JP4374633B2 - Method for producing raw material alloy for nanocomposite magnet, and method for producing nanocomposite magnet powder and magnet - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to Fe _Three The present invention relates to a method for producing a nanocomposite magnet in which fine crystals of a B compound and fine crystals of a Fe—RB system compound are mixed. In particular, the present invention relates to a raw material alloy for producing a nanocomposite magnet, a method for producing the powder, and a method for producing a nanocomposite magnet powder or a nanocomposite magnet. The present invention also relates to a motor and actuator including a nanocomposite magnet and a method for producing an Fe-based quenched alloy.
[0002]
[Prior art]
Fe _Three B / R ₂ Fe ₁₄ B-based nanocomposite magnets are Fe, which is a soft magnetic phase. _Three B microcrystal and hard magnetic phase R ₂ Fe ₁₄ B is a magnet in which B crystallites are uniformly distributed and both are magnetically coupled by exchange interaction. These microcrystals have a size on the order of nanometers (nm), and constitute a structure (nanocomposite structure) in which both microcrystalline phases are combined, so that they are called “nanocomposite magnets”.
[0003]
The nanocomposite magnet can exhibit excellent magnet characteristics due to magnetic coupling with the hard magnetic phase while including the soft magnetic phase. Moreover, as a result of the presence of a soft magnetic phase that does not contain rare earth elements such as Nd, the content of rare earth elements as a whole can be kept low. This is advantageous in reducing the manufacturing cost of the magnet and supplying the magnet stably.
[0004]
Such a nanocomposite magnet is manufactured using a method in which a melted raw material alloy is rapidly cooled, thereby once amorphized and then crystallized by heat treatment.
[0005]
In general, an amorphous alloy is produced using a melt spinning technique such as a single roll method. In the melt spinning technique, a raw material alloy is flowed down on the outer peripheral surface of a rotating cooling roll, and the raw material alloy is rapidly cooled and solidified by bringing the molten material alloy into contact with the cooling roll for a short time. In this method, the cooling rate is controlled by adjusting the rotational peripheral speed of the cooling roll.
[0006]
The alloy that has solidified and separated from the cooling roll has a ribbon (thin ribbon) shape that is thin and long in the circumferential speed direction. The alloy ribbon is crushed and sliced by a breaker, and then pulverized to a finer size by a pulverizer and pulverized.
[0007]
Thereafter, heat treatment for crystallization is performed. By this heat treatment, Fe _Three B crystallites and R ₂ Fe ₁₄ B crystallites are produced and both are magnetically coupled by exchange interaction.
[0008]
[Problems to be solved by the invention]
What metallographic structure is formed by heat treatment is important for improving the magnetic properties. However, this heat treatment has several problems in terms of controllability and reproducibility. That is, there is a problem that it is difficult to control the alloy temperature by the heat treatment apparatus as a result of generating a large amount of heat in a short time by the crystallization reaction of the amorphous raw material alloy. In particular, when heat treatment is applied to a large amount of raw material alloy powder, the temperature control tends to be impossible, so heat treatment can be performed only on a small amount of raw material alloy powder, and the processing rate (per unit time) There is a problem that the amount of powder processing) decreases. This has been a major hindrance to the mass production of magnet powder.
[0009]
In addition, when producing a Fe-based rapidly solidified alloy by the same method, it is difficult to uniformly control the cooling rate during the rapid solidification, so that there is a problem that an unnecessary structure may appear in the rapidly solidified alloy. there were. This problem was particularly noticeable when the roll peripheral speed was lowered and the cooling speed was lowered.
[0010]
The present invention has been made in view of these points, and its main object is to reduce the heat of crystallization and thereby efficiently produce a magnet powder having a fine and homogeneous metal structure with good reproducibility. It is an object to provide a raw material alloy (powder) for a nanocomposite magnet and a method for producing the same.
[0011]
Another object of the present invention is to provide a method for producing a nanocomposite magnet powder excellent in magnet performance and a method for producing a nanocomposite magnet.
[0012]
Still another object of the present invention is to provide a motor and an actuator including a nanocomposite magnet having such excellent characteristics.
[0013]
Still another object of the present invention is to provide an Fe-based rapidly solidified alloy manufacturing method and an Fe-based alloy manufacturing method in which the cooling rate can be easily controlled uniformly.
[0014]
[Means for Solving the Problems]
The manufacturing method of the raw material alloy for the nanocomposite magnet is generally expressed by Fe _100-xy R _x B _y , Fe _100-xyz R _x B _y Co _z , Fe _100-xyu R _x B _y M _u Or Fe _100-xyzu R _x B _y Co _z M _u R is a raw material alloy for a nanocomposite magnet, wherein R contains 90 atomic% or more of one or both of Pr and Nd, and the balance is 0% of another lanthanum series element or one or more elements of Y More than 10% rare earth element, M is Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Hf, Ta, W, Pt, Pb, Au and Ag One or more elements selected from the group consisting of: composition ratio x, y, z and u are 2 ≦ x ≦ 6, 16 ≦ y ≦ 20, 0.2 ≦ z ≦ 7, and 0.01 ≦ The method for producing a raw material alloy for a nanocomposite magnet that satisfies u ≦ 7 includes a step of rapidly solidifying a molten metal of the raw material alloy by a liquid quenching method using a cooling roll, and in the rapid solidification step, Rapid solidification with reduced pressure atmosphere Run in air, thereby characterized in that to produce a rapidly solidified alloy in the metallic glass state.
[0015]
The absolute pressure of the reduced-pressure atmosphere is preferably 50 kPa or less.
[0016]
The method may further include a step of producing powder from the rapidly solidified raw material alloy.
[0017]
In the rapid solidification step, the cooling rate of the alloy is 5 × 10 ^Four ~ 5x10 ⁶ It is preferable that the temperature of the alloy is lowered to 400 to 800 ° C. lower than the temperature Tm of the alloy before quenching by K / sec.
[0018]
The method for producing a nanocomposite magnet powder according to the present invention has a general formula of Fe _100-xy R _x B _y , Fe _100-xyz R _x B _y Co _z , Fe _100-xyu R _x B _y M _u Or Fe _100-xyzu R _x B _y Co _z M _u R is an alloy for nanocomposite magnets, wherein R contains 90 atomic% or more of one or both of Pr and Nd, and the balance is 0% or more of other lanthanum series elements or one or more elements of Y It is a rare earth element containing less than 10%, and M is from Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Hf, Ta, W, Pt, Pb, Au, and Ag. One or more elements selected from the group consisting of x, y, z and u with 2 ≦ x ≦ 6, 16 ≦ y ≦ 20, 0.2 ≦ z ≦ 7, and 0.01 ≦ u A step of preparing a powder of the raw material alloy for nanocomposite magnets satisfying ≦ 7, and a heat treatment is performed on the powder of the raw material alloy for nanocomposite magnets, whereby Fe _Three A method for producing a nanocomposite magnet powder comprising the step of crystallizing a B compound and a Fe—R—B-based compound, wherein the step of preparing the raw material alloy powder for the nanocomposite magnet comprises the step of: Including a step of rapidly solidifying a molten metal in a reduced pressure atmosphere by a liquid quenching method using a cooling roll to produce a rapidly solidified alloy in a metallic glass state, and a step of producing the powder from the rapidly solidified alloy. It is characterized by.
