KR20140101595A - Soft magnetic amorphous material ally and preparation method thereof - Google Patents

Abstract

The present invention relates to a soft magnetic amorphous alloy and a method for manufacturing the same. The soft magnetic amorphous alloy is indicated by the structural formula 1, Fe_a C_b Si_c B_d P_e M_f. According to the present invention, the soft magnetic amorphous alloy has an effect of manufacturing powder, and having high amorphous forming ability and high saturated magnetic flux density, so the soft magnetic amorphous alloy can be widely applied to a transformer, a motor, a choco, an inductor magnetic core, etc. Moreover, the soft magnetic amorphous alloy has an effect of improving the coercive force by achieving nanocrystallization through the additional isothermal heat treatment and having excellent soft magnetic properties. In the structural formula 1, the M is at least one kind selected among a group consisting of Co, Ni, Cu, Ag, Zn, Hf, Y, Ga, Ge and Al, and a=100-(b+c+d+e+f), 5.0<=b<=7.0, 2.3<=c<=3.3, 2.5<=d<= 5.5, 6.7<=e<=8.7, and 0.1<=f<=5.0.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to soft magnetic amorphous alloys,

The present invention relates to a soft magnetic amorphous alloy and a method of manufacturing the same. More particularly, the present invention relates to a soft magnetic amorphous alloy having a high amorphous forming ability and a high saturation magnetic flux density.

An amorphous alloy is an alloy having an irregular atomic structure such as a liquid. When a metal melted in the course of making an alloy is quenched at a pace of 1 million degrees Celsius per second, the amorphous alloy becomes an amorphous alloy, And the alloy thus produced is referred to as an amorphous alloy.

Such an amorphous alloy has an excellent rigidity as compared with a general metal material because of the absence of a crystal structure even when observed up to a molecular unit, but has a problem of poor workability, that is, amorphous forming ability.

The soft magnetic property refers to a magnetic property having a small coercive force and residual magnetization and a high magnetic permeability in the hysteresis curve, and corresponds to the light hardness. This magnetism is magnetized only when magnetic force is applied, and when the external magnetic field is removed, magnetization is almost lost.

On the other hand, amorphous alloys are often used for soft magnetic materials having soft magnetic properties, because they have a short range order (SRO) without having a long range order (LRO), so that amorphous alloys It is widely used.

Due to these advantages, amorphous alloys are widely used in the manufacture of soft magnetic materials, whereas soft magnetic amorphous alloys have a relatively low amorphous ability to exhibit various applications thereof.

That is, amorphous alloys can be amorphized at a lower critical cooling rate than conventional amorphous alloys only if the amorphous forming ability is increased, and it is possible to manufacture amorphous amorphous alloys with a thickness of several mm depending on the alloys. In addition, it is also possible to produce amorphous powders directly by using a gas and water spray method having a relatively slow cooling rate only when the amorphous forming ability is increased. Although the amorphous formability must be increased to such a degree that the powder can be directly manufactured, the soft amorphous alloy can be widely used in commercial applications such as transformers, motors, chokes and inductor core.

However, although it is essential to increase the amorphous forming ability, it is problematic that the soft amorphous alloy has a low amorphous forming ability.

Therefore, although studies for overcoming the low amorphous forming ability in the production of soft magnetic amorphous alloys have been continuously carried out, the amorphous elements added so far in order to overcome the low amorphous forming ability have a problem of lowering the saturation magnetic flux density of the alloy, , Which is a problem that is a factor that hinders various applications of the soft magnetic amorphous alloy.

Therefore, the development of a soft magnetic amorphous alloy having a high amorphous forming ability and a good saturation magnetic flux density at the same time is urgently required, and related prior art documents are as follows.

Korean Patent Publication No. 10-2009-0079972 Korean Patent Publication No. 10-2007-0079575

It is an object of the present invention to provide a soft magnetic amorphous alloy having a saturation magnetic flux density superior to that of a conventional soft magnetic amorphous alloy and a method of manufacturing the same.

The present invention also provides a soft magnetic amorphous alloy having high amorphous forming ability as a factor indicating various applications of the soft magnetic amorphous alloy.

