JP6662438B2 - Soft magnetic alloys and magnetic components - Google Patents

Description

  The present invention relates to a soft magnetic alloy and a magnetic component.

  2. Description of the Related Art In recent years, low power consumption and high efficiency have been demanded for electronic, information, and communication devices. Furthermore, the above-mentioned demands are becoming stronger toward a low-carbon society. Therefore, power supply circuits for electronic, information, and communication devices are also required to reduce energy loss and improve power supply efficiency. The magnetic core of the porcelain element used in the power supply circuit is required to have an improved magnetic permeability and a reduced core loss (core loss). If the core loss is reduced, the power energy loss is reduced, and higher efficiency and energy saving are achieved.

  Patent Document 1 discloses a soft magnetic amorphous alloy of the Fe-BM (M = Ti, Zr, Hf, V, Nb, Ta, Mo, W) type. This soft magnetic amorphous alloy has good soft magnetic properties, such as having a higher saturation magnetic flux density than commercially available Fe amorphous.

Patent No. 3342767

  As a method of reducing the core loss of the magnetic core, it is conceivable to reduce the coercive force of the magnetic material constituting the magnetic core.

  An object of the present invention is to provide a soft magnetic alloy having a high saturation magnetic flux density Bs, a low coercive force Hc, and a high specific resistance ρ.

In order to achieve the above object, the soft magnetic alloy according to the present invention is:
A soft magnetic alloy containing Fe as a main component and P,
An Fe-rich phase and an Fe-poor phase,
The average concentration of P in the Fe-poor phase is 1.5 times or more in terms of the number of atoms with respect to the average concentration of P in the soft magnetic alloy.

  The soft magnetic alloy according to the present invention has the above characteristics, and thus has a high saturation magnetic flux density Bs, a low coercive force Hc, and a high specific resistance ρ.

  In the soft magnetic alloy according to the present invention, the average concentration of P in the Fe-poor phase may be 1.0 at% or more and 50 at% or less.

  In the soft magnetic alloy according to the present invention, the average concentration of P in the Fe-poor phase may be 3.0 times or more the average concentration of P in the Fe-rich phase.

Soft magnetic alloy according to the present invention is a soft magnetic alloy represented by a composition formula _{(Fe 1-α X α)} (1- (a + b + c + d + e)) Cu a M1 b P c M2 d Si e,
X is one or more selected from Co and Ni;
M1 is at least one selected from Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn, La, Y and S;
M2 is one or more selected from B and C;
0 ≦ a ≦ 0.030
0 ≦ b ≦ 0.150
0.001 ≦ c ≦ 0.150
0 ≦ d ≦ 0.200
0 ≦ e ≦ 0.200
0 ≦ α ≦ 0.500
It may be.

  The soft magnetic alloy according to the present invention may have Fe-based nanocrystals.

  In the soft magnetic alloy according to the present invention, the Fe-based nanocrystal may have an average particle size of 5 nm or more and 30 nm or less.

  The soft magnetic alloy according to the present invention may have a ribbon shape.

  The soft magnetic alloy according to the present invention may be in a powder form.

  A magnetic component according to the present invention is made of any of the soft magnetic alloys described above.

FIG. 1 shows the result of observing the distribution of Fe in the soft magnetic alloy of the present invention by 3DAP. FIG. 2 is a schematic diagram showing the result of observing the soft magnetic alloy of the present invention with 3DAP and binarizing it with the Fe content. FIG. 3 is a schematic diagram of the single roll method.

  Hereinafter, embodiments of the present invention will be described.

  The soft magnetic alloy according to the present embodiment is a soft magnetic alloy containing Fe as a main component and containing P. To say that Fe is the main component specifically means that the content of Fe in the entire soft magnetic alloy is 65 at% or more.

  Hereinafter, the microstructure, distribution of Fe, and distribution of P of the soft magnetic alloy according to the present embodiment will be described with reference to the drawings.

  When the distribution of Fe in the soft magnetic alloy according to the present embodiment is observed at a thickness of 5 nm using a three-dimensional atom probe (hereinafter sometimes referred to as 3DAP), as shown in FIG. It can be observed that there are few parts.

  Here, FIG. 2 is a schematic view showing the result of observing the measurement site different from that of FIG. 1 by the same measurement method and binarizing the high and low Fe concentrations. The portion where the Fe concentration is higher than the average Fe concentration in the soft magnetic alloy is the Fe-rich phase 11, and the portion where the Fe concentration is 0.1 at% or higher than the average Fe concentration in the soft magnetic alloy is the Fe-rich phase. The phase is defined as a poor phase 13. The average concentration of Fe in the soft magnetic alloy is the same as the Fe content in the composition of the soft magnetic alloy. In FIG. 2, the Fe-rich phase 11 exists in an island shape, and the Fe-poor phase 13 is located around the island in many cases. However, the Fe-rich phase 11 does not necessarily have to exist in an island shape, and the Fe-poor phase 13 does not have to be located around the Fe-rich phase 11. The area ratio of the Fe-rich phase 11 and the area ratio of the Fe-poor phase 13 in the entire soft magnetic alloy are arbitrary. For example, the area ratio of the Fe-rich phase 11 is 20% or more and 80% or less, and the area ratio of the Fe-poor phase 13 is 20% or more and 80% or less.

  The soft magnetic alloy according to the present embodiment is characterized in that the average concentration of P in the Fe-poor phase 13 is 1.5 times or more in terms of the atomic number ratio with respect to the average concentration of P in the soft magnetic alloy. . That is, when the soft magnetic alloy according to the present embodiment is observed at a thickness of 5 nm using 3DAP, the Fe concentration varies, and more P exists in the portion where the Fe concentration is low. The soft magnetic alloy according to the present embodiment can increase the resistance of the Fe-poor phase 13 by having the above characteristics, and can improve the specific resistance ρ while having good magnetic characteristics. Good magnetic characteristics specifically mean that the saturation magnetic flux density Bs is high and the coercive force Hc is low.

  Further, it is preferable that the average concentration of P in the Fe-poor phase 13 is 1.0 at% or more and 50 at% or less. When the average concentration of P in the Fe-poor phase 13 is within the above range, the saturation magnetic flux density Bs is particularly easily improved.