[0019]
The absolute pressure of the reduced-pressure atmosphere is preferably 50 kPa or less.
[0020]
In the rapid solidification step, the cooling rate of the alloy is 5 × 10 ^Four ~ 5x10 ⁶ It is preferable that the temperature of the alloy is lowered to 400 to 800 ° C. lower than the temperature Tm of the alloy before quenching by K / sec.
[0021]
The manufacturing method of the nanocomposite magnet has the general formula Fe _100-xy R _x B _y , Fe _100-xyz R _x B _y Co _z , Fe _100-xyu R _x B _y M _u Or Fe _100-xyzu R _x B _y Co _z M _u R is an alloy for nanocomposite magnets, wherein R contains 90 atomic% or more of one or both of Pr and Nd, and the balance is 0% or more of other lanthanum series elements or one or more elements of Y It is a rare earth element containing less than 10%, and M is from Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Hf, Ta, W, Pt, Pb, Au, and Ag. And at least one element selected from the group consisting of 2 ≦ x ≦ 6, 16 ≦ y ≦ 20, 0.2 ≦ z ≦ 7.0, 0.01 ≦ a step of preparing a raw material alloy powder for nanocomposite magnets satisfying u ≦ 7, and a heat treatment is performed on the raw material alloy powder for nanocomposite magnets, whereby Fe _Three A method for producing a nanocomposite magnet comprising a step of performing crystallization of a B compound and a Fe—R—B-based compound, and a step of forming a molded body using the raw material alloy powder after the heat treatment, The step of preparing a powder of the raw material alloy for the nanocomposite magnet includes a step of rapidly solidifying the molten metal of the raw material alloy in a reduced pressure atmosphere by a liquid quenching method using a cooling roll, and the powder from the rapidly solidified raw material alloy. The process of producing.
[0022]
The absolute pressure of the reduced-pressure atmosphere is preferably 50 kPa or less.
[0023]
In the rapid solidification step, the cooling rate of the alloy is 5 × 10 ^Four ~ 5x10 ⁶ It is preferable that the temperature of the alloy is lowered to 400 to 800 ° C. lower than the temperature Tm of the alloy before quenching by K / sec.
[0024]
The step of forming the compact includes a step of producing a bonded magnet using the raw material alloy powder after the heat treatment.
[0025]
The motor of this invention is equipped with the nanocomposite magnet manufactured by the manufacturing method of the said nanocomposite magnet.
[0026]
The method for producing an Fe-based rapidly solidified alloy according to the present invention is a method for producing an Fe-based rapidly solidified alloy comprising a step of rapidly solidifying a molten Fe-based alloy by a liquid quenching method using a cooling roll, wherein In the process, rapid solidification of the Fe-based alloy is performed in a reduced-pressure atmosphere, thereby forming an Fe-based rapidly solidified alloy having a crystalline phase of 10% or less of the whole.
[0027]
The absolute pressure in the reduced-pressure atmosphere is preferably 10 kPa or less.
[0028]
The Fe-based alloy is produced by rapidly solidifying the molten Fe-based alloy in a reduced-pressure atmosphere by a liquid quenching method using a cooling roll, whereby the Fe-based rapid solidification is achieved with a crystalline phase of 10% or less. A step of forming an alloy and a step of heating the Fe-based rapidly solidified alloy to crystallize the Fe-based rapidly solidified alloy.
[0029]
The absolute pressure in the reduced-pressure atmosphere is preferably 10 kPa or less.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the general formula is Fe _100-xy R _x B _y , Fe _100-xyz R _x B _y Co _z , Fe _100-xyu R _x B _y M _u Or Fe _100-xyzu R _x B _y Co _z M _u After producing a melt of the alloy for a nanocomposite magnet represented by any of the above, the melt of the alloy is rapidly cooled and solidified.
[0031]
Here, R is a rare earth element containing one or both of Pr and Nd at 90 atomic% or more, and the balance containing other lanthanum series elements or one or more elements of Y from 0% to less than 10%, M is one or more elements selected from the group consisting of Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Hf, Ta, W, Pt, Pb, Au, and Ag It is. The composition ratios x, y, z, and u satisfy 2 ≦ x ≦ 6, 16 ≦ y ≦ 20, 0.2 ≦ z ≦ 7, and 0.01 ≦ u ≦ 7. The reasons for limiting the composition will be described later.
[0032]
The present inventor has set the cooling rate of 5 × 10 5 when the alloy melt is rapidly solidified. ^Four ~ 5x10 ⁶ It has been found that K / sec is preferable. Moreover, it turned out that the alloy solidified by cooling at such a cooling rate and its powder are in a metallic glass state as described below. That is, it contains a metastable phase Z in which the Bragg scattering peak in powder X-ray diffraction corresponds to a crystal plane interval of 0.179 nm ± 0.005 nm, and the intensity of the Bragg reflection peak is 5% of the maximum intensity of the halo pattern. The intensity of the (110) Bragg scattering peak of the body-centered cubic Fe is less than 5% of the maximum intensity of the halo pattern.
[0033]
Further, when the present inventors rapidly solidify the above alloy in a normal pressure atmosphere using the single roll method, an atmospheric gas is caught between the molten alloy and the outer peripheral surface of the roll, and the atmospheric gas is caught. As a result of insufficient cooling at the part, it was found that the properties of the rapidly solidified alloy ribbon (alloy ribbon) partially deteriorated. Hereinafter, this phenomenon will be described with reference to the drawings.