The present invention also provides a soft magnetic material having a high saturation magnetic flux density and various usability by reducing manufacturing cost by minimizing alloying elements while using low-cost cast iron as a main raw material.

The present invention provides a soft magnetic amorphous alloy having the following structural formula (1) for solving the above problems.

[Structural formula 1]

Fe _a C _b Si _c B _d P _e M _f

In the above formula 1,

Wherein M is at least one element selected from the group consisting of Co, Ni, Cu, Ag, Zn, Hf, Y, Ga,

b? 7.0, 2.3? c? 3.3, 2.5? d? 5.5, 6.7? e? 7.7, and 0.1? f? 5.0, where a = 100- (b + c + d + e + f).

The soft magnetic amorphous alloy has a saturation magnetic flux density of 1.10-1.40 T as measured by a vibrating sample magnetometer.

The soft magnetic amorphous alloy has a coercive force of 1-5 A / m as measured by a vibrating sample magnetometer.

The soft magnetic amorphous alloy has a critical thickness of 1.5 to 3.5 mm as measured by an X-ray diffraction method.

The soft magnetic amorphous alloy further comprises nanocrystals having a size of 2-30 nm.

The present invention also provides a method for producing a soft amorphous alloy, comprising the steps of:

(a) melting a metal element represented by Fe _a C _b Si _c B _d P _e M _f while heating at a temperature of 1,000-1,500 ° C to produce a parent alloy,

(b) cooling and amorphizing the molten alloy in the molten state while injecting an inert gas at 20-30 ° C,

(c) confirming the Tg (glass transition temperature) of the parent alloy after the amorphization by the step (b), and

(d) After confirming Tg (占 폚) by the step (c), the Tg is increased to -50 to -20 占 폚 at a heating rate of 35-45 占 폚 / min, Forming a crystal of size.

Wherein M is at least one selected from the group consisting of Co, Ni, Cu, Ag, Zn, Hf, Y, Ga, Ge and Al, a = 100- (b + c + B? 7.0, 2.3? C? 3.3, 2.5? D? 5.5, 6.7? E? 8.7 and 0.1? F? 5.0.

The soft magnetic amorphous alloy according to the present invention can be widely used for transformers, motors, chokes and inductor cores because of its high amorphous forming ability and high saturation magnetic flux density.

Further, it is possible to provide a soft magnetic amorphous alloy which achieves nanocrystallization through additional isothermal heat treatment to improve coercive force, thereby exhibiting excellent soft magnetic characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a single-roll rapid cooling apparatus used in an embodiment of the present invention. FIG.
2 is a photograph showing that some nanocrystals are formed in the alloy of Example 1 according to the present invention.
3 is a photograph showing that some nanocrystals are formed in the alloy of Example 6 according to the present invention.
4 is a schematic view of a water-cooled casting apparatus used for measuring a critical thickness in an experimental example of the present invention.
5 is a graph showing a magnetic hysteresis curve for the alloy of Example 3 according to the present invention.
6 is a graph showing the critical thickness measured for the alloy of Example 1 of the present invention.
7 is a graph showing a magnetic hysteresis curve for the alloy of Example 4 of the present invention.
8 is an XRD graph showing the formation of nanocrystals in an amorphous alloy according to Example 12 of the present invention.

The present inventors have made extensive efforts to develop soft magnetic amorphous alloys having excellent saturation magnetic flux density and high amorphous forming ability and at the same time increasing coercive force and having excellent soft magnetic characteristics. As a result, the soft magnetic amorphous alloy according to the present invention and its production method .

Specifically, the soft magnetic amorphous alloy according to the present invention is characterized by being represented by the following structural formula (1).

[Structural formula 1]

Fe _a C _b Si _c B _d P _e M _f

In the above formula 1,

Wherein M is at least one element selected from the group consisting of Co, Ni, Cu, Ag, Zn, Hf, Y, Ga,

b? 7.0, 2.3? c? 3.3, 2.5? d? 5.5, 6.7? e? 7.7, and 0.1? f? 5.0, where a = 100- (b + c + d + e + f).

