JP2018107446A - Rare earth permanent magnet material and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rare earth permanent magnet material and a manufacturing method thereof.SOLUTION: A raw material for forming a rare earth permanent magnet material contains an A component of which the main phase is RFeMB(wherein R is Nd or PrNd and it leads 27≤x≤34, 0.3≤y≤5 and 0.7≤z≤1.1) and a B component of which the main phase is YFeMB(wherein it leads 25≤a≤30, 0≤b≤1.5 and 1.2≤c≤3 and M is one or more kinds selected from among Al, Co, Cu and Ga). All contents of elements are weight contents. The rare earth permanent magnet material much further reduces a temperature coefficient of a rare earth permanent magnet material that is obtained by mixing the B component containing Y and an ordinary Nd(Pr)FeB rare earth permanent magnet material, further improves heat resistance and does not contain heavy rare earth elements, such that the cost is relatively low.SELECTED DRAWING: Figure 1

Description

  The present invention relates to the field of rare earth materials, and specifically to a rare earth permanent magnet material and a method for manufacturing the same.

Rare earth permanent magnet materials are irreplaceable basic materials in many fields as materials for supplying energy, and are widely used in many fields such as electronics, automobiles, computers, and the development of various industries. Promotes. With the development of science and technology, there is an increasing demand for the performance of materials in order to satisfy the requirements of special fields such as high magnetism and high temperature and to promote the evolution of parts to which they are applied.

  Among the manufacturing methods of rare earth permanent magnet materials, the heat treatment method is a method for manufacturing high dimensional accuracy and high performance permanent magnet materials, and the main manufacturing process is to manufacture permanent magnet powder at a certain temperature. Pressurizing to form a compression molded body, and thermally deforming the compression molded body to form a heat-deformed magnet. In terms of the entire manufacturing process, permanent magnet powder, hot pressing, thermal deformation process, etc. all have a very important influence on the performance of the final product. Many improvements are currently submitted for each process to further improve the performance of the final magnet. For example, in the patent document with the publication number CN104143402A, a heat-deformed magnet raw material based on PrGaBFe for improving the residual magnetic flux density and coercive force of the magnet and setting its orientation degree to 0.92 is submitted. . In the patent document whose publication number is CN104078179A, the NdFe raw material powder B is subjected to heavy rare earth element RH precipitation treatment, and the heavy rare earth element is adhered to the powder surface, thereby improving the final magnet coercive force and using heavy rare earth elements. A method of manufacturing a heat-deformed magnet that reduces the amount is disclosed. Patent document No. CN104043834A discloses that NdFe raw material powder B is mixed with powder containing Tb and Dy, and the mixed powder is hot pressed to be thermally deformed. In the patent document whose publication number is CN102436890A, rare earth fluoride, hydride powder and nanocrystalline NdFeB magnet powder are mixed, hot pressed and thermally deformed, and the particles of rare earth fluoride or hydride to NdFeB magnet powder are mixed. A method for producing a nanocrystalline NdFeB permanent magnet material that obtains a powder having a high coercivity by diffusion into the field is disclosed. The patent document whose publication number is CN102496437A discloses a method for producing each anisotropic nanocomposite magnet having a volume fraction of the soft magnetic phase of 2 to 40%, and by this method, the residual magnetic flux of the permanent magnet material is disclosed. Further improving the density and magnetic energy product is disclosed.

  In the published patent document, the performance of the magnet is improved by modifying the final high-density magnet from various viewpoints such as components and manufacturing processes. However, as the field of use is expanding, in the field of automobile EPS motors and the like, the demand for heat resistance of the magnet is increasing, and in the conventional method such as the method of adding heavy rare earth element Dy to the magnet and the grain boundary diffusion method, In any case, the use of Dy is essential, and a method for forming a medium heavy rare earth-free heat-treated rare earth permanent magnet is required.

  The main object of the present invention is to provide a rare earth permanent magnet material and a method for producing the same, and to solve the problem of high cost because rare earth permanent magnet powder uses heavy rare earth elements in the prior art.

To achieve the above object, in one aspect of the present invention, the raw material for forming a rare earth permanent magnet materials, in the main phase _{R x Fe 100-xy M y} B z ( wherein, R is Nd or PrNd A component that is 27 ≦ x ≦ 34, 0.3 ≦ y ≦ 5, 0.7 ≦ z ≦ 1.1) and the main phase is Y _a Fe _100-abc M _b B _c (wherein 25 ≦ a ≦ 30, 0 ≦ b ≦ 1.5, 1.2 ≦ c ≦ 3, and M is one or more selected from Al, Co, Cu, and Ga), and the content of each of the above elements is the weight content. A rare earth permanent magnet material is provided.

  Furthermore, the weight ratio of the A component to the B component is 3 to 5: 1.

In other aspects of the present invention, the main phase quenching ribbon A and the main phase of the A component is a _{R x Fe 100-xy M y} B z is _{Y a Fe 100-abc M b} B c quenched ribbon B component Step S1 for producing B (wherein R is Nd or PrNd, 27 ≦ x ≦ 34, 0.3 ≦ y ≦ 5, 0.7 ≦ z ≦ 1.1, 25 ≦ a ≦ 30, 0 ≦ b ≦ 1.5, 1.2 ≦ c ≦ 3, M is one or more selected from Al, Co, Cu, Ga, and the content of each of the above elements is the weight content), and the quenching ribbon A and the quenching ribbon B are pulverized Then, there is provided a method for producing a rare earth permanent magnet material, comprising: mixing step S2 to obtain a mixed powder; and step S3 obtaining a rare earth permanent magnet material by heat-treating the mixed powder.

  Furthermore, the weight ratio of the quenching ribbon A and the quenching ribbon B is 3 to 5: 1.

  Furthermore, the thicknesses of the quenching ribbon A and the quenching ribbon B are independently controlled to 10 to 150 μm, and preferably