[0034]
FIGS. 1 (a) and 1 (b) schematically show cross sections of alloy ribbons 101 and 102 obtained when the above alloy is rapidly solidified in a normal pressure atmosphere using a single roll method as in the prior art. . FIG. 1A shows a case where the roll peripheral speed is relatively slow (roll peripheral speed: less than 10 m / second), and FIG. 1B shows a case where the roll peripheral speed is relatively high (roll peripheral speed: 10 m / second). Seconds or more). When the roll peripheral speed is low, the formed alloy ribbon 101 is relatively thick, and when the roll peripheral speed is high, the formed alloy ribbon 102 is relatively thin. 1A and 1B, a plurality of recesses 105 are formed on the lower surface of the alloy ribbons 101 and 102, that is, the surface that has been in contact with the cooling roll. The recess 105 is generated as a result of the atmospheric gas being caught between the molten alloy and the outer peripheral surface of the roll. In the recesses of the alloy ribbons 101 and 102, the cooling by the cooling roll is only insufficiently performed, and the cooling rate is locally slower than the other portions. In particular, in the case of FIG. 1A, since the cooling rate is originally set to be relatively slow, the cooling rate of the portion of the recess 105 of the alloy ribbon 101 deviates from the desired range, and the α-Fe phase 106 is generated. Will be. This α-Fe phase 106 does not disappear after heat treatment, and Fe _Three B / Nd ₂ Fe ₁₄ Deteriorates the characteristics of the B-based nanocomposite magnet. On the other hand, in the case of FIG. 1B, the roll peripheral speed is high, and the alloy is rapidly cooled as a whole. For this reason, the α-Fe phase is hardly generated in the recess 105 of the alloy ribbon 102, and instead, it is considered that a “metastable phase Z” described later is generated in the vicinity of the recess.
[0035]
FIGS. 1C and 1D are drawings corresponding to FIGS. 1A and 1B, respectively, and are cross-sections of alloy ribbons 103 and 104 produced when rapid solidification is performed in a reduced-pressure atmosphere. Is shown. In both cases of FIGS. 1C and 1D, no concave portion is formed on the lower surface of the alloy ribbons 103 and 104, that is, the surface in contact with the cooling roll. This is because the atmospheric gas was hardly involved between the molten alloy and the outer peripheral surface of the roll, and the molten alloy was in uniform contact with the outer peripheral surface of the roll. As a result, even when the roll peripheral speed is lowered and thereby the cooling speed is reduced, the surface shape of the alloy ribbon 103 does not deteriorate as shown in FIG. It is suppressed. On the other hand, in the case of FIG. 1 (d), the alloy is cooled uniformly, but the cooling rate itself is high, so that the “metastable phase Z” described later is hardly generated.
[0036]
Thus, in order to suppress the entrainment of atmospheric gas between the molten alloy and the cooling roll, the absolute pressure of the quenching chamber is preferably 50 kPa or less, and more preferably 30 kPa or less. The lower limit of the preferable range of the absolute pressure is about 1 kPa. This is because there is little significance in setting a lower pressure than this in order to prevent the atmospheric gas from being involved.
[0037]
When heat treatment is applied to the rapidly solidified alloy or its powder by the method of the present embodiment, Fe _Three Crystallization of B crystallites and R—Fe—B system crystallites occurs, and a nanocomposite magnet structure having excellent magnet properties is developed.
[0038]
The raw material alloy produced by the production method of the present invention has the metal glass structure as described above before being subjected to the heat treatment for crystallization, and does not show long-range periodic order. This is confirmed by line diffraction. According to the experiment of the present inventor, by adjusting the cooling rate of the molten alloy, a metallic glassy alloy containing the metastable phase Z can be formed, and extremely excellent magnetic properties are exhibited by the subsequent heat treatment. Will be.
[0039]
The first reason why the magnet manufactured using the method of the present invention is excellent in magnet characteristics is that the adhesion between the molten metal and the cooling roll is improved by reducing the atmospheric gas, and the molten metal is uniformly cooled. This is because even if the roll peripheral speed is decreased, a high-quality metallic glass-like alloy containing almost no α-Fe phase can be formed.
[0040]
The second reason is that in the above alloy in the metallic glass state, Fe _Three This is because fine precursors (embryo) necessary for crystal growth such as B are dispersed at a high density. Therefore, when heat treatment is performed, crystal growth proceeds with short-range order represented by a large number of precursors present in the alloy as a nucleus, and as a result, a fine and homogeneous crystal structure is formed. Fe _Three Since crystallization of B proceeds by atomic diffusion in a very short range, there is an advantage that the crystallization can be achieved at a relatively low temperature.
[0041]
Fe _Three Crystallization of B occurs at a temperature of 560-600 ° C. As this crystallization progresses, rare earth elements such as Nd are transformed into Fe. _Three The amorphous region around B is expelled, and the composition of the portion is Nd ₂ Fe ₁₄ Approach B As a result, Nd ₂ Fe ₁₄ Although B is a ternary compound having a complicated structure, it crystallizes without requiring long-distance atomic diffusion. Nd ₂ Fe ₁₄ The temperature at which B crystallizes is Fe _Three It is about 610-690 degreeC higher by about 20-90 degreeC than the temperature which the crystallization of B is completed.
[0042]
Thus, in the raw material alloy according to the present invention, Fe _Three Crystallization of B and Nd ₂ Fe ₁₄ Since crystallization of B can be performed separately in different temperature ranges, a large heat of reaction accompanying crystallization does not occur in a short time, and a fine metal structure of about 20 nm can be generated with good reproducibility. This is important in controlling the heat treatment process for alloy crystallization. That is, if crystallization progresses at once with high heat of reaction, the temperature of the alloy cannot be controlled within a predetermined range.
[0043]
Although the actual structure of the metastable phase Z has not yet been confirmed, the presence of the metastable phase Z can be quantitatively grasped because it has a steep diffraction line peak at a specific position by X-ray diffraction. The metastable phase Z shows a sharp Bragg scattering peak at a position corresponding to a crystal plane spacing of 0.179 nm ± 0.005 nm, and has a crystal plane spacing of 0.417 nm ± 0.005 nm and 0.267 nm ± 0.005 nm. The Bragg scattering peak at substantially the same level is also shown at a position corresponding to the crystal plane spacing. In addition to these, a Bragg peak may also be observed at 0.134 nm ± 0.005 nm.
[0044]
The metastable phase Z present in the alloy after rapid solidification is thermally decomposed by heat treatment for magnetization, and finally the metastable phase Fe. _Three It is considered that B is generated. This process is similar to Fe _Three It is considered that the formation of heterogeneous nuclei of B proceeds at a temperature lower than the most frequently occurring temperature and in a relatively wide range of temperatures.
[0045]
The metastable phase Z is formed near the surface of the solidified ribbon when the cooling rate during rapid solidification is relatively low, and is not generated when the cooling rate is high as in the conventional rapid solidification method. is doing. In the present invention, the cooling rate is adjusted so that the metastable phase Z is generated in an appropriate amount. That is, in the present invention, the presence of the metastable phase Z is used as an index when determining an appropriate cooling rate. Even when the composition of the alloy is changed or the cooling device is changed, an optimum material alloy of the present invention can be easily obtained by resetting the cooling rate based on the amount of metastable phase Z generated. . It is unclear whether the metastable phase Z itself plays a major role for microcrystallization. However, it has been found that if the quenching condition is controlled so that the metastable phase Z is formed at a certain ratio, high magnetic properties can be obtained by the subsequent heat treatment.
[0046]
Hereinafter, what happens when the cooling rate deviates from the predetermined range will be described.
[0047]
First, a case where the cooling rate is too fast will be described.