The Fe is a key element in which the soft magnetic amorphous alloy according to the present invention corresponds to the Fe-based soft magnetic amorphous alloy, and when the a corresponds to the atomic percentage of 100- (b + c + d + e + f) It is possible to provide an Fe-based soft magnetic amorphous alloy having a high saturation magnetic flux density and excellent amorphous forming ability to be achieved in the present invention.

In addition, when C is less than 5.0 atomic percent, C can not form a complete amorphous alloy, and C is more than 7.0 atomic percent, contributing to the effect of the present invention. It is undesirable because there is a risk of limiting the content of the remaining substances.

In addition, Si is also a key element for forming amorphous. If c is less than 2.3 atomic%, it is not preferable because it can not form intact amorphous. If c exceeds 3.3 atomic%, it contributes to the effect of the present invention The content of the remaining substances may be limited.

The above-mentioned B is also a key element for forming amorphous. When d is less than 2.5 atomic%, it is not possible to form intact amorphous, and when d exceeds 5.5 atomic%, it contributes to the effect of the present invention It is undesirable because there is a risk of limiting the content of the remaining substances.

P is also a key element for forming amorphous. When e is less than 6.7 at%, it is not preferable because it can not form intact amorphous. When e is more than 8.7 at%, P contributes to the effect of the present invention It is undesirable because there is a risk of limiting the content of the remaining substances.

The M is a core element that prevents a sharp reduction in the saturation magnetic flux density and enables the formation of a high amorphous forming ability. The M is a rare earth element such as Co, Ni, Cu, Ag, Zn, Hf, Al. Of these, Co and Ni correspond to ferromagnetic elements.

If f is less than 0.1 atomic%, it is not preferable to exhibit high amorphous forming ability and prevent sudden decrease in saturation magnetic flux density. If f is more than 5.0 atomic%, the content of the remaining material is limited It is not preferable because amorphous is difficult to be formed completely.

When M is Ni, it is preferable that f is 0.1-3 atomic%. At this time, if the Ni content exceeds 3 atomic%, the saturation magnetic flux density is reduced to less than 1 T, and the content of the remaining material contributing to the effect of the present invention is limited.

When the content of Ni is 0.1-3 atomic%, the content of the remaining material except Fe in the composition of the soft magnetic amorphous alloy according to the present invention does not change, Lt; / = f &lt; / = 5.0.

When M is at least one selected from the group consisting of Cu, Hf and Al, it is preferable that f is 0.1 to 2 atomic%. At this time, when at least one selected from the group consisting of Cu, Hf and Al is more than 2 atomic%, a crystal phase corresponding to an impurity is formed or the saturation magnetic flux density is decreased to 1 T or less, which is not preferable. Particularly, when Cu is more than 2 atomic%, impurities are formed by forming Fcc-Cu and Fe2P phases in the amorphous state, which is not preferable.

When the content of at least one selected from the group consisting of Cu, Hf and Al is 0.1 to 2 atomic%, the content of the remaining material except for Fe in the composition of the soft magnetic amorphous alloy according to the present invention is more preferably changed , But the remaining M may be added in the range of 0.1? F? 5.0.

The soft magnetic amorphous alloy according to the present invention can provide a soft amorphous alloy having a high amorphous forming ability and a high saturation magnetic flux density to be achieved in the present invention when the soft magnetic amorphous alloy according to the present invention has a total composition of the atomic%.

The soft magnetic amorphous alloy can be a soft magnetic amorphous alloy having Fe and C constituting cast iron (Fe-C), which are low-cost raw materials, and the remaining Si, B, P and M as minor alloying have. Therefore, the present invention can be applied to an Fe-based soft magnetic amorphous alloy.

The soft magnetic amorphous alloy according to the present invention is characterized in that the saturation magnetic flux density measured by a vibrating sample magnetometer is 1.10-1.40 T and the coercive force measured by a vibration sample magnetometer is 1-5 A / m. The soft magnetic amorphous alloy has a critical thickness of 1.5 to 3.5 mm as measured by an X-ray diffraction method.

