JP3500062B2 - Fe-based amorphous alloy ribbon with ultra-thin oxide layer - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a power transformer,
The present invention relates to an Fe-based amorphous alloy ribbon used for an iron core material such as a high frequency transformer.

[0002]

Amorphous alloy ribbons are obtained by quenching an alloy from its molten state. Known methods for producing a ribbon include a centrifugal quenching method, a single roll method, a twin roll method, and the like. In these methods, molten metal is jetted from an orifice or the like onto an inner peripheral surface or an outer peripheral surface of a metal drum rotating at high speed to rapidly solidify the molten metal to produce a ribbon or a wire. Further, by properly selecting the alloy composition, an amorphous alloy ribbon having excellent magnetic properties, mechanical properties, or corrosion resistance can be obtained.

The amorphous alloy ribbon is regarded as a promising industrial material in many applications because of its excellent properties. Among them, Fe-based amorphous alloy ribbons, such as Fe, are used for iron core materials such as power transformers and high-frequency transformers because of their low iron loss, high saturation magnetic flux density and high magnetic permeability. -Si-B system etc. are adopted.

The most widely disclosed for the purpose of improving the magnetic properties of the iron core material is an amorphous alloy ribbon having an insulating coating. The insulating coating has the effect of enhancing the insulating property between layers and reducing the eddy current loss caused by the crossover magnetic flux in a transformer core made by winding or laminating amorphous alloy ribbons. Conventionally, the followings have been disclosed for the purpose of improving the interlayer insulating property of the Fe-based amorphous alloy ribbon used for the iron core material. In the heat treatment process of the ribbon, oxygen of 20% or less is introduced and the surface of the ribbon is several tens to 100.
A method of improving the magnetic permeability by increasing the insulating property between layers when a toroidal core is formed by attaching an oxide film of nm (JP-A-6-346219).
However, the oxide layer is too thick with this method,
Cannot sufficiently improve iron loss.

On the other hand, the followings have been disclosed for the purpose of applying stress to the ribbon to improve iron loss and the like. A method of performing heat treatment in a mixed atmosphere of an inert gas and oxygen in order to form an oxide film layer having a thickness of 20 to 300 nm on the surface of the ribbon in order to apply a compressive stress in the in-plane direction of the ribbon (JP-A-61- 250162), but this method does not sufficiently improve iron loss because the oxide layer is too thick.

Regarding the oxide on the surface of the ribbon aimed at other effects, the followings have been disclosed. When annealing an iron-based amorphous alloy ribbon with an alumina insulating film obtained by baking an aqueous treatment liquid containing colloidal alumina hydrate as a main component, oxygen was introduced into the annealing atmosphere to oxidize Si on the ribbon surface. A method for preventing the oxidation of B by forming a film and preventing the crystallization of the ribbon surface (Japanese Patent Laid-Open No. 2-4913), and Ti, Zr, C having a thickness of 10 nm to 3.7 μm by vapor deposition.
There is a method of improving the wear resistance by forming an oxide of r, Al, Si or a nitride of Al, Si on the surface of an amorphous material (Japanese Patent Laid-Open No. 59-150081).

[0007]

As described above, as a conventional technique, there is a ribbon having an oxide layer formed on the surface of the ribbon for the purpose of improving iron loss of the ribbon, but it is possible to control the thickness of the oxide layer. It is not sufficient and the iron loss has not been sufficiently improved. Furthermore, in the prior art, in order to form an oxide layer, complicated surface treatment etc. are required.

According to the present invention, a low iron loss Fe-based amorphous alloy ribbon having an ultrathin oxide layer with a controlled thickness, or at least one of P and S under the ultrathin oxide layer with a controlled thickness is provided. It is an object of the present invention to provide a low iron loss Fe-based amorphous alloy ribbon having a segregation layer containing Fe.