[0048]
If the cooling rate is too fast, the alloy will be almost completely amorphous. In that case, Fe _Three Since the number of sites in which heterogeneous nuclei of B are generated is extremely small, Fe treatment _Three B crystal grains grow greatly. As a result, a fine crystal structure cannot be formed, the coercive force and the like are lowered, and excellent magnetic properties cannot be exhibited.
[0049]
Thus, when the cooling rate is too fast, the generation of the metastable phase Z is suppressed. When the abundance ratio is evaluated by the intensity of the Bragg scattering peak in X-ray diffraction, the intensity of the Bragg scattering peak due to the metastable phase Z is less than 5% of the maximum intensity of the halo pattern, which is at a level hardly observed. In this case, Fe _Three A large driving force is required to generate nuclei for B crystallization, and the crystallization reaction temperature moves to the high temperature side. In addition, in this case, once the crystallization reaction starts, the crystallization reaction proceeds explosively, so that a large amount of heat is generated in a short time and the raw material alloy temperature becomes high. As a result, the raw material alloy temperature rises to a level at which atomic diffusion occurs at a high speed, the controllability of the reaction process is lost, and only a coarse metal structure can be obtained.
[0050]
When the heat treatment for crystallization is performed using a continuous heat treatment method, it is necessary to suppress the supply amount of the raw material alloy powder per unit time so that the heat of crystallization reaction can be dissipated to the surroundings by thermal diffusion. Even when the batch processing method is used instead of the continuous heat treatment method, it is necessary to greatly limit the processing amount of the raw material alloy powder for the same reason.
[0051]
Next, a case where the cooling rate is too slow will be described.
[0052]
If the cooling rate is too slow, periodic regularity is formed over a long range. In many cases, Fe which is a stable phase is crystallized. Thus, when the cooling rate is too slow, the intensity of the Bragg reflection peak of the crystal phase is observed over the halo pattern. When the (110) Bragg scattering peak, which is the strongest line of body-centered cubic Fe, is observed at a position with an interplanar spacing of 0.203 nm and the intensity is 5% or more of the maximum intensity of the halo pattern, “the cooling rate is slow. Too much ". Fe may be high-temperature phase gamma iron at the time of formation, but is transformed into body-centered cubic iron at room temperature.
[0053]
Even if the cooling rate is set within an appropriate range for the entire alloy, as described above, if the atmospheric gas is caught between the alloy and the outer peripheral surface of the roll, the cooling rate is locally reduced. Then, a body-centered cubic Fe phase appears.
[0054]
Finally, a case where the cooling rate is not so slow as to produce Fe crystal nuclei but has not reached a preferable cooling rate will be described. In this case, since the crystal nucleus embryo has already grown into a large structure, it becomes impossible to form a fine crystal structure in a subsequent heat treatment step. The alloy in this case contains a large amount of metastable phase Z, and according to powder X-ray diffraction, the intensity of the Bragg reflection peak of metastable phase Z is extremely high, exceeding 200% of the maximum intensity of the halo pattern.
[0055]
Thus, the raw material alloy in which the ratio of the metastable phase Z is very large can only generate a coarse metal structure by the subsequent heat treatment. The reason is Fe _Three This is because the number of nucleation sites of B decreases and the growth of Fe crystal grains as an equilibrium phase occurs preferentially. When the metal structure after heat treatment becomes coarse, Fe _Three Magnetization direction of B and Fe and Nd ₂ Fe ₁₄ The magnetic coupling via exchange interaction with the magnetization direction of B becomes insufficient. As a result, the high magnetic properties of the original nanocomposite magnet cannot be expressed.
[0056]
The characteristics of the raw material alloy for nanocomposite magnets produced by the method of the present invention are summarized as follows.
[0057]
1. Since the alloy is rapidly solidified in a reduced-pressure atmosphere, uniform cooling by a cooling roll is realized, and a situation in which Fe crystal nuclei are locally generated can be avoided.
[0058]
2. Fe _Three Since crystallization of B proceeds by atomic diffusion in the very short range, Fe _Three B can be crystallized at a relatively low temperature.
[0059]
3. Fe _Three The temperature range where crystallization of B proceeds is Nd ₂ Fe ₁₄ Since it deviates from the temperature range where crystallization of B proceeds, each crystallization occurs separately in time during the heat treatment.
[0060]
4). By the above items 2 and 3, crystallization can be performed with good controllability without large heat of crystallization reaction. As a result, the raw material powder throughput in the heat treatment step can be improved without deteriorating the magnet characteristics.
[0061]
5. Fe _Three Since the crystal nuclei necessary for crystallization of B are present in the raw material alloy at a high density, a fine and uniform metal structure can be formed by magnetizing heat treatment. This makes it possible to develop high magnet properties.
[0062]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0063]
[Production method of raw material alloy and its powder]
In this embodiment, a raw material alloy is manufactured using the apparatus shown in FIGS. 2 (a) and 2 (b). In order to prevent the oxidation of the raw material alloy containing rare earth elements that are easily oxidized, the alloy manufacturing process is executed in an inert gas atmosphere. As the inert gas, a rare gas such as helium or argon is preferably used. Since nitrogen easily reacts with rare earth elements, it is not preferable to use it as an inert gas.
[0064]
The apparatus shown in FIG. 2 includes a raw material alloy melting chamber 1 and a quenching chamber 2 that can maintain a vacuum or an inert gas atmosphere and adjust the pressure.
[0065]
The melting chamber 1 is a melting furnace 3 that melts the raw material 20 blended so as to have a desired magnet alloy composition at a high temperature, a hot water storage container 4 having a hot water discharge nozzle 5 at the bottom, and a mixture while suppressing entry of air. And a blended raw material supply device 8 for supplying the raw material into the melting furnace 3. The hot water storage container 4 has a heating device (not shown) that stores the molten alloy 21 of the raw material alloy and can maintain the temperature of the hot water at a predetermined level.
[0066]
The rapid cooling chamber 2 includes a rotary cooling roll 7 for rapidly solidifying the molten metal 21 discharged from the hot water nozzle 5, and a breaker 10 for crushing the raw material alloy thus rapidly solidified in the rapid cooling chamber 2. According to this apparatus, melting, tapping, rapid solidification, breaking, etc. can be performed continuously and in parallel.
[0067]
In this apparatus, the atmosphere in the melting chamber 1 and the quenching chamber 2 and the pressure thereof are controlled within a predetermined range. Therefore, atmospheric gas supply ports 1b, 2b, 8b, and 9b and gas exhaust ports 1a, 2a, 8a, and 9a are provided at appropriate locations in the apparatus. In particular, the gas exhaust port 2a is connected to a pump in order to control the absolute pressure in the quenching chamber 2 within the range of vacuum to 50 kPa.