  Furthermore, it is preferable that the average concentration of P in the Fe-poor phase is 3.0 times or more the average concentration of P in the Fe-rich phase 11.

  The Fe-rich phase 11 has a structure made of Fe-based nanocrystals, and the Fe-poor phase 13 has a structure made of amorphous. In the present embodiment, the Fe-based nanocrystal refers to a crystal having a particle size of 50 nm or less and an Fe content of 70 at% or more.

  There is no particular limitation on the particle size of the Fe-based nanocrystal according to the present embodiment, but the average particle size is preferably from 5 nm to 30 nm, more preferably from 10 nm to 30 nm. When the average particle size is within the above range, the coercive force Hc tends to be lower. The average particle size of the nanocrystal can be measured by powder X-ray diffraction using XRD.

  The soft magnetic alloy according to this embodiment includes, in the Fe-rich phase 11, B, C, Ti, Zr, Hf, Nb, Ta, Mo, V, W, and Cr as subcomponents in addition to Fe and P described above. , Al, Mn, Zn, Cu, Si, La, Y, S may be further included. When the Fe-rich phase 11 contains the subcomponent, the coercive force decreases while maintaining the saturation magnetic flux density. That is, the soft magnetic characteristics are improved. Particularly, a suitable soft magnetic characteristic is obtained in a high frequency range. In addition, the Fe-poor phase 13 may further include the above-described subcomponents in addition to Fe and P described above.

  The composition of the entire soft magnetic alloy can be confirmed by ICP measurement and X-ray fluorescence measurement. The composition of the Fe-rich phase 11 and the composition of the Fe-poor phase 13 can be measured by 3DAP. The average concentration of P in the Fe-rich phase 11 and the average concentration of P in the Fe-poor phase 13 can also be calculated from the above measurement results.

  The composition of the soft magnetic alloy according to the present embodiment is arbitrary except that it contains Fe and P. Preferably, the composition is within the range of the following composition (1).

Composition (1) has the following composition.
Expressed by a composition formula _{(Fe 1-α X α)} (1- (a + b + c + d + e)) Cu a M1 b P c M2 d Si e,
X is one or more selected from Co and Ni;
M1 is at least one selected from Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn, La, Y and S;
M2 is one or more selected from B and C;
0 ≦ a ≦ 0.030
0 ≦ b ≦ 0.150
0.001 ≦ c ≦ 0.150
0 ≦ d ≦ 0.200
0 ≦ e ≦ 0.200
0 ≦ α ≦ 0.500
It is.

  In the following description, the content of each element of the soft magnetic alloy is set to 100 at% for the entire soft magnetic alloy unless otherwise stated. When the composition of the soft magnetic alloy is the above composition (1), the average concentration of Fe in the soft magnetic alloy is 100 × (1−α) (1− (a + b + c + d + e)) (at%). Further, the average concentration of P in the soft magnetic alloy is 100 × c (at%).

  The content (a) of Cu is preferably 3.0 at% or less (including 0). That is, it is not necessary to contain Cu. In addition, as the Cu content is smaller, there is a tendency that a ribbon made of a soft magnetic alloy including the Fe-rich phase 11 and the Fe-poor phase 13 is easily produced by the single roll method described later. On the other hand, the effect of reducing the coercive force increases as the Cu content increases. From the viewpoint of reducing the coercive force, the content of Cu is preferably 0.1 at% or more.

  M1 is at least one selected from Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn, La, Y and S. Preferably, it is at least one selected from Zr, Hf, and Nb. There is a tendency that a ribbon made of a soft magnetic alloy containing the Fe-rich phase 11 and the Fe-poor phase 13 is easily produced by a single roll method described later.

  The content (b) of M1 is preferably 15.0 at% or less (including 0). That is, M1 may not be contained. By setting the content of M1 to 15.0 at% or less (including 0), the saturation magnetic flux density Bs can be easily improved.

  The content (c) of P is preferably 0.1 at% or more and 15.0 at% or less. By setting the content of P within the above range, the saturation magnetic flux density Bs can be easily improved.

  M2 is one or more selected from B and C.

  The content (d) of M2 is preferably 20.0 at% or less (including 0). That is, M2 need not be contained. By adding M2 within the above range, the saturation magnetic flux density Bs can be easily improved.

  The content (e) of Si is preferably 20.0 at% or less (including 0). That is, it is not necessary to contain Si.

  In the soft magnetic alloy according to the present embodiment, a part of Fe may be replaced with X. X is one or more selected from Co and Ni.

  The substitution ratio (α) of Fe to X may be 50 at% or less (including 0). If α is too high, the Fe-rich phase 11 and the Fe-poor phase 13 are hardly generated.

  The content of X (α (1- (a + b + c + d + e))) may be 40 at% or less (including 0).

  In addition, typical compositions of the soft magnetic alloy according to the present embodiment include the following compositions (2) to (4).

Composition (2) has the following composition.
Expressed by a composition formula _{(Fe 1-α X α)} (1- (a + b + c + d + e)) Cu a M1 b P c M2 d Si e,
X is one or more selected from Co and Ni;
M1 is at least one selected from Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn, La, Y and S;
M2 is one or more selected from B and C;
0 ≦ a ≦ 0.030
0.020 ≦ b ≦ 0.150
0.001 ≦ c ≦ 0.150
0.025 ≦ d ≦ 0.200
0 ≦ e ≦ 0.070
0 ≦ α ≦ 0.500
It is.

  In the composition (2), the Cu content (a) is preferably 3.0 at% or less (including 0). When the content is 3.0 at% or less, a ribbon made of a soft magnetic alloy containing the Fe-rich phase 11 and the Fe-poor phase 13 can be easily manufactured by a single roll method described later.

  In the composition (2), the content (b) of M1 is preferably from 2.0 at% to 12.0 at%. When the content is 2.0 at% or more, a ribbon made of a soft magnetic alloy containing the Fe-rich phase 11 and the Fe-poor phase 13 can be easily produced by a single roll method described later. When it is 12.0 at% or less, the saturation magnetic flux density Bs is easily improved.