[0009]

The gist of the present invention is as follows. (1) In a quenched metal ribbon obtained by jetting molten metal onto a moving cooling substrate through a pouring nozzle having a slot-shaped opening and rapidly cooling and solidifying the molten metal, the composition of the ribbon is F
a _{e a Si b B c C d} , 0.0003% or more by weight%
Wherein at least one of 0.1% or less of P or S, have at least the thickness of 5nm or more 20nm or less on one side of the ribbon surface ultrathin oxide layer, contact P further the bottom of the oxide layer
Containing at least one of S and S and having a thickness of 0.2 nm or more
Fe-based amorphous alloy ribbon according to claim Rukoto that having a segregation layer. However, a, b, c and d are atomic%, 70 ≦ a ≦ 86, 1 ≦ b ≦ 19, 7 ≦ c ≦ 20, 0.0
2 ≦ d ≦ 4 and a + b + c + d = 100 .

[0010] (2) above, characterized in that it has an ultra-thin oxide layer on the ribbon surface on the side not in contact with at least the cooling substrate
The Fe-based amorphous alloy ribbon according to item (1) .

(3) The ultra-thin oxide layer is a Fe-based oxide , Si
System oxide, B-based oxide or above, characterized in that is composed of a complex thereof (1) or (2) Fe-based amorphous alloy ribbon according.

(4) The thickness of the ribbon is 10 μm or more and 100
The above (1), (2) or (2) characterized in that
Alternatively, the Fe-based amorphous alloy ribbon according to (3) .

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
A feature of the present invention is that a Fe-based amorphous alloy ribbon having an ultrathin oxide layer having a controlled thickness, or at least one of P and S is provided below the ultrathin oxide layer having a controlled thickness. A low iron loss can be obtained by the amorphous alloy ribbon having the segregation layer containing.

During the process of casting the amorphous alloy ribbon in the atmosphere, an oxide layer is formed on the surface of the ribbon. The thickness of this oxide layer changes depending on the temperature of the ribbon and the atmosphere near the ribbon. The present inventors have found that an extremely thin oxide layer on the surface of the ribbon affects the iron loss. 1 (a), (b)
2 (a) and 2 (b) show Fe-Si-B-C (P,
S) system, the core loss and SEM of the ribbon when the ultrathin oxide layer thickness was controlled by changing the stripping temperature and the oxygen concentration in the atmosphere.
The magnetic domains taken by the method are shown. 1A shows the case where the ultrathin oxide layer has a thickness of 5.8 nm, FIG. 1B shows the case where the ultrathin oxide layer has a thickness of 7.0 nm, and FIG. In the case of 3 nm, FIG. 2B is a diagram showing the state of the magnetic domains when the ultrathin oxide layer thickness is 9.0 nm. From FIGS. 1A and 1B and FIGS. 2A and 2B, it can be seen that the magnetic domain is subdivided and the iron loss is reduced as the thickness of the oxide layer is increased.

Further, the inventors of the present invention have Fe--Si--B--C system and Fe--Si--B--C having various ultrathin oxide layer thicknesses.
The relationship between the thickness of the ultra-thin oxide layer of the (P, S) -based amorphous alloy ribbon and the hysteresis loss and eddy current loss obtained by iron loss separation was investigated. Among them, the present inventors have found that when the Fe-based amorphous ribbon has a three-layer structure having a segregation layer containing at least one of P and S between the ultrathin oxide layer and the amorphous layer, the ultrathin oxidation is observed. It was newly found that lower iron loss can be obtained than in the case of only the layer. FIG. 3 shows the result. Regarding the Fe-Si-B-C (P, S) system, the results when P and S are included are shown. In the case of the Fe-Si-BC system, the iron loss decreases as the thickness of the ultrathin oxide layer increases. In addition, the hysteresis loss also decreases as the thickness of the ultrathin oxide layer increases. However, the eddy current loss remains almost unchanged. On the other hand, Fe-Si-BC
In the case of the (P, S) system, the iron loss decreases with an increase in the thickness of the ultrathin oxide layer, but it shows a lower iron loss than in the case of the Fe-Si-B-C system. In addition, the hysteresis loss decreases with the increase of the ultrathin oxide layer thickness,
It is further reduced as compared with the case of the Fe-Si-BC system. This reduction in hysteresis loss is achieved by forming a segregation layer containing at least one of P and S between the amorphous layer and the ultrathin oxide layer, thereby smoothing the interface between them.
It is presumed that this is due to the result of facilitating the movement of the domain wall.
Further, in the case of the Fe-Si-B-C (P, S) system, the eddy current loss tends to decrease as the ultrathin oxide layer thickness increases. This tendency is in good agreement with the above-mentioned magnetic domain observation result.