[0068]
The melting furnace 3 can be tilted, and the molten metal 21 is appropriately poured into the hot water storage container 4 through the funnel 6. The molten metal 21 is heated in the hot water storage container 4 by a heating device (not shown).
[0069]
The hot water discharge nozzle 5 of the hot water storage container 4 is disposed in the partition wall between the melting chamber 1 and the quenching chamber 2 and causes the molten metal 21 in the hot water storage container 4 to flow down to the surface of the cooling roll 7 positioned below. The orifice diameter of the hot water nozzle 5 is, for example, 0.5 to 2.0 mm. When the viscosity of the molten metal 21 is large, the molten metal 21 is less likely to flow through the hot water nozzle 5, but in this embodiment, the quenching chamber 2 is held at a lower pressure than the melting chamber 1. During this time, a pressure difference is formed, and the molten metal 21 is smoothly discharged.
[0070]
The surface of the cooling roll 7 is covered with, for example, a chromium plating layer, and the diameter of the cooling roll 7 is, for example, 300 to 500 mm. The water cooling capacity of the water cooling device provided in the cooling roll 7 is calculated and adjusted according to the solidification latent heat per unit time and the amount of hot water.
[0071]
According to this apparatus shown in FIG. 2, for example, a total of 20 kg of raw material alloy can be rapidly solidified in 15 to 30 minutes. The alloy formed in this way is an alloy ribbon (alloy ribbon) 22 having a thickness of 70 to 150 μm and a width of 1.5 to 6 mm before breaking, but the alloy having a length of about 2 to 150 mm by the breaking device 10. After being crushed into thin pieces 23, it is recovered by the recovery mechanism unit 9. In the example of the apparatus shown in the figure, the recovery mechanism unit 9 is provided with a compressor 11 so that the thin piece 23 can be compressed.
[0072]
Next, a method for producing a raw material alloy using the apparatus of FIG. 2 will be described.
[0073]
First, the general formula is Fe _100-xy R _x B _y , Fe _100-xyz R _x B _y Co _z , Fe _100-xyu R _x B _y M _u Or Fe _100-xyzu R _x B _y Co _z M _u A melt 21 of the alloy for a nanocomposite magnet represented by any of the above is prepared and stored in the hot water storage container 4 of the melting chamber 1. Here, the ranges of R, M, composition ratios x, y, z, and u are as described above.
[0074]
Next, the molten metal 21 is discharged from the hot water nozzle 5 onto the water-cooled roll 7 in the reduced-pressure Ar atmosphere, rapidly cooled by contact with the water-cooled roll 7, and solidified. As the rapid solidification method, it is necessary to use a method capable of controlling the cooling rate with high accuracy. In this embodiment, a single roll method, which is one of the liquid rapid cooling methods, is used.
[0075]
In this embodiment, when the molten metal 21 is cooled and solidified, the cooling rate is 5 × 10 5. ^Four ~ 5x10 ⁶ K / second. At this cooling rate, the temperature of the alloy is lowered to a temperature lower by ΔT1. Since the temperature of the molten alloy 21 before the rapid cooling is close to the melting point Tm (for example, 1200 to 1300 ° C.), the temperature of the alloy decreases from Tm to (Tm−ΔT1) on the cooling roll 7. According to the experiment of the present inventor, ΔT1 is preferably in the range of 400 to 800 ° C. from the viewpoint of improving the final magnet characteristics.
[0076]
The time for which the molten alloy 21 is cooled by the cooling roll 7 corresponds to the time from the contact of the alloy with the outer peripheral surface of the rotating cooling roll 7 until it leaves, and in the case of this embodiment, 0.5 to 2 mm. Seconds. Meanwhile, the temperature of the alloy further decreases by ΔT2 and solidifies. Thereafter, the solidified alloy leaves the cooling roll 7 and flies in an inert atmosphere. While the alloy is in the form of a ribbon, the temperature is lowered to (Tm−ΔT1−ΔT2) as a result of the heat deprived from the atmospheric gas. ΔT2 varies depending on the size of the apparatus and the pressure of the atmospheric gas, but is about 100 ° C. or higher.
[0077]
In the present embodiment, when the temperature of the alloy ribbon 22 reaches (Tm−ΔT1−ΔT2), the crushing process is quickly performed in the apparatus, and the alloy flakes 23 are produced on the spot. Therefore, it is preferable to adjust the size of (ΔT1 + ΔT2) so that (Tm−ΔT1−ΔT2) is lower than the vitrification temperature Tg of the alloy. If (Tm−ΔT1−ΔT2) ≧ Tg, the alloy is in a softened state and its fracture becomes difficult. When the fracture / pulverization process of the solidified alloy is separately performed by another apparatus, the alloy temperature is lowered to about room temperature, and therefore, it is not necessary to consider the size of (ΔT1 + ΔT2).
[0078]
The absolute pressure in the quenching chamber 2 is preferably set in the range of vacuum to 50 kPa, and more preferably in the range of 2 to 10 kPa. If the molten metal 21 flows down onto the cooling roller 7 in such a reduced-pressure atmosphere, there is no possibility that atmospheric gas will be trapped between the molten metal 21 and the surface of the roller 7, and the cooling rate of the molten metal 21 is made lower than before. However, the cooling state is made uniform, and the alloy ribbon 22 having excellent surface shape and structure can be obtained.
[0079]
Further, as in this embodiment, if the crushing process of the solidified alloy by the crushing device is performed immediately following the rapid solidification process, the quenched alloy discharged from the cooling roll as a long alloy ribbon can be contained in a relatively narrow space. It can be collected in a compact manner. If the rapid solidification device and the crushing device are configured separately, it is necessary to store the rapid cooling alloy as a long ribbon once in a bulky state.
[0080]
If the alloy flakes crushed by the breaking device are further pulverized by a known mechanical pulverization device, an alloy powder having a size suitable for the heat treatment step and the subsequent forming step can be produced. In the present embodiment, the alloy is coarsely pulverized to about 850 μm or less with a power mill device, and then pulverized with a pin disk mill device to a particle size of about 150 μm.
[0081]
[Production method of nanocomposite magnet powder]
Below, the heat processing method performed with respect to the said raw material alloy powder is demonstrated, referring FIG.
[0082]
FIG. 3 shows a powder firing furnace apparatus using a hoop belt. The apparatus includes rotating rolls 24 and 25 that are instructed to be rotatable by a main body 28, and a hoop belt 26 that is driven at a predetermined speed in one direction by the rotation of the rotating rolls 24 and 25. The raw material alloy powder is supplied to the raw material feed position A on the hoop belt 26 and conveyed to the left in the figure. The powder supplied onto the hoop belt 26 is leveled by the sliding plate 27, whereby the height of the powder is adjusted to a certain level or less (for example, 2 to 4 mm in height). Thereafter, the powder enters a heating zone surrounded by a metal tube where it undergoes a heat treatment for microcrystallization. In the heating zone (for example, length 1100 mm), heaters (not shown) are arranged in, for example, three zones (the length of one zone is 300 mm, for example). As the powder moves through the heating zone, it undergoes a heat treatment. A cooling zone C having a length of, for example, 800 mm exists at the subsequent stage of the heating zone, and the powder is cooled by passing through a water-cooled metal cylinder. The cooled powder is collected by a collecting device (not shown) at the lower left of the rotating roller 25.