Therefore, the soft magnetic amorphous alloy according to the present invention can be a soft magnetic amorphous alloy having the saturation magnetic flux density measured in the above range and having excellent saturation magnetic flux density, and the critical thickness can be variously used for the soft magnetic amorphous alloy And the critical thickness is measured in the above range to correspond to a soft magnetic amorphous alloy having high amorphous forming ability.

The soft magnetic amorphous alloy may further include nanocrystals having a size of 2 to 30 nm. Since the nanocrystals are further included, the coercive force is greatly reduced and the soft magnetic properties of the soft magnetic amorphous alloy can be further improved . When the soft magnetic amorphous alloy has a size of less than 2 nm, the effect of improving the soft magnetic properties is not sufficient, and when the size of the soft magnetic amorphous alloy exceeds 30 nm, the nanocrystalline It is not preferable.

As a result, the soft magnetic amorphous alloy represented by Fe _a C _b Si _c B _d P _e M _f according to the present invention further comprises M in the soft magnetic amorphous alloy represented by Fe _a C _b Si _c B _d P _e Soft amorphous alloy is a soft magnetic amorphous alloy capable of exhibiting a high amorphous forming ability while preventing a sharp decrease in the high saturation magnetic flux density possessed by Fe _a C _b Si _c B _d P _e .

Further, another aspect of the present invention relates to a method for producing a soft magnetic amorphous alloy, which comprises the following steps.

(a) melting a metal element represented by Fe _a C _b Si _c B _d P _e M _f while heating at a temperature of 1,000-1,500 ° C to produce a parent alloy,

(b) cooling and amorphizing the molten alloy in the molten state while injecting an inert gas at 20-30 ° C,

(c) confirming the Tg (glass transition temperature) of the parent alloy after the amorphization by the step (b), and

(d) After confirming Tg (占 폚) by the step (c), the Tg is increased to -50 to -20 占 폚 at a heating rate of 35-45 占 폚 / min, Forming a crystal of size.

Wherein M is at least one selected from the group consisting of Co, Ni, Cu, Ag, Zn, Hf, Y, Ga, Ge and Al, a = 100- (b + c + B? 7.0, 2.3? C? 3.3, 2.5? D? 5.5, 6.7? E? 8.7 and 0.1? F? 5.0.

The inert gas injected in the step (b) is injected to cool the molten parent alloy in a stable state without being denatured. Preferably, the inert gas is one selected from the group consisting of helium, neon, argon, krypton, xenon and radon More than one species of inert gas may be used.

The Tg (glass transition temperature) determined in the step (c) is a temperature at which the gradient of the center of gravity of the amorphous solid changes from a loose state such as glass to a viscous state, And the temperature to be heated in the step (d) is determined through the Tg determined in the step (c).

If the heating rate is less than 5 ° C / min, the time for temperature increase is excessively long, and the crystal is too large. In this case, If the temperature raising rate exceeds 45 ° C / min, it is impossible to form a sufficient crystal due to a rapid heating rate and the soft magnetic state may not be improved. I do not.

In the step (d), the temperature is preferably raised from the Tg (° C) -50 to the Tg (° C) -20 ° C. When the temperature is raised to below Tg (° C) It is not preferable to form sufficient crystals that contribute to the effect of the invention, and when the temperature is raised above Tg (占 폚) -20 占 폚, the crystal size may become large enough to cause amorphousness.

The size of the crystals formed in the step (d) is preferably 2 to 30 nm. When the size of the crystals is less than 2 nm, the effect of the crystals contributing to the present invention is weak, When the size of the crystal is more than 30 nm, the effect of nanocrystallization to be achieved in the present invention may be deteriorated.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Example

The parent alloys corresponding to Fe _a C _b Si _c B _d P _e M _f were prepared by vacuum arc melting method. At this time, the mother alloy was produced by melting at 1,200 ° C. After that, it was quenched at room temperature while argon (Ar) was injected by using a monolith rapid cooling apparatus which was manufactured again. Through this quenching process, amorphization is achieved.