  In the composition (2), the P content (c) is preferably from 1.0 at% to 10.0 at%. When the content is 1.0 at% or more, the specific resistance ρ is easily improved. When the content is 10.0 at% or less, the saturation magnetic flux density Bs is easily improved.

  In the composition (2), the content (d) of M2 is preferably from 2.5 at% to 15.0 at%. When the content is 2.5 at% or more, a ribbon made of a soft magnetic alloy containing the Fe-rich phase 11 and the Fe-poor phase 13 can be easily produced by a single roll method described later. When the content is 15.0 at% or less, the saturation magnetic flux density Bs is easily improved.

Composition (3) has the following composition.
A soft magnetic alloy represented by a composition formula (Fe _{1−α Xα} ) _{(1- (a + b + c + d + e))} Cu _a M1 _b P _c M2 _d Si _e ,
X is one or more selected from Co and Ni;
M1 is at least one selected from Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn, La, Y and S;
M2 is one or more selected from B and C;
0 ≦ a ≦ 0.030
0.010 ≦ b ≦ 0.100
0.001 ≦ c ≦ 0.070
0.020 ≦ d ≦ 0.140
0.070 ≦ e ≦ 0.175
0 ≦ α ≦ 0.500
It is.

  In the composition (3), the content (b) of M1 is preferably 1.0 at% or more and 5.0 at% or less. When the content is 5.0 at% or less, the saturation magnetic flux density Bs is easily improved.

  In the composition (3), the P content (c) is preferably 0.5 at% or more and 5.0 at% or less. When the content is 0.5 at% or more, the specific resistance ρ is easily improved. When the content is 5.0 at% or less, the saturation magnetic flux density Bs is easily improved.

  In the composition (3), the content (d) of M2 is preferably 9.0 at% or more and 11.0 at% or less. When the content is 9.0 at% or more, the coercive force Hc tends to decrease. When the content is 11.0 at% or less, the saturation magnetic flux density Bs is easily improved. Further, the content of B may be not less than 2.0 at% and not more than 10.0 at%. The content of C may be 5.0 at% or less (including 0).

  In the composition (3), the Si content (e) is preferably 10.0 at% or more and 17.5 at% or less. When the content is 10.0 at% or more, the coercive force Hc is easily improved.

Composition (4) has the following composition.
A soft magnetic alloy represented by a composition formula (Fe _{1−α Xα} ) _{(1- (a + b + c + d + e))} Cu _a M1 _b P _c M2 _d Si _e ,
X is one or more selected from Co and Ni;
M1 is at least one selected from Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn, La, Y and S;
M2 is one or more selected from B and C;
0 ≦ a ≦ 0.010
0 ≦ b <0.010
0.010 ≦ c ≦ 0.150
0.090 ≦ d ≦ 0.130
0 ≦ e ≦ 0.080
0 ≦ α ≦ 0.500
It is.

  In the composition (4), the P content (c) is preferably 1.0 at% or more and 7.0 at% or less. When the content is 7.0 at% or less, the saturation magnetic flux density Bs is easily improved.

  In the composition (4), the Si content (e) is preferably 2.0 at% or more and 8.0 at% or less. When the content is 2.0 at% or more, the coercive force Hc tends to decrease.

  Hereinafter, a method for manufacturing the soft magnetic alloy according to the present embodiment will be described.

  The method of manufacturing the soft magnetic alloy according to the present embodiment is arbitrary, and includes, for example, a method of manufacturing a ribbon of the soft magnetic alloy by a single roll method.

  In the single roll method, first, various raw materials such as pure metals of the respective metal elements contained in the finally obtained soft magnetic alloy are prepared and weighed so as to have the same composition as the finally obtained soft magnetic alloy. Then, a pure metal of each metal element is dissolved and mixed to prepare a mother alloy. The method of dissolving the pure metal is optional. For example, there is a method in which the pure metal is evacuated and then melted by high-frequency heating. The mother alloy and the finally obtained soft magnetic alloy usually have the same composition.

  Next, the produced mother alloy is heated and melted to obtain a molten metal (bath water). The temperature of the molten metal is not particularly limited, but may be, for example, 1200 to 1500C.

  FIG. 3 shows a schematic diagram of an apparatus used for the single roll method. In the single-roll method according to the present embodiment, in the chamber 35, the molten metal 32 is jetted from the nozzle 31 to the roll 33 rotating in the direction of the arrow to be supplied, whereby the ribbon 34 is rotated in the rotation direction of the roll 33. Manufactured. In the present embodiment, the material of the roll 33 is not particularly limited. For example, a roll made of Cu is used.

  In the single-roll method, the thickness of the ribbon can be adjusted mainly by adjusting the rotation speed of the roll 33. For example, the distance between the nozzle 31 and the roll 33, the temperature of the molten metal, and the like can be adjusted. By doing so, the thickness of the obtained ribbon can be adjusted. The thickness of the ribbon is not particularly limited, but may be, for example, 15 to 30 μm.

  Before the heat treatment to be described later, the ribbon is preferably in a state in which only the amorphous or microcrystals having a small particle size exist. The soft magnetic alloy according to the present embodiment is obtained by performing a heat treatment described below on such a ribbon.

It should be noted that there is no particular limitation on a method for confirming whether or not crystals having a large grain size exist in the ribbon of the soft magnetic alloy before the heat treatment. For example, the presence or absence of crystals having a particle size of about 0.01 to 10 μm can be confirmed by ordinary X-ray diffraction measurement. When crystals are present in the above-mentioned amorphous material but the volume ratio of the crystals is small, it is determined that there are no crystals by ordinary X-ray diffraction measurement. The presence or absence of crystals in this case is confirmed, for example, by using a transmission electron microscope to obtain a selected area diffraction image, a nanobeam diffraction image, a bright field image, or a high-resolution image of a sample sliced by ion milling. it can. When a selected area diffraction image or a nanobeam diffraction image is used, ring-shaped diffraction is formed when the diffraction pattern is amorphous, whereas diffraction spots due to the crystal structure are formed when the diffraction pattern is not amorphous. Is formed. When a bright-field image or a high-resolution image is used, the presence or absence of crystals can be confirmed by visual observation at a magnification of 1.00 × 10 ^{5 to} 3.00 × 10 ⁵ times. In the present specification, when it can be confirmed that there is a crystal by ordinary X-ray diffraction measurement, it is determined that “there is a crystal”, and it cannot be confirmed by ordinary X-ray diffraction measurement that there is a crystal. If the presence of crystals can be confirmed for the sliced sample by using a transmission electron microscope to obtain a selected area diffraction image, a nanobeam diffraction image, a bright field image, or a high-resolution image, the following message is displayed. Yes ".