[0083]
According to this heat treatment apparatus, the heat treatment process can be controlled by adjusting the moving speed of the hoop belt 26 with respect to the length of the given heating zone.
[0084]
As the heat treatment step, for example, the heat treatment temperature may be increased to 590 to 700 ° C. at a temperature rising rate of 100 to 150 ° C./min, and the state may be maintained for about 5 to 15 minutes. Thereafter, the alloy temperature is lowered to a room temperature level at a temperature drop rate of 100 to 150 ° C./min.
[0085]
In order to increase the amount of processed powder in the heat treatment, the width of the hoop belt 26 is widened and the amount of powder supplied per unit length of the hoop belt 26 is increased, while the length of the heating zone is increased, and the rotating roller The rotational peripheral speeds 24 and 25 may be increased. According to the alloy powder according to the present invention, since the heat of crystallization reaction is not rapidly generated during the heat treatment, the temperature control of the alloy powder in the heat treatment process is easy. As a result, even if the powder supply amount is increased, a magnet powder having stable magnetic properties can be produced.
[0086]
The raw material powder subjected to the heat treatment by the heat treatment apparatus is microcrystallized as described above, and can exhibit the characteristics as a nanocomposite magnet. Thus, the raw material alloy powder that was in the metallic glass state and did not exhibit the properties as the hard magnetic material before the heat treatment is changed into a nanocomposite magnet alloy powder having excellent magnetic properties by the heat treatment.
[0087]
[Magnet manufacturing method]
Below, the method to manufacture a magnet from the said nanocomposite magnet alloy powder is demonstrated.
[0088]
First, a compound is produced by adding the binder and additive which consist of an epoxy resin to the nanocomposite magnet alloy powder obtained as mentioned above, and knead | mixing them. Next, after press molding by a molding apparatus having a molding space having a desired shape of the compound, a final bonded magnet can be obtained through a heat curing process, a cleaning process, a coating process, an inspection process, and a magnetizing process.
[0089]
The molding process is not limited to the compression molding described above, and may be a known extrusion molding, injection molding, or rolling molding. The magnet powder is kneaded with a plastic resin or rubber according to the type of molding method employed.
[0090]
In addition, in the case of injection molding, a high softening point resin such as PPS can be used in addition to polyimide and nylon widely used as a resin. This is because the magnet powder of the present invention is formed from a low-rare earth alloy, so that it is not easily oxidized, and the magnet characteristics are not deteriorated even when injection molding is performed at a relatively high temperature.
[0091]
Further, since the magnet of the present invention is hardly oxidized, it is not necessary to coat the final magnet surface with a resin film. Therefore, for example, the magnet powder and the molten resin of the present invention can be press-fitted into a slot of a part having a complicatedly shaped slot, thereby manufacturing a part integrally having a complicatedly shaped magnet. Is possible.
[0092]
[motor]
Next, an embodiment of a motor provided with the magnet manufactured as described above will be described.
[0093]
The motor of this embodiment is a PM (Permanent Magnet) type motor, and a bond magnet manufactured by the above-described manufacturing method is used as a spring magnet of an integrated rotor.
[0094]
Needless to say, the magnet of the present invention is suitably used for other types of motors and actuators besides this type of motor.
[0095]
Examples of the present invention and comparative examples will be described below.
[0096]
[Examples and Comparative Examples]
In this example, the aforementioned rapid solidification process was performed in an argon atmosphere with an absolute pressure of 50 kPa or less. As the cooling roll, a copper alloy roll (diameter: 350 mm) covered with a chromium plating layer having a thickness of 5 to 15 μm was used. While the copper alloy roll was rotated at a peripheral speed of 10 m / sec, the raw material alloy melt flowed down on the outer peripheral surface and rapidly solidified. The temperature of the molten metal was 1300 ° C. when measured with a radiation thermometer. The molten metal was dropped from the orifice to a diameter of 1.3 to 1.5 mm at a rate of 10 to 20 g per second.
[0097]
FIG. 4 is a graph showing how the coercive force and the residual magnetic flux density depend on the temperature of the crystallization heat treatment. In this graph, a black circle mark indicates a rapid solidification at a roll peripheral speed of 9 m / sec in an Ar atmosphere of 1.3 kPa (Example 1). In the case of rapid solidification (Example 2), white circles indicate data for the case of rapid solidification at a roll peripheral speed of 20 m / sec in a normal pressure Ar atmosphere (Comparative Example).
[0098]
As can be seen from FIG. 4, in Example 1 and Example 2, magnetic properties superior to those of the comparative example are obtained over a wide temperature range.
[0099]
FIG. 5 is a graph showing how the coercive force and the residual magnetic flux density depend on the throughput per unit time. In this graph, the black circle mark indicates that when rapidly solidified at a roll peripheral speed of 9 m / sec in an Ar atmosphere of 1.3 kPa (Example 1), the black square mark indicates that the roll peripheral speed is 20 m / second in an atmospheric pressure Ar atmosphere. The data for the case of rapid solidification in seconds (comparative example) are shown.
[0100]
As can be seen from FIG. 5, in Example 1, excellent magnetic properties were obtained with a larger throughput than in the comparative example.
[0101]
[Reason for composition limitation]
Finally, Fe _Three B / Nd ₂ Fe ₁₄ The reason for limiting the raw material alloy composition for the B-based nanocomposite magnet will be described.
[0102]
Rare earth element R is a hard magnetic phase R ₂ Fe ₁₄ It is an essential element for B. In the present invention, R contains 90 atom% or more of one or both of Pr and Nd, and the balance contains 0% or more and less than 10% of other lanthanum series elements or one or more elements of Y. One of the elements Pr and Nd is R having uniaxial crystal magnetic anisotropy. ₂ Fe ₁₄ Indispensable for producing B. Rare earth elements other than Pr and Nd are arbitrarily selected. If the composition ratio of R is less than 2 atomic%, the effect of generating a coercive force is too small, which is not preferable. On the other hand, when the composition ratio of R exceeds 6 atomic%, Fe _Three Phase B and Nd ₂ Fe ₁₄ Since the B phase is not generated and the α-Fe phase becomes the main phase, the coercive force is significantly reduced. From the above, the composition ratio x of R is preferably 2 ≦ x ≦ 6.