Then, the Tg (glass transition temperature, glass transition temperature, ° C.) of the parent alloy was confirmed using a differential scanning calorimeter (DSC, Perkin Elmer Diamond, USA). The temperature was raised at a rate of 40 ° C / minute to the temperature corresponding to Tg-35 ° C thus confirmed. After the temperature was raised, the heat treatment was performed, and a soft magnetic amorphous alloy ribbon was produced. In this case, the _{Fe a C b Si c B d} P e instead of the soft magnetic amorphous alloy for the _{Fe a C b Si c B d} P e M _f was prepared in the. At this time, the M may include at least one selected from the group consisting of Co, Ni, Cu, Hf, and Al.

The composition of the soft magnetic amorphous alloy, Fe _a C _b Si _c B _d P _e M _f , with respect to the atomic% is as follows: a = 100- (b + c + d + e + f) 2.5, d? 5.5, 6.7? E? 7.7, and 0.1? F? 5.0, and the ribbon of the soft magnetic amorphous alloy was fabricated with twelve cases corresponding thereto. The weight of the ribbon made of each alloy was 20 g. Each of them was named Examples 1 to 12, and the composition of each was shown in Table 1 below.

1 is a schematic view of the rapid cooling apparatus. FIG. 2 is a photograph showing that some nanocrystals are formed within a range that does not affect the amorphous state in Example 1. FIG. 3 is a photograph showing the formation of some nanocrystals within a range that does not affect the amorphous state in Example 6. FIG. .

Comparative Example

Comparative Example  One

A soft magnetic amorphous alloy was prepared using the same method as the above example. However, instead of Fe _a C _b Si _c B _d P _e M _f , a soft magnetic amorphous alloy corresponding to Fe _a C _b Si _c B _d P _e was prepared. Further, the composition regarding the atomic% of the soft magnetic amorphous alloy as Fe _a C _b Si _c B _d P _e is as follows: a = 100- (b + c + d + e), 5.0 b 7.0, , 2.5? D? 5.5 and 6.7? E? 8.7, and the ribbon of the soft magnetic amorphous alloy was manufactured with the two cases. The weight of the ribbon made of each alloy was 20 g. Each of them was named as Comparative Example 1-1 and Comparative Example 1-2, and the composition of each was shown in Table 2 below.

Comparative Example  2

A ribbon of a soft magnetic amorphous alloy was produced in the same manner as in Example 1, except that the composition was Fe ₇₄ Nb ₆ Y ₃ B _{17, which} is a composition of a soft magnetic amorphous bulk alloy as a soft magnetic amorphous alloy .

Comparative Example  3

As the soft magnetic amorphous alloy subjected to ensure that the composition of the soft magnetic amorphous alloy of the bulk composition of Fe _{65.7 C 7 .0 Si 3 .3 B 5.5} P 8 .7 Cr 2 .3 Mo 2 .5 Al 2 .0 C 3 A ribbon of a soft magnetic amorphous alloy was prepared using the same method as in Example 1 above.

Experimental Example

The experiments for measuring the saturation magnetic flux density, coercive force, critical thickness and constitutional phases of Examples 1 to 5, Comparative Example 1-1, Comparative Example 1-2, Comparative Example 2 and Comparative Example 3 were performed . The saturation magnetic flux density and coercive force were measured with a vibrating sample magnetometer (VSM-7407, Lakeshore Cryotronics, USA), and the critical thicknesses and constitutional phases were measured by X-ray diffraction (XRD). The critical thickness was measured after using a water-cooled casting apparatus before measurement by the X-ray diffraction method. The results are also shown in Table 3 below.

The saturation magnetic flux density in the results of Table 3 corresponds to a superior soft magnetic amorphous alloy as the measured value is higher, and as the measured value of coercive force is lower, it corresponds to a superior soft magnetic amorphous alloy.

In addition, the critical thickness is an index for confirming the superiority of the amorphous forming ability indicating various applications of the soft magnetic amorphous alloy, and corresponds to a soft magnetic amorphous alloy having an excellent amorphous forming ability as the critical thickness is thicker.