  Here, by appropriately controlling the temperature of the roll 33 and the vapor pressure inside the chamber 35, the present inventors easily make the ribbon of the soft magnetic alloy amorphous before the heat treatment, and the concentration of P after the heat treatment. It has been found that it is easy to obtain the Fe-poor phase 11 having a high P and the Fe-rich phase 13 having a low P concentration. Specifically, the temperature of the roll 33 is set to 50 to 70 ° C., preferably 70 ° C., and the vapor pressure inside the chamber 35 is set to 11 hPa or less, preferably 4 hPa or less using Ar gas whose dew point has been adjusted. It has been found that the ribbon of the soft magnetic alloy is easily made amorphous.

  Further, the temperature of the roll 33 is preferably set to 50 to 70 ° C., and the vapor pressure inside the chamber 35 is preferably set to 11 hPa or less. By controlling the temperature of the roll 33 and the vapor pressure inside the chamber 35 within the above ranges, the molten metal 32 is uniformly cooled, and the obtained soft magnetic alloy is easily made into a uniform amorphous ribbon before heat treatment. Become. There is no particular lower limit for the vapor pressure inside the chamber. The vapor pressure may be reduced to 1 hPa or less by filling with argon whose dew point is adjusted, or the vapor pressure may be reduced to 1 hPa or less in a state close to vacuum. Further, when the vapor pressure is increased, it becomes difficult to make the ribbon before heat treatment amorphous, and even if it becomes amorphous, it becomes difficult to obtain the above preferable fine structure after heat treatment described later.

  By heat-treating the obtained ribbon 34, the above-mentioned preferable nanocrystal part 11 and amorphous part 13 can be obtained. At this time, if the ribbon 34 is completely amorphous, it becomes easy to obtain the preferable fine structure described above.

  In the present embodiment, by performing the heat treatment in two stages, it becomes easier to obtain the above preferable fine structure. The first heat treatment (hereinafter, also referred to as first heat treatment) is performed for so-called strain relief. This is to make the soft magnetic metal amorphous as uniform as possible.

  In the present embodiment, the second stage heat treatment (hereinafter, also referred to as a second heat treatment) is performed at a higher temperature than the first stage. In order to suppress the self-heating of the ribbon in the second-stage heat treatment, it is important to use a setter made of a material having a high thermal conductivity. It is more preferable that the material of the setter has a low specific heat. Conventionally, alumina is often used as the material of the setter, but in the present embodiment, a material having a higher thermal conductivity, for example, carbon or SiC can be used. Specifically, it is preferable to use a material having a thermal conductivity of 150 W / m or more. Further, it is preferable to use a material having a specific heat of 750 J / kg or less. Further, it is preferable to reduce the thickness of the setter as much as possible, place a control thermocouple under the setter, and enhance the thermal response of the heater.

  The advantage of performing the heat treatment in the above two stages will be described. The role of the first-stage heat treatment will be described. The soft magnetic alloy forms an amorphous phase by being rapidly cooled from a high temperature and solidified. At this time, since the material is rapidly cooled from a high temperature, a stress due to thermal shrinkage remains in the soft magnetic metal, causing distortion and defects. In the first heat treatment, a uniform amorphous is formed by relaxing the distortion and defects in the soft magnetic alloy by the heat treatment. Subsequently, the role of the second-stage heat treatment will be described. In the second stage heat treatment, a Fe-poor phase having a high P concentration and a Fe-rich phase (Fe-based nanocrystal) having a low P concentration are generated. Since distortion and defects can be suppressed by the first heat treatment and a uniform amorphous state is formed, the Fe-poor phase having a high P concentration and the P concentration being low by the second heat treatment are formed. An Fe-rich phase (Fe-based nanocrystal) can be generated. That is, even when heat treatment is performed at a relatively low temperature, it is possible to stably generate an Fe-poor phase having a high P concentration and an Fe-rich phase (Fe-based nanocrystal) having a low P concentration. For this reason, the heat treatment temperature in the second stage heat treatment tends to be lower than the heat treatment temperature in the case of performing the heat treatment in the conventional one stage. In other words, when heat treatment is performed in one step, a reaction in which a strain or a defect remaining at the time of forming an amorphous phase and its periphery become a Fe-rich phase (Fe-based nanocrystal) proceeds in advance. Further, a hetero phase composed of boron is formed, and the P concentration in the Fe-poor phase does not become sufficiently high. Then, the soft magnetic characteristics and the specific resistance ρ deteriorate. In addition, in order to perform heat treatment as uniformly as possible by one-step heat treatment, it is necessary to simultaneously generate an Fe-poor phase and an Fe-rich phase (Fe-based nanocrystal) in the entire soft magnetic alloy as much as possible. Therefore, the one-step heat treatment tends to have a higher heat treatment temperature than the two-step heat treatment described above.

  In the present embodiment, the preferable heat treatment temperature and the preferable heat treatment time of the first heat treatment and the second heat treatment differ depending on the composition of the soft magnetic alloy. The heat treatment temperature of the first heat treatment is generally 350 ° C. or more and 550 ° C. or less, and the heat treatment time is generally 0.1 hour or more and 10 hours or less. The heat treatment temperature of the second heat treatment is generally 550 ° C. or more and 675 ° C. or less, and the heat treatment time is generally 0.1 hour or more and 10 hours or less. However, depending on the composition, a preferable heat treatment temperature and heat treatment time may exist outside the above range.

  If the heat treatment conditions are not properly controlled, or if a suitable heat treatment apparatus is not selected, the average concentration of P in the Fe-poor phase decreases, and it becomes difficult to obtain good soft magnetic properties, and the resistivity is reduced. ρ decreases.