[0103]
B is Fe, which is a soft magnetic phase _Three B and R which are hard magnetic phases ₂ Fe ₁₄ It is an essential element for both B. When the composition ratio y of B is out of the range of 16 to 20 atomic%, the required coercive force is not exhibited. Therefore, the composition ratio y of B is preferably 16 ≦ y ≦ 20. Further, if B is out of this composition range, the melting point increases, the melting temperature and the temperature of the hot water storage container need to be increased, and the amorphous forming ability also decreases, so that it is difficult to obtain a desired quenched alloy structure. Become.
[0104]
Co has the function of reducing the temperature change dependency of the magnetic characteristics by increasing the Curie temperature, and as a result, stabilizing the magnetic characteristics. It also has the function of improving the viscosity of the molten alloy and contributes to the stabilization of the molten metal flow rate. When the addition ratio of Co is less than 0.02 atomic%, the above function is not fully exhibited, and when it exceeds 7 atomic%, the magnetization characteristics begin to deteriorate. Co may be added when it is desired to exert these functions, and addition of Co is not indispensable for obtaining the effects of the present invention. When Co is added, it is preferable that 0.2 ≦ z ≦ 7 holds for the composition ratio z for the reason described above.
[0105]
M is added when the coercive force is to be increased as much as possible. When the addition ratio of M is less than 0.01 atomic%, the coercive force increase is not sufficiently observed, and when the addition ratio of M exceeds 7 atomic%, the magnetization decreases. Therefore, when M is added, it is preferable that 0.1 ≦ z ≦ 7 holds for the composition ratio u. Among M, Cr exhibits an effect of improving corrosion resistance in addition to an increase in coercive force. Further, Cu, Au, and Ag have an effect of expanding the appropriate temperature range in the crystallization heat treatment step.
[0106]
[Method for producing Fe-based rapidly solidified alloy]
Even when an Fe-based rapidly solidified alloy is produced under normal pressure by the single roll method, the adhesion between the cooling roll and the alloy is lowered due to the entrainment of the atmospheric gas, and as a result, the cooling rate is inconsistent depending on the part of the alloy ribbon. Problems arise when uniform. Produces Fe-based rapidly solidified alloys that partially contain crystalline phases compared to producing all-crystalline alloy ribbons and Fe-based rapidly solidified alloys that are all substantially amorphous. In this case, it is necessary to control a relatively slow cooling rate within a predetermined range with high accuracy. In such a case, problems as shown in FIG. 1A may occur under normal pressure.
[0107]
Accordingly, the present invention provides the general formula Fe _100-xy R _x B _y , Fe _100-xyz R _x B _y Co _z , Fe _100-xyu R _x B _y M _u Or Fe _100-xyzu R _x B _y Co _z M _u When producing an Fe-based rapidly solidified alloy in which the crystalline phase is in a state of 10% or less of the whole, although it exhibits a remarkable effect when applied to a raw material alloy for a nanocomposite magnet represented by Also effective. Such an Fe-based rapidly solidified alloy is crystallized by a subsequent heat treatment, and a uniform metal structure can be expressed with good reproducibility. In addition, since the influence of entrainment tends to become significant when the peripheral speed of the cooling roll is reduced, it is difficult to reduce the peripheral speed of the roll in a normal pressure atmosphere. In general, the slower the roll peripheral speed, the slower the deterioration of the cooling roll. Therefore, according to the present invention, there is an advantage that the cooling roll can be used for a long period of time with high reliability.
[0108]
As the Fe-based rapidly solidified alloy here, for example, Nd ₁₃ Fe ₈₂ B _Five , Fe ₇₄ Cu ₁ Nb _Three Si ₁₆ B ₆ , Fe ₉₁ Zr ₇ B ₂ , Fe ₉₁ Hf ₇ B ₂ Etc. are included.
[0109]
【The invention's effect】
According to the present invention, since the adhesion between the cooling roll and the molten metal is improved by the reduced pressure atmosphere, uniform cooling is realized. Therefore, a desired metallic glass-like alloy is obtained, and the magnetic properties after heat treatment are improved. Fe _Three B / Nd ₂ Fe ₁₄ The result is that the crystallization reaction heat for forming the B-based nanocomposite magnet is dispersed in a wide temperature range, and the microcrystallization can be executed with good controllability without releasing the large crystallization reaction heat at once. The raw material powder throughput in the heat treatment step can be improved without deteriorating the magnet characteristics.
[0110]
Fe _Three Since the crystal nuclei necessary for crystallization of B are present in the raw material alloy at a high density and the Fe phase is small, a fine and uniform metal structure can be formed by magnetizing heat treatment, and high magnet properties can be exhibited. enable.
[Brief description of the drawings]
FIGS. 1A and 1B are schematic cross-sectional views of an alloy ribbon obtained when the above alloy is rapidly solidified in a normal pressure atmosphere using a one-roll method, and FIG. And (d) are drawings corresponding to (a) and (b), respectively, and are schematic cross-sectional views of alloy ribbons produced when rapid solidification is performed in a reduced-pressure atmosphere.
2A is a cross-sectional view showing an example of the overall configuration of an apparatus used in a method for producing a raw material alloy for a nanocomposite magnet according to the present invention, and FIG. 2B is an enlarged view of a portion where rapid solidification is performed. is there.
FIG. 3 is a cross-sectional view showing an example of a heat treatment apparatus used in a method for producing a nanocomposite magnet according to the present invention.
FIG. 4 is a graph showing how coercive force and residual magnetic flux density depend on the temperature of crystallization heat treatment.
FIG. 5 is a graph showing how coercive force and residual magnetic flux density depend on the throughput per unit time.