The present inventors have found that Fe--Si having various thicknesses
-B-C system, Fe-Si-B-C (P, S) system ultra-thin oxide layer of the amorphous alloy ribbon and at least P and S between the ultra-thin oxide layer and the amorphous layer. The relationship between the thickness and the iron loss of the segregation layer containing one kind was investigated in more detail. As a result, the effect of reducing iron loss was confirmed when the thickness of the ultrathin oxide layer was in the range of 5 nm to 20 nm. 20 ultra-thin oxide layers
Even if the thickness was thicker than nm, the effect of further reducing iron loss was not observed. Therefore, the thickness of the ultrathin oxide layer is set to 20 nm or less. Further, when the thickness of the ultrathin oxide layer was less than 5 nm, the effect of reducing iron loss was not recognized. This is considered to be because when the thickness of the ultrathin oxide layer is less than 5 nm, it becomes difficult to form a uniform ultrathin oxide layer on the surface of the ribbon, and the magnetic domain is not subdivided. Therefore, the thickness of the ultrathin oxide layer is 5
It was set to nm or more. The mechanism of domain fragmentation is presumed to be due to the tension effect generated by the ultrathin oxide layer. The thickness of the ultra-thin oxide layer that can obtain more favorable iron loss is 8 nm or more and 14 n
m is less than or equal to 0.10 W / kg at W13 / 50
The following iron loss is obtained. Further, the segregation layer containing at least one of P and S also had no effect of reducing iron loss when the thickness was less than 0.2 nm. Therefore, the thickness of the segregation layer containing at least one of P and S is 0.2 nm or more. Is necessary. The thickness of these segregation layers is from 0.2 nm to 15
About nm is preferable. Even if the thickness exceeds 15 nm, the effect of reducing iron loss cannot be expected so much. In the case of a thin ribbon having a three-layer structure having a segregation layer containing at least one of P and S, an iron loss reducing effect is observed up to a thickness of the ultrathin oxide layer of about 100 nm.

The ultrathin oxide layer does not necessarily need to be present on both sides of the ribbon, and if it exists on at least one of the sides of the ribbon, the effect of reducing iron loss can be obtained. However, since it is easy to control the ultra-thin oxide layer during manufacturing, and the surface that contacts the cooling substrate has air pockets, it is difficult to make the ultra-thin oxide layer uniform. It is desirable to have layers.

In the present invention, the preferred strip thickness is 10 μm.
It is 100 μm or less. If the plate thickness is less than 10 μm,
This is because it is difficult to manufacture ribbons in a stable manner.
This is because it is difficult to stably manufacture the ribbon even when the plate thickness exceeds 100 μm, and the ribbon becomes brittle.
More preferably, a plate thickness of 10 μm or more and 70 μm or less is preferable because the casting of the ribbon becomes more stable. The thin strip width is not particularly limited, but is preferably 20 mm or more.

The set formed of a thin strip of the present invention, Fe _a Si _{b B c}
C _d , where a, b, c and d are atomic% and 70 ≦
a ≦ 86, 1 ≦ b ≦ 19, 7 ≦ c ≦ 20, 0.02 ≦ d
≦ 4, a + b + c + d = 100, or at least 0.0003% to 0.1% by weight of at least one of P and S in the above composition. More preferably, P
Is 0.003% to 0.1% by weight, and S is 0.0
It is 003% or more and 0.01% or less. When the thin ribbon is used for the iron core, the saturation magnetic flux density of the iron core needs to be a high value of 1.5 T or more. For that purpose, the content of Fe must be 70 atomic% or more. On the other hand, if the Fe content exceeds 86 atom%, it becomes difficult to form an amorphous material, and good ribbon characteristics cannot be obtained. Therefore, Fe is set to 70 atomic% or more and 86 atomic% or less.