  As a method for obtaining the soft magnetic alloy according to the present embodiment, in addition to the above-described single roll method, there is a method for obtaining the powder of the soft magnetic alloy according to the present embodiment by, for example, a water atomizing method or a gas atomizing method. Hereinafter, the gas atomizing method will be described.

  In the gas atomization method, a molten alloy at 1200 to 1500 ° C. is obtained in the same manner as in the single roll method described above. Thereafter, the molten alloy is sprayed in a chamber to produce a powder.

  At this time, by setting the gas injection temperature at 50 to 100 ° C. and the vapor pressure in the chamber at 4 hPa or less, it becomes easier to finally obtain the above-mentioned preferable fine structure.

  After producing the powder by the gas atomizing method, by performing the heat treatment in two stages as in the case of the single roll method, it becomes easier to obtain a suitable fine structure. In addition, a soft magnetic alloy powder having particularly high oxidation resistance and good soft magnetic properties can be obtained.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to said Embodiment.

  There is no particular limitation on the shape of the soft magnetic alloy according to the present embodiment. As described above, a ribbon shape and a powder shape are exemplified, but a thin film shape, a block shape, and the like are also conceivable.

  The use of the soft magnetic alloy according to the present embodiment is not particularly limited. An example is a magnetic core. It can be suitably used as a magnetic core for inductors, especially for power inductors. The soft magnetic alloy according to the present embodiment can be suitably used for a thin film inductor, a magnetic head, and a transformer in addition to a magnetic core.

  Hereinafter, a method for obtaining the magnetic core and the inductor from the soft magnetic alloy according to the present embodiment will be described, but the method for obtaining the magnetic core and the inductor from the soft magnetic alloy according to the present embodiment is not limited to the following method.

  Examples of a method of obtaining a magnetic core from a ribbon-shaped soft magnetic alloy include a method of winding and laminating a ribbon-shaped soft magnetic alloy. When laminating a ribbon-shaped soft magnetic alloy via an insulator, a magnetic core with further improved properties can be obtained.

  As a method of obtaining a magnetic core from a powdery soft magnetic alloy, for example, there is a method in which a magnetic core is mixed with a binder and then molded using a mold. In addition, by applying an oxidation treatment, an insulating coating, or the like to the powder surface before mixing with the binder, the specific resistance is improved, and the magnetic core is adapted to a higher frequency band.

  The molding method is not particularly limited, and examples thereof include molding using a mold and molding. The type of the binder is not particularly limited, and a silicone resin is exemplified. There is no particular limitation on the mixing ratio between the soft magnetic alloy powder and the binder. For example, 1 to 10% by mass of a binder is mixed with 100% by mass of the soft magnetic alloy powder.

For example, by mixing a binder of 1 to 5% by mass with respect to 100% by mass of the soft magnetic alloy powder, and compressing and molding using a mold, the space factor (powder filling ratio) is 70% or more and 1.6. A magnetic core having a magnetic flux density of 0.4 T or more when a magnetic field of × 10 ⁴ A / m is applied and a specific resistance of 1 Ω · cm or more can be obtained. The above characteristics are characteristics superior to general ferrite cores.

Also, for example, by mixing a binder of 1 to 3% by mass with respect to 100% by mass of the soft magnetic alloy powder and compression-molding with a mold under a temperature condition equal to or higher than the softening point of the binder, the space factor is 80%. As described above, a dust core having a magnetic flux density of 0.9 T or more and a specific resistance of 0.1 Ω · cm or more when a magnetic field of 1.6 × 10 ⁴ A / m is applied can be obtained. The above characteristics are characteristics superior to general powder magnetic cores.

  Further, by performing a heat treatment after the molding as the strain relief heat treatment on the molded body forming the magnetic core, the core loss is further reduced, and the usefulness is enhanced.

  Further, an inductance component can be obtained by winding the magnetic core. There is no particular limitation on the method of winding and the method of manufacturing the inductance component. For example, a method of winding a winding around the magnetic core manufactured by the above-mentioned method for at least one turn or more may be used.

  Further, in the case of using soft magnetic alloy particles, there is a method of manufacturing an inductance component by press-molding and integrating the coil in a state where the winding coil is incorporated in the magnetic body. In this case, it is easy to obtain an inductance component corresponding to a high frequency and a large current.

  Furthermore, when using the soft magnetic alloy particles, a soft magnetic alloy paste was prepared by adding a binder and a solvent to the soft magnetic alloy particles, and a binder and a solvent were added to a conductive metal for a coil to form a paste. By heating and firing after alternately printing and laminating the conductor paste, an inductance component can be obtained. Alternatively, a soft magnetic alloy sheet is prepared using a soft magnetic alloy paste, a conductive paste is printed on the surface of the soft magnetic alloy sheet, and these are laminated and fired, so that an inductance component having a coil built in a magnetic material is formed. Obtainable.

  Here, when manufacturing an inductance component using soft magnetic alloy particles, it is preferable to use a soft magnetic alloy powder having a maximum particle size of 45 μm or less in sieve diameter and a central particle size (D50) of 30 μm or less. It is preferable for obtaining the Q characteristic. In order to set the maximum particle size to 45 μm or less in sieve diameter, a sieve having a mesh size of 45 μm may be used, and only the soft magnetic alloy powder passing through the sieve may be used.

  The use of a soft magnetic alloy powder having a large maximum particle size tends to reduce the Q value in a high frequency region. Particularly, when using a soft magnetic alloy powder having a maximum particle size of more than 45 μm in sieve diameter, The Q value may be greatly reduced. However, when the Q value in the high frequency region is not emphasized, a soft magnetic alloy powder having a large variation can be used. Since a soft magnetic alloy powder having a large variation can be produced at a relatively low cost, the cost can be reduced when a soft magnetic alloy powder having a large variation is used.

  The use of the dust core according to this embodiment is not particularly limited. For example, it can be suitably used as a magnetic core for an inductor, particularly for a power inductor.

  Hereinafter, the present invention will be specifically described based on examples.

(Experimental example 1)
Various raw material metals and the like were weighed so that a master alloy having a composition of 81.0 at% of Fe, 7.0 at% of Nb, 3.0 at% of P, and 9.0 at% of B was obtained. Then, after evacuating in the chamber, it was melted by high frequency heating to prepare a mother alloy.