[Explanation of symbols]
1b, 2b, 8b, and 9b Atmospheric gas supply port
1a, 2a, 8a, and 9a gas outlet
1 Dissolution chamber
2 quenching room
3 Melting furnace
4 Hot water storage container
5 Hot water nozzle
6 funnel
7 Rotating cooling roll
10 Breaker 10
11 Compressor
21 Molten metal
22 Alloy ribbon
23 Alloy flakes
28 body
24 Rotating roll
25 Rotating roll
26 Hoop Belt
27 Scraper

Claims (12)

General formula _{Fe 100-xy R x B y} , is represented by _{Fe 100-xyz R x B y} Co z, Fe 100-xyu R x B y M u, or _{Fe 100-xyzu R x B y} Co z M u A raw material alloy for a nanocomposite magnet, wherein R contains 90 atomic% or more of one or both of Pr and Nd, and the balance is 0% or more and 10% of one or more elements of other lanthanum series elements or Y R is a rare earth element, and M is a group consisting of Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Hf, Ta, W, Pt, Pb, Au, and Ag. One or more elements selected from the group consisting of 2 ≦ x ≦ 6, 16 ≦ y ≦ 20, 0.2 ≦ z ≦ 7, and 0.01 ≦ u ≦ 7. In a method for producing a raw material alloy for a nanocomposite magnet satisfying
Including a step of rapidly solidifying the molten alloy of the raw material alloy by a liquid quenching method using a cooling roll,
During the rapid solidification step, rapid solidification of the alloy is performed in a reduced-pressure atmosphere, thereby producing a rapidly solidified alloy in a metallic glass state ,
By adjusting the cooling rate of the alloy, the raw alloy after solidification contains a metastable phase Z having a Bragg scattering peak at a position corresponding to a crystal plane interval of 0.179 nm ± 0.005 nm in X-ray diffraction. Moreover, the intensity of the Bragg scattering peak is 5% or more and less than 200% of the maximum intensity of the halo pattern in the X-ray diffraction, and the intensity of the (110) Bragg scattering peak of the body-centered cubic Fe is the halo pattern. A method for producing a raw material alloy for a nanocomposite magnet, characterized in that it is less than 5% of the maximum strength .   2. The method for producing a raw material alloy for a nanocomposite magnet according to claim 1, wherein an absolute pressure of the reduced-pressure atmosphere is 50 kPa or less.   The method for producing a raw material alloy for a nanocomposite magnet according to claim 1 or 2, further comprising a step of producing a powder from the rapidly solidified raw material alloy. In the rapid solidification step, the cooling rate of the alloy is set to 5 × 10 ^{4 to} 5 × 10 ⁶ K / second, and the temperature of the alloy is lowered to a temperature lower by 400 to 800 ° C. than the temperature Tm of the alloy before the rapid cooling. The manufacturing method of the raw material alloy for nano composite magnets as described in any one of 1-3. General formula _{Fe 100-xy R x B y} , is represented by _{Fe 100-xyz R x B y} Co z, Fe 100-xyu R x B y M u, or _{Fe 100-xyzu R x B y} Co z M u An alloy for nanocomposite magnets, wherein R contains 90 atomic% or more of one or both of Pr and Nd, and the balance is 0% or more and less than 10% of other lanthanum series elements or one or more elements of Y It is a rare earth element to be contained, and M is selected from the group consisting of Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Hf, Ta, W, Pt, Pb, Au, and Ag. One or more selected elements, the composition ratios x, y, z and u satisfy 2 ≦ x ≦ 6, 16 ≦ y ≦ 20, 0.2 ≦ z ≦ 7, and 0.01 ≦ u ≦ 7. A step of preparing a satisfactory raw material alloy powder for a nanocomposite magnet;
A process for producing a nanocomposite magnet powder comprising a step of heat-treating the powder of the raw material alloy for the nanocomposite magnet and thereby performing crystallization of the Fe ₃ B compound and the Fe—R—B compound. There,
The step of preparing the raw material alloy powder for the nanocomposite magnet,
A step of rapidly solidifying the molten alloy of the raw material alloy in a reduced pressure atmosphere by a liquid quenching method using a cooling roll to produce a rapidly solidified alloy in a metallic glass state;
Producing the powder from the rapidly solidified alloy;
It encompasses,
In the step of producing the rapidly solidified alloy, a metastable phase having a Bragg scattering peak at a position corresponding to a crystal plane interval of 0.179 nm ± 0.005 nm in X-ray diffraction by adjusting the cooling rate of the alloy. Z is contained in the raw material alloy after solidification, and the intensity of the Bragg scattering peak is 5% or more and less than 200% of the maximum intensity of the halo pattern in the X-ray diffraction, and (110 ) A method for producing a nanocomposite magnet powder, characterized in that the intensity of the Bragg scattering peak is less than 5% of the maximum intensity of the halo pattern .   6. The method for producing a nanocomposite magnet powder according to claim 5, wherein the absolute pressure of the reduced-pressure atmosphere is 50 kPa or less. In the rapid solidification step, the cooling rate of the alloy is set to 5 × 10 ^{4 to} 5 × 10 ⁶ K / second, and the temperature of the alloy is lowered to a temperature lower by 400 to 800 ° C. than the temperature Tm of the alloy before the rapid cooling. A method for producing a nanocomposite magnet powder according to 5 or 6. General formula _{Fe 100-xy R x B y} , is represented by _{Fe 100-xyz R x B y} Co z, Fe 100-xyu R x B y M u, or _{Fe 100-xyzu R x B y} Co z M u An alloy for nanocomposite magnets, wherein R contains 90 atomic% or more of one or both of Pr and Nd, and the balance is 0% or more and less than 10% of other lanthanum series elements or one or more elements of Y It is a rare earth element to be contained, and M is selected from the group consisting of Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Hf, Ta, W, Pt, Pb, Au, and Ag. One or more selected elements, and the composition ratios x, y, z and u are 2 ≦ x ≦ 6, 16 ≦ y ≦ 20, 0.2 ≦ z ≦ 7.0, 0.01 ≦ u ≦ 7 Preparing a raw material alloy powder for a nanocomposite magnet satisfying
Performing a heat treatment on the powder of the raw material alloy for the nanocomposite magnet, thereby performing crystallization of the Fe ₃ B compound and the Fe—R—B-based compound;
A method of producing a nanocomposite magnet comprising a step of forming a molded body using the raw material alloy powder after the heat treatment,
The step of preparing the raw material alloy powder for the nanocomposite magnet,
A step of rapidly solidifying the molten alloy of the raw material alloy in a reduced pressure atmosphere by a liquid quenching method using a cooling roll;
Including the step of producing the powder from the rapidly solidified raw material alloy ,
In the step of rapidly solidifying the molten alloy of the raw material alloy, by adjusting the cooling rate of the alloy, a quasi-quad having a Bragg scattering peak at a position corresponding to a crystal plane interval of 0.179 nm ± 0.005 nm in X-ray diffraction. The raw material alloy after solidification contains the stable phase Z, and the intensity of the Bragg scattering peak is 5% or more and less than 200% of the maximum intensity of the halo pattern in the X-ray diffraction. (110) A method for producing a nanocomposite magnet, wherein the intensity of the Bragg scattering peak is less than 5% of the maximum intensity of the halo pattern .   The method for producing a nanocomposite magnet according to claim 8, wherein an absolute pressure of the reduced-pressure atmosphere is 50 kPa or less. In the rapid solidification step, the cooling rate of the alloy is set to 5 × 10 ^{4 to} 5 × 10 ⁶ K / second, and the temperature of the alloy is lowered to a temperature lower by 400 to 800 ° C. than the temperature Tm of the alloy before the rapid cooling. The method for producing a nanocomposite magnet according to 8 or 9.   The method for producing a nanocomposite magnet according to any one of claims 8 to 10, wherein the step of forming the formed body includes a step of producing a bonded magnet using the raw material alloy powder after the heat treatment.   The motor provided with the nanocomposite magnet manufactured by the manufacturing method of the nanocomposite magnet as described in any one of Claims 8-11.

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