Si and B are for improving amorphous forming ability and thermal stability. If Si is less than 1 atomic% and B is less than 7 atomic%, amorphous is not stably formed. On the other hand, if Si is more than 19 atomic% and B is more than 20 atomic%, the raw material cost is high. No improvement in amorphous forming ability and thermal stability is observed. Therefore, Si is 1 atom% or more and 19 atom% or less, B is 7 atom% or more and 20 atom% or more.
The following are preferred. C is an element effective in improving the castability of the ribbon. By containing C, the wettability of the molten metal and the cooling substrate is improved, and a good ribbon can be formed. If it is less than 0.02 atomic%, this effect cannot be obtained. Further, even if C exceeds 4 atom%, the improvement of this effect is not recognized. Therefore, C is set to 0.02 atomic% or more and 4 atomic% or less. To further stabilize the magnetic characteristics, Fe is added to 77
It is preferable that the atomic percentage is 83 atomic% or more and 83 atomic% or less, the Si content is 2 atomic% or more and 9 atomic% or less, and the B content is 11 atomic% or more and 17 atomic% or less.

Preferred ultra-thin oxide layers are Fe-based, Si-based,
It is a B-based oxide or an ultrathin composite oxide thereof. It is considered that these ultrathin oxides produce optimum tension on the amorphous alloy ribbon by being formed on the ribbon surface at a temperature higher than room temperature. Of these, Fe-based and Si-based oxides are more preferable. The ribbon of the present invention is, for example, Fe _80.5 Si _6.5 B ₁₂ C ₁ (atomic%) or Fe _80.5 Si _2.5 B ₁₆ C ₁ (atomic%) alloy with 0.05% by weight of P added. The molten metal can be manufactured by controlling the oxygen concentration in the chamber using a single roll device having a chamber whose atmosphere can be controlled. Similarly, it can be manufactured by a twin roll device having a chamber whose atmosphere can be controlled, a centrifugal quenching device using the inner wall of the drum, and a device using an endless type belt. It can also be manufactured by a method of strictly controlling the strip thickness and the peeling temperature with an atmospheric casting apparatus, or by controlling the atmosphere near the nozzle.

The thickness of the ultrathin oxide layer can be quickly measured by a surface analysis method using GDS (glow discharge emission spectroscopy), for example.

[0023]

The present invention will be further described based on the following examples. (Example 1) The base material has an alloy composition of atomic% of Fe _80.5 Si
_A mixture of _2.5 B ₁₆ C and ₁ atom% was used. This mother alloy has an outer diameter of 300
Using a single roll device having a Cu cooling roll of mm, the oxygen concentration in the chamber was changed little by little to produce ribbons having various ultrathin oxide layer thicknesses. The width of the ribbon is 25m
m. The thickness of the ultrathin oxide layer was determined from the concentration profile of each element obtained by GDS (glow discharge emission spectroscopy, sputtering rate 50 nm / sec). FIG. 4 shows an example thereof. Since Fe, Si, and B peaks are observed at positions overlapping with the oxygen peak, it can be seen that the oxide layer is an ultrathin oxide layer containing Fe-based, Si-based, and B-based oxides.

After these ribbons were annealed at 360 ° C. for 1 hour in a nitrogen atmosphere in a magnetic field, SST (Single S
The iron loss was measured by a trip tester). The thickness of the ultra-thin oxide layer was almost unchanged before and after annealing. The results are shown in Table 1. As shown in Table 1, the thickness of the ultrathin oxide layer is 5n.
If it is less than m, the iron loss of W13 / 50 is 0.135 W / kg or more, but at least any one of the ultrathin oxide layers on the surface of the ribbon exceeds 5 nm and the iron loss increases as the ultrathin oxide layer becomes thicker. The core loss decreases to about 0.10 W / kg in the vicinity of 10 nm. However, as the thickness of the ultra-thin oxide layer further increases, the iron loss increases, and when the thickness exceeds 20 nm, the iron loss becomes 0.135
Iron loss of W / kg or more. As you can see from this result,
It is clear that an ultrathin oxide layer having a thickness of 5 nm or more and 20 nm or less has an effect of reducing iron loss.