  Thereafter, the produced master alloy was heated and melted to obtain a metal in a molten state at 1250 ° C., and then the metal was rolled at a roll temperature of 70 ° C., a vapor pressure of 4 hPa in the chamber, and a temperature of 30 ° C. in the chamber by the single roll method. Sprayed on a roll to create a ribbon. The thickness of the ribbon obtained by appropriately adjusting the number of rotations of the roll was set to 20 μm. The vapor pressure was adjusted by using Ar gas whose dew point was adjusted.

  Next, a heat treatment was performed on each of the produced ribbons to obtain a single-plate-shaped sample. In this experimental example, the sample No. Samples other than 6 to 10 were subjected to two heat treatments. Table 1 shows the heat treatment conditions. When performing heat treatment on each ribbon, the ribbon was placed on a setter made of the material shown in Table 1, and a control thermocouple was placed under the setter. The setter thickness at this time was unified at 1 mm. The alumina used had a thermal conductivity of 31 W / m and a specific heat of 779 J / kg. Carbon having a thermal conductivity of 150 W / m and a specific heat of 691 J / kg was used. SiC (silicon carbide) having a thermal conductivity of 180 W / m and a specific heat of 740 J / kg was used.

  After a part of each ribbon before the heat treatment was pulverized and powdered, X-ray diffraction measurement was performed to confirm the presence or absence of crystals. Furthermore, a selected area diffraction image and a bright field image at a magnification of 300,000 were observed using a transmission electron microscope to confirm the presence or absence of crystals and microcrystals. As a result, it was confirmed that the ribbons of Examples and Comparative Examples were amorphous without crystals having a particle size of 20 nm or more. Note that a case where no crystal having a particle size of 20 nm or more is present and only initial microcrystals having a particle size of less than 20 nm are present is also considered to be amorphous. In addition, it was confirmed by ICP measurement and X-ray fluorescence measurement that the composition of the entire sample was substantially the same as the composition of the mother alloy.

  Then, the saturation magnetic flux density and coercive force of each sample after the heat treatment of each ribbon were measured. Table 1 shows the results. The saturation magnetic flux density (Bs) was measured using a vibrating sample magnetometer (VSM) at a magnetic field of 1000 kA / m. The coercive force (Hc) was measured using a DC BH tracer at a magnetic field of 5 kA / m. The specific resistance (ρ) was measured by resistivity measurement by the four probe method. Furthermore, as a result of performing X-ray diffraction measurement on each sample after heat treatment of each ribbon, in all the examples of each of the experimental examples except Experimental Example 7 described later, the Fe-based nano The average grain size of the crystals was 5 to 30 nm.

  In all of the experimental examples such as Experimental Example 1, the saturation magnetic flux density Bs was 1.00T or more. The coercive force Hc was determined to be less than 10.0 A / m. Further, in the following table, the specific resistance was evaluated as １１０ when the specific resistance was 110 μΩcm or more, ○ when the specific resistance was 100 μΩcm or more and less than 110 μΩcm, and x when the specific resistance was less than 100 μΩcm. In addition, the evaluation was high in the order of ◎, 、, and ×, and the case of ◎ or ○ was evaluated as good.

  Further, an observation range of 40 nm × 40 nm × 200 nm was observed for each sample using 3DAP (three-dimensional atom probe). As a result, it was confirmed by X-ray diffraction measurement that all the samples in which no crystals and microcrystals were present contained the Fe-poor phase and the Fe-rich phase. Furthermore, it was confirmed that the Fe-poor phase was made of amorphous and the Fe-rich phase was made of nanocrystal. The average concentration of P in the Fe-poor phase and the average concentration of P in the Fe-rich phase were measured using 3DAP. Table 1 shows the results.

  According to Table 1, the material of the setter is carbon or SiC having a relatively high thermal conductivity and a relatively low specific heat, and the heat treatment temperature is performed in two stages, and the first heat treatment temperature and the second heat treatment temperature are appropriately controlled. In the example, the average concentration of P in the Fe-poor phase was higher than the average concentration of P in the entire soft magnetic alloy. Then, good results were obtained in the saturation magnetic flux density Bs, the coercive force Hc, and the specific resistance ρ. On the other hand, the material of the setter was alumina having relatively low thermal conductivity and relatively high specific heat. Sample No. 1-5 in which heat treatment was performed in one stage. Sample No. 6-11, the temperature of the first heat treatment was too low. Sample No. 19, and Sample No. 1 in which the temperature of the first heat treatment was too high. No. 24 resulted in inferior coercive force Hc and / or specific resistance ρ.

(Experimental example 2)
In Experimental Example 2, the composition of the mother alloy was changed to the composition shown in Table 2 (the composition (2) or a composition close to the composition (2)). Then, a heat treatment was performed under the same conditions as in Sample No. 16 in Table 1. Specifically, the material of the setter was carbon, the first heat treatment temperature was 450 ° C., the first heat treatment time was 1 hour, the second heat treatment temperature was 650 ° C., and the second heat treatment time was 1 hour.

  Further, various measurements were performed in the same manner as in Experimental Example 1 for all Examples and Comparative Examples. As a result of the X-ray diffraction measurement, in the comparative example in which the crystal was present, the Fe concentration was constant and the Fe-poor phase and the Fe-rich phase did not exist in the entire soft magnetic alloy. In Experimental Example 2, the saturation magnetic flux density Bs was 1.30 T or more, and more preferably 1.40 T or more. The coercive force Hc is particularly preferably 4.0 A / m or less. Table 3 shows the results.

  Tables 2 and 3 show that the examples in which the average concentration of P in the Fe-poor phase was higher than the average concentration of P in the entire soft magnetic alloy had good saturation magnetic flux density Bs, coercive force Hc, and specific resistance ρ. It became. In particular, in Examples in which the composition of the entire alloy was in the range of the above composition (1) and composition (2), the residual magnetic flux density Bs and the coercive force Hc were particularly good.

  On the other hand, in each of the comparative examples in which the Fe-poor phase was not present, the coercive force Hc was significantly increased. In particular, Sample Nos. 48 and 57 also have reduced specific resistance ρ.

