.

Example 3 Atomic % TeA u 1 . O%, Nb3.4%Si1
A molten alloy consisting of 3.7%, 89.2%, V0.6% and the remainder substantially Fe was rapidly cooled by a single roll method to form a plate with a thickness of 16 μm.
An amorphous alloy with a width of 1.1+n+n and a width of 1.1+n+n was produced. Next, this alloy was cut into 140 mm pieces and 580 mm was cut into 140 mm pieces in an Ar gas atmosphere.
Heat treatment was performed at ℃ for 40 minutes. After the heat treatment, the alloy was observed using a transmission electron microscope, and it was confirmed that ultrafine crystals with a crystal grain size of approximately 100 nm accounted for most of the structure. The Curie temperature of the main phase, bccFe phase, is approximately 570°C
Met. Next, the heat-treated alloy was heat-treated for the heat treatment time shown in FIG. The heat treatment temperature was 400°C, which is lower than the Curie temperature. The DC B-H curve after heat treatment is the third
As shown in the figure.

Example 4 Amorphous alloys having the compositions shown in Table 1 were produced by a single roll method and a sputtering method, and after a crystallization heat treatment, a heat treatment was performed at 450° C. for 4 hours. After the heat treatment, the alloy was observed using a transmission electron microscope, and it was confirmed that ultrafine crystals with a crystal grain size of approximately 100 nm accounted for most of the structure.

Table 1 Next, this alloy was heat treated below the Curie temperature, and the direct current B
-H curve and magnetic permeability μ. was measured. The alloy after heat treatment exhibited perminver characteristics similar to Example 1. This alloy is then held at 150°C and its initial magnetic permeability μ. . , and μ after 100 hours. 100 was measured.

Initial permeability μ. . , and μ after 100 hours. 100 ratio μ. . /μo100 is shown.

The alloy of the present invention has a smaller μ than conventional amorphous alloys. . /μ.

The value of 100 is close to 1 and stable. Also, the μ is significantly smaller than that of conventional crystalline materials. It can be seen that this method is more suitable for magnetic applications because the sensitivity can be increased.

[Effects of the Invention] According to the present invention, an ultrafine-crystalline alloy exhibiting perminver characteristics with relatively constant magnetic permeability and a constricted hysteresis loop in a low excitation magnetic field, and exhibiting high magnetic permeability and excellent stability, and a method for producing the same are provided. The effect is remarkable because it can provide the following.

[Brief Description of the Drawings] Figure 1 is a diagram showing an example of the DC B-H curve of the alloy of the present invention, and Figure 2 is a diagram showing changes in the DC B-1 curve of the alloy according to the present invention No. J depending on the heat treatment temperature. FIG. 3 is a diagram showing changes in the DC B-H curve of the alloy according to the present invention depending on the heat treatment time. Figure 1 Figure 2 Figure 3 Figure 3 Procedural Amendments” (Spontaneous) May 22, 1990 To the Commissioner of the Special Agency for Special Agents 1, Indication of Matter A’1 Patent Application No. 27091 No. 3 2, Invention Ultrafine crystal base metal with perminbar properties and its manufacture 1
Person 3, supplementary [I:. Relationship with 1.

Claims (6)

[Claims] (1) Fe, A (at least one element selected from the group consisting of Cu, Ag, and Au) and M (where M is N
b, W, Ta, Zr, Hf, Ti, V, Mn, Cr, and Mo) as an essential element, and at least 50% of the structure is fine with an average grain size of 1000 Å or less An ultrafine-crystalline alloy characterized by having relatively constant magnetic permeability in a low excitation magnetic field and perminbar characteristics having a constricted hysteresis loop. (2) Composition formula: (Fe_1_-_aM_a)_1_0_0_-_x_-
＿y＿−＿z＿−＿α＿−＿β＿−＿γA_xSi_y
B_zM'_αM”_βX_γ(at%) (However, M is Co and/or Ni, A is Cu,
At least one element selected from Ag and Au; M' is at least one element selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti, V, Mn, Cr and Mo;
M” is Al, platinum group element, Sc, Y, Zn, Sn, Re
at least one element selected from the group consisting of, X is C
, Ge, P, Ga, Sb, In, Be, As, at least one element selected from the group consisting of a, x, y
, z, α, β and γ are 0≦a≦0.5, 0.1, respectively
≦x≦3, 0≦y≦30, 0≦z≦25, 5≦y+z≦
30, 0.1≦α≦30, 0≦β≦10, 0≦γ≦10
satisfy. ) The ultrafine-crystalline magnetic alloy according to claim 1, wherein the ultrafine-crystalline magnetic alloy has a composition represented by: (3) The ultrafine-crystalline magnetic alloy according to claim 1, wherein the remainder of the structure is amorphous. (4) The ultrafine-crystalline magnetic alloy according to any one of claims 1 to 2, characterized in that it is substantially crystalline. (5) A process of manufacturing an amorphous alloy having the above composition, a process of heating the amorphous alloy so that at least 50% of the structure becomes fine crystals with an average grain size of 1000 Å or less, and bccFe formed by crystallization. A method for producing an ultrafine-crystalline alloy having perminver properties with a relatively constant magnetic permeability and a constricted hysteresis loop in a low excitation magnetic field, the method comprising the step of heat treatment at a temperature below the Curie temperature of a solid solution phase. (6) The method for producing an ultrafine-crystalline magnetic alloy according to claim 5, characterized in that the heat treatment at a temperature below the Curie temperature is carried out at 300° C. or above for 4 hours or more.