In addition, No. 1 shown in Table 1 2-a is N
o. The free surface of the ribbon 2 was masked and then etched to remove the ultrathin oxide layer on the roll surface.
No. 2-b is No. The roll surface of the thin ribbon of No. 2 was masked to remove the ultrathin oxide layer on the free surface. N
o. 2, No. 2-a and No. The iron loss of 2-b is almost unchanged.

[0026]

[Table 1]

Example 2 The alloy composition used in Example 1 is Fe _80.5 Si _2.5 B ₁₆ C ₁
0.01 to 0.05 wt% in the base material blended to atomic%
In the same manner as in Example 1, P was added in the range of P and 0.007% by weight of S, either alone or in combination, to produce a ribbon. The thickness of the segregation layer was changed by changing the amount of P and the cooling rate of the ribbon. FIG. 5 shows an example in which P and S are added together in the concentration profile of each element of GDS of the obtained ribbon. This Figure 5
Is different from the profile of FIG. 4, P and S peaks are observed on the right side of the oxygen peak (inward direction of the ribbon).
This fact means that there is a P and S segregation layer between the ultrathin oxide layer and the amorphous layer, and the layer has a three-layer structure. Further, since peaks of Fe, Si, and B are observed at positions overlapping with the oxygen peak, it can be seen that the oxide layer is an extremely thin oxide layer containing Fe-based, Si-based, and B-based oxides.

These ribbons were heat treated in the same manner as in Example 1 and the iron loss was measured by SST. The results are shown in Table 2. P,
When the thickness of the S segregation layer is less than 0.2 nm, the iron loss of W13 / 50 is 0.135 W / kg or more, but the iron loss decreases as the P, S segregation layer becomes thicker than 0.2 nm. 0.10 W / kg when the thickness of the segregation layer is in the range of 4 to 12 nm
The following low iron loss is shown. After that, the iron loss increases as the thickness of the segregation layer increases, but 0.135 W / kg up to about 15 nm.
The following iron loss is shown. At this time, the thickness of the ultra-thin oxide layer is 26n.
It can be seen that the range of the thickness of the ultrathin oxide layer exhibiting low iron loss is wider than that in the case of only the ultrathin oxide layer.

As described above, in the thin ribbon having a three-layer structure having the P and S segregation layers between the ultrathin oxide layer and the amorphous layer, the P and S segregation layers having a thickness of 0.2 nm or more are iron. It is clear that it has the effect of reducing loss. In addition, Example 1
Similarly, No. 1 in Table 2 No. 25-a is No. The free surface of the thin strip of No. 25 was masked and then etched to remove the ultrathin oxide layer and the P and S segregation layers on the roll surface. No. 25-b is No. The roll surface of 25 ribbon was masked to remove the ultrathin oxide layer and the P and S segregation layers on the free surface. As can be seen from the results in Table 2,
No. 25, no. 25-a and No. The iron loss of 25-b shows almost no change, and it is understood that the ultrathin oxide layer and the P and S segregation layers should be on at least one surface of the ribbon.

[0030]

[Table 2]

(Example 3) Using the base material used in Examples 1 and 2, a single roll apparatus having a Cu cooling roll having an outer diameter of 600 mm was used to produce a ribbon in the atmosphere. . Thin strips of various thicknesses were produced using nozzles with single and multiple slits. During the production, the peeling position of the ribbon was changed and the peeling temperature of the ribbon was changed to control the thickness of the ultrathin oxide layer. The strip width was 25 mm. The thickness of the ultrathin oxide layer and the P and S segregation layers of the obtained ribbon was measured by GDS.
I researched in. Moreover, from the result of GDS, the ultrathin oxide layer was Fe.
It was an oxide layer containing a system-based, Si-based, and B-based oxide. The obtained ribbon was heat treated in the same manner as in Example 1 and Example 2,
The iron loss was measured by SST. The results are shown in Table 3. As shown in Table 3, it was found that a low iron loss with W13 / 50 of 0.135 W / kg or less was obtained in a wide plate thickness range of 10 μm to 100 μm, and N produced for comparison was used.
o. The 41 ribbon has an innumerable number of holes throughout the ribbon, and N
o. The thin ribbon of 51 was brittle, and stable production was difficult.