  Sample No. 40a in which the soft magnetic alloy did not contain P had a lower specific resistance ρ. Further, the coercive force Hc also increased as compared with the other examples in Tables 2 and 3.

(Experimental example 3)
In Experimental Example 3, the composition of the mother alloy was changed to the composition shown in Table 4 (the composition (3) or a composition close to the composition (3)). Then, a heat treatment was performed under the same conditions as in Sample No. 16 in Table 1. Specifically, the material of the setter was carbon, the first heat treatment temperature was 450 ° C., the first heat treatment time was 1 hour, the second heat treatment temperature was 650 ° C., and the second heat treatment time was 1 hour.

  Further, various measurements were performed in the same manner as in Experimental Example 1 for all Examples and Comparative Examples. As a result of X-ray diffraction measurement, all Examples and Comparative Examples were amorphous. And, in all Examples and Comparative Examples, an Fe-poor phase and an Fe-rich phase existed. However, since sample No. 83 did not contain P, the P concentration was 0 in the Fe-poor phase, the Fe-rich phase, and the entire soft magnetic alloy. In Experimental Example 3, the saturation magnetic flux density Bs was determined to be 1.00 T or more, and more preferably 1.10 T or more. The coercive force Hc was set to 1.0 A / m or less, more preferably 0.5 A / m or less. With respect to the sample No. 83 which is a comparative example containing no P, ◎ was 130 μΩcm or more, を was a sample having a specific resistance exceeding 130 μΩcm and less than 130 μΩcm, and × was a sample having a specific resistance of 83 or less. In addition, the evaluation was high in the order of ◎, 、, and ×, and the case of ◎ or ○ was evaluated as good. The specific resistance of Sample No. 83 is less than 100 μΩcm, and the specific resistance of Sample No. 84 is 100 μΩcm or more. Table 5 shows the results.

  As can be seen from Tables 4 and 5, in each of the examples in which the average concentration of P in the Fe-poor phase was higher than the average concentration of P in the entire soft magnetic alloy, the saturation magnetic flux density Bs, the coercive force Hc, and the specific resistance ρ were good. It became. In particular, in Examples in which the composition of the entire alloy was in the range of the above-described compositions (1) and (3), the residual magnetic flux density Bs and the coercive force Hc were particularly good.

  In contrast, Sample No. 83, which did not contain P, had a lower specific resistance ρ.

(Experimental example 4)
In Experimental Example 4, the composition of the mother alloy was changed to the composition shown in Table 6 (the composition (4) or a composition close to the composition (4)). Then, a heat treatment was performed under the same conditions as in Sample No. 16 in Table 1. Specifically, the material of the setter was carbon, the first heat treatment temperature was 450 ° C., the first heat treatment time was 1 hour, the second heat treatment temperature was 650 ° C., and the second heat treatment time was 1 hour.

  Further, various measurements were performed in the same manner as in Experimental Example 1 for all Examples and Comparative Examples. As a result of X-ray diffraction measurement, all Examples and Comparative Examples were amorphous. And, in all examples, there were Fe-poor phase and Fe-rich phase. In Experimental Example 4, the saturation magnetic flux density Bs was 1.40 T or more, and more preferably 1.45 T or more. The coercive force Hc was set to 7.0 A / m or less, and more preferably 5.0 A / m or less. Table 7 shows the results.

  From Tables 6 and 7, it can be seen that the examples in which the average concentration of P in the Fe-poor phase was higher than the average concentration of P in the entire soft magnetic alloy had good saturation magnetic flux density Bs, coercive force Hc and specific resistance ρ. It became. In particular, in Examples in which the composition of the entire alloy was within the ranges of the above-described compositions (1) and (4), the residual magnetic flux density Bs and the coercive force Hc were particularly good.

(Experimental example 5)
In Experimental Example 5, evaluation was performed under the same conditions as in Experimental Example 2 except that a part of Fe of Sample No. 16 was replaced with X1. As a result of X-ray diffraction measurement, all Examples were amorphous. And, in all examples, there were Fe-poor phase and Fe-rich phase. Table 8 shows the results.

  From Table 8, it can be seen that even when a part of Fe was replaced with X1, the average P concentration in the Fe-poor phase was higher than the average P concentration in the entire soft magnetic alloy in each example. The magnetic force Hc and the specific resistance ρ were improved.

(Experimental example 6)
In Experimental Example 6, soft magnetic alloys of Sample Nos. 123 to 135 were produced under the same conditions as in Experimental Example 2 except that the type of M in Sample No. 50 was changed. Soft magnetic alloys of sample numbers 136 to 148 were produced under the same conditions as in Experimental Example 2 except that the type of M in sample number 52 was changed and b was changed from 0.080 to 0.060. Soft magnetic alloys of sample numbers 149 to 161 were produced under the same conditions as in Experimental Example 2 except that the type of M in sample number 54 was changed. And it evaluated similarly to Experimental example 2. As a result of the X-ray diffraction measurement, in the comparative example in which the crystal was present, the Fe concentration was constant and the Fe-poor phase and the Fe-rich phase did not exist in the entire soft magnetic alloy. Further, for each comparative example, the measurement of the specific resistance ρ was not performed.

表９より、Ｍの種類を変化させても軟磁性合金全体のＰの平均濃度に対してＦｅ−ｐｏｏｒ相におけるＰの平均濃度が高くなった各実施例は飽和磁束密度Ｂｓ、保磁力Ｈｃおよび比抵抗ρが良好となった。これに対し、Ｆｅ−ｐｏｏｒ相およびＦｅ−ｒｉｃｈ相が存在しなかった各比較例は保磁力Ｈｃが著しく上昇した。

From Table 9, it can be seen that, even when the type of M was changed, in each of the examples in which the average concentration of P in the Fe-poor phase was higher than the average concentration of P in the entire soft magnetic alloy, saturation magnetic flux density Bs, coercive force Hc, The specific resistance ρ became good. On the other hand, in each of the comparative examples in which the Fe-poor phase and the Fe-rich phase were not present, the coercive force Hc was significantly increased.