In addition, the above-mentioned constitution is amorphous. In the present invention, however, it is formed by heating after quenching according to the above embodiment, and may include crystals having a size of 2-30 nm in a range not affecting the amorphous state. 4 is a schematic view of a water-cooled casting apparatus used for measuring the critical thickness. 5 is a graph showing the magnetic hysteresis curve of the alloy of Example 3. Fig.

6 is a graph showing that the critical thickness of XRD measured according to Example 1 corresponds to 2.2 mm.

The saturation magnetic flux density corresponds to an excellent soft magnetic amorphous alloy that should be equal to or greater than 1 T, and in the case of Comparative Example 2 and Comparative Example 3, the saturation magnetic flux density is 1 T or less. As the soft magnetic amorphous alloy, And it was confirmed that the quality was low.

In the case of the comparative example 1-1 and the comparative example 1-2, the comparative example 2 and the comparative example 1 were compared with each other. In the comparative example 1-1 and the comparative example 1-2, the amorphous alloy exhibits excellent amorphous ability, 3, it can be confirmed that the amorphous forming ability is lower than that of Examples 1 to 12 because the critical thickness is 1 mm or less.

On the other hand, in the case of Examples 1 to 12, it was confirmed that the threshold thicknesses exceeded 1.5 mm and the amorphous forming ability was excellent.

Even though the saturation magnetic flux density was slightly lower in Examples 1 to 12 than Comparative Examples 1-1 and 1-2, the results were far superior to those of Comparative Examples 2 and 3, The soft magnetic amorphous alloy according to the present invention is a soft magnetic amorphous alloy exhibiting excellent saturation magnetic flux density and high amorphous forming ability.

Therefore, it was confirmed from the results of Experimental Example 1 that the soft magnetic amorphous alloy according to Examples 1 to 12 is a soft magnetic amorphous alloy having an excellent amorphous forming ability and a high saturation magnetic flux density as compared with the conventional bulk amorphous alloy .

Table 4 shows the results of isothermal annealing of alloys having compositions of Examples 1, 6, 9 and 12 at Tg-50 占 폚.

As shown in Table 4, when the isothermal annealing is performed under the above conditions, the saturation magnetic flux density is increased while forming nanocrystals, and the coercive force is greatly reduced, .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. It is natural.

Claims (6)

The soft magnetic amorphous alloy represented by the following structural formula 1:
[Structural formula 1]
Fe _a C _b Si _c B _d P _e M _f
M is at least one element selected from the group consisting of Co, Ni, Cu, Ag, Zn, Hf, Y, Ga,
b? 7.0, 2.3? c? 3.3, 2.5? d? 5.5, 6.7? e? 7.7, and 0.1? f? 5.0, where a = 100- (b + c + d + e + f).
The method according to claim 1,
Wherein the soft magnetic amorphous alloy has a saturation magnetic flux density of 1.10-1.40 T as measured by a vibrating sample magnetometer.
The method according to claim 1,
Wherein the soft magnetic amorphous alloy has a coercive force of 1-5 A / m as measured by a vibrating sample magnetometer.
The method according to claim 1,
Wherein the soft magnetic amorphous alloy has a critical thickness of 1.5-3.5 mm as measured by an X-ray diffraction method.
The method according to claim 1,
Wherein the soft magnetic amorphous alloy further comprises nanocrystals of 2-30 nm in size.
(a) melting a metal element represented by Fe _a C _b Si _c B _d P _e M _f while heating at 1,000-1,500 ° C to produce a parent alloy;
(b) cooling and amorphizing the molten alloy in the molten state while injecting an inert gas at 20-30 ° C;
(c) confirming a Tg (glass transition temperature) of the parent alloy after the amorphization by the step (b); And
(d) After confirming Tg (占 폚) by the step (c), the Tg is increased to -50 to -20 占 폚 at a heating rate of 35-45 占 폚 / min, Forming a crystal of a size,
Wherein M is at least one selected from the group consisting of Co, Ni, Cu, Ag, Zn, Hf, Y, Ga, Ge and Al, a = 100- (b + c + B? 7.0, 2.3? C? 3.3, 2.5? D? 5.5, 6.7? E? 8.7 and 0.1? F? 5.0.

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