[0032]

[Table 3]

[0033]

As described above, the low iron loss Fe-based amorphous alloy ribbon having the ultrathin oxide layer of the present invention, or P and S in the lower portion of the ultrathin oxide layer having a controlled thickness. The low iron loss Fe-based amorphous alloy ribbon having the segregation layer containing at least one kind improves the characteristic variation of the low iron loss ribbon and facilitates stable production.

[Brief description of drawings]

FIG. 1 is a magnetic domain observation photograph of a ribbon, (a) shows the case where the ultrathin oxide layer thickness is 5.8 nm, and W13 / 50 is 0.12.
A magnetic domain observation photograph at 7 W / kg and a magnetic domain width of 1.7 mm, (b) is a case where the ultrathin oxide layer thickness is 7.0 nm,
W13 / 50 is 0.097 W / kg, magnetic domain width is 1.3 m
It is a magnetic domain observation photograph in case of m.

FIG. 2 is a magnetic domain observation photograph of a ribbon, (a) shows the case where the ultrathin oxide layer thickness is 8.3 nm, and W13 / 50 is 0.08.
A magnetic domain observation photograph at 0 W / kg and a magnetic domain width of 0.8 mm, (b) is a case where the ultrathin oxide layer thickness is 9.0 nm,
W13 / 50 is 0.077 W / kg, magnetic domain width is 0.5 m
It is a magnetic domain observation photograph in case of m.

FIG. 3 is a diagram showing the relationship between the thickness of an ultrathin oxide layer and iron loss.

FIG. 4 is a diagram showing an example of an element concentration profile by GDS (glow discharge emission spectroscopy).

FIG. 5 is a diagram showing an example of an element concentration profile of GDS of an amorphous alloy ribbon produced by adding P and S to a mother alloy.

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-2-194503 (JP, A) JP-A-61-250162 (JP, A) JP-A-9-95760 (JP, A) JP-A-9- 202946 (JP, A) JP 8-283919 (JP, A) JP 6-100999 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B22D 11/06 360 C22C 45/02 C23C 8/14 H01F 1/153

Claims (4)

(57) [Claims] To 1. A mobile cooling substrate, spewing molten metal through a pouring nozzle having a slot-like opening, in quenched metal strip obtained by rapid solidification, the ribbon set
Fe _a Si _b B _c C _d is 0.0003% by weight.
% Or more and 0.1% or less of at least one P or S
The thickness of at least one side of the ribbon is 5 nm or more 20
nm have a following ultrathin oxide layer, the bottom of the further oxide layer
A thickness of 0.2 nm containing at least one of P and S
Fe-based amorphous alloy ribbon according to claim Rukoto to have a more segregation layer. However, a, b, c and d are atomic%, 70 ≦ a ≦ 86, 1 ≦ b ≦ 19, 7 ≦ c ≦ 20, 0.0
2 ≦ d ≦ 4 and a + b + c + d = 100 . 2. A method according to claim 1, characterized in that it comprises an ultra-thin oxide layer on the ribbon surface on the side not in contact with at least the cooling substrate
The Fe-based amorphous alloy ribbon described. 3. The ultra-thin oxide layer is a Fe-based oxide or a Si-based oxide.
The Fe-based amorphous alloy ribbon according to claim 1 or 2, wherein the ribbon is composed of a substance , a B-based oxide, or a composite thereof. 4. The Fe-based amorphous alloy ribbon according to claim 1, 2 or 3, wherein the ribbon has a plate thickness of 10 μm or more and 100 μm or less.