(Experimental example 7)
Example 16 was carried out under the same conditions as in Example 16 except that the temperature of the molten metal and the heat treatment conditions during the production of the ribbon were changed. Table 10 shows the test conditions. In Experimental Example 7, the average particle size of the initial microcrystal before the heat treatment and the average particle size of the Fe-based nanocrystal after the heat treatment were described. In all the examples, the ribbon before the heat treatment was amorphous. Table 11 shows the results of evaluation performed in the same manner as in Experimental Example 2.

  In Experimental Example 7, the saturation magnetic flux density, the coercive force and the specific resistance were good in all Examples. Further, the examples in which the average particle size of the Fe-based nanocrystals was 5 to 30 nm had better coercive force, and when the average particle size was 10 to 30 nm, the coercive force was particularly good.

(Experimental example 8)
Experimental Example 8 was performed under the same conditions as in Example 16 except that the roll temperature and the vapor pressure in the chamber were changed, and evaluated in the same manner as in Experimental Example 1. Table 12 shows the results. The sample described as “filled with argon” in Table 12 is a sample in which the chamber is filled with argon whose dew point has been adjusted and the vapor pressure in the chamber has been reduced to 1 hPa or less. The sample described as “vacuum” is a sample in which the inside of the chamber is close to a vacuum and the vapor pressure is 1 hPa or less.

  As shown in Table 12, an amorphous ribbon was obtained in Examples in which the roll temperature was 50 to 70 ° C. and the vapor pressure was controlled to 11 hPa or lower in the chamber. Then, by appropriately heat-treating the ribbon, a Fe-poor phase having a high P concentration and a Fe-rich phase having a low P concentration were formed. Then, a soft magnetic alloy having a high saturation magnetic flux density Bs, a low coercive force Hc and a high specific resistance ρ was obtained.

  On the other hand, a comparative example in which the roll temperature is 30 ° C. (sample Nos. 182 to 187), or a comparative example in which the roll temperature is 50 ° C. or 70 ° C. and the vapor pressure is higher than 11 hPa (sample Nos. 171 and 172) 176, 177), no Fe-poor phase was formed after the heat treatment, or even if a Fe-poor phase was formed, the average concentration of P in the Fe-poor phase was not sufficiently high. Then, at least one of the saturation magnetic flux density Bs, the coercive force Hc, and the specific resistance ρ deteriorated.

11 Fe-rich phase 13 Fe-poor phase 31 Nozzle 32 Molten metal 33 Roll 34 Thin ribbon 35 Chamber

Claims (8)

A soft magnetic alloy containing Fe as a main component and P,
A composition formula (Fe1-αXα) (1- (a + b + c + d + e)) represented by CuaM1bPcM2dSie,
X is one or more selected from Co and Ni;
M1 is at least one selected from Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn, La, Y and S;
M2 is one or more selected from B and C;
0 ≦ a ≦ 0.030
0.020 ≦ b ≦ 0.150
0.001 ≦ c ≦ 0.150
0.025 ≦ d ≦ 0.200
0 ≦ e ≦ 0.070
0 ≦ α ≦ 0.500
And
Fe content is 89.9 at% or less,
An Fe-rich phase and an Fe-poor phase,
The Fe-rich phase has a structure composed of Fe-based nanocrystals, and the Fe-poor phase has a structure composed of amorphous,
The average concentration of P in the Fe-poor phase is 1.5 times or more in terms of the atomic number ratio with respect to the average concentration of P in the soft magnetic alloy,
A soft magnetic alloy, wherein the average concentration of P in the Fe-poor phase is 1.0 at% or more and 50 at% or less. A soft magnetic alloy containing Fe as a main component and P,
A soft magnetic alloy represented by a composition formula (Fe1-αXα) (1- (a + b + c + d + e)) CuaM1bPcM2dSie,
X is one or more selected from Co and Ni;
M1 is at least one selected from Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn, La, Y and S;
M2 is one or more selected from B and C;
0 ≦ a ≦ 0.030
0.010 ≦ b ≦ 0.100
0.001 ≦ c ≦ 0.070
0.020 ≦ d ≦ 0.140
0.070 ≦ e ≦ 0.175
0 ≦ α ≦ 0.500
And
Fe content is 89.9 at% or less,
An Fe-rich phase and an Fe-poor phase,
The Fe-rich phase has a structure composed of Fe-based nanocrystals, and the Fe-poor phase has a structure composed of amorphous,
The average concentration of P in the Fe-poor phase is 1.5 times or more in terms of the atomic number ratio with respect to the average concentration of P in the soft magnetic alloy,
A soft magnetic alloy, wherein the average concentration of P in the Fe-poor phase is 1.0 at% or more and 50 at% or less. A soft magnetic alloy containing Fe as a main component and P,
A soft magnetic alloy represented by a composition formula (Fe1-αXα) (1- (a + b + c + d + e)) CuaM1bPcM2dSie,
X is one or more selected from Co and Ni;
M1 is at least one selected from Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn, La, Y and S;
M2 is one or more selected from B and C;
0 ≦ a ≦ 0.010
0 ≦ b <0.010
0.010 ≦ c ≦ 0.150
0.090 ≦ d ≦ 0.130
0 ≦ e ≦ 0.080
0 ≦ α ≦ 0.500
And
Fe content is 89.9 at% or less,
An Fe-rich phase and an Fe-poor phase,
The Fe-rich phase has a structure composed of Fe-based nanocrystals, and the Fe-poor phase has a structure composed of amorphous,
The average concentration of P in the Fe-poor phase is 1.5 times or more in terms of the number of atoms with respect to the average concentration of P in the soft magnetic alloy;
A soft magnetic alloy, wherein the average concentration of P in the Fe-poor phase is 1.0 at% or more and 50 at% or less.   The soft magnetic alloy according to any one of claims 1 to 3, wherein the average concentration of P in the Fe-poor phase is 3.0 times or more the average concentration of P in the Fe-rich phase.   The soft magnetic alloy according to any one of claims 1 to 4, wherein the average particle diameter of the Fe-based nanocrystal is 5 nm or more and 30 nm or less.   The soft magnetic alloy according to any one of claims 1 to 5, which has a ribbon shape.   The soft magnetic alloy according to any one of claims 1 to 5, which is in a powder form.   A magnetic component comprising the soft magnetic alloy according to claim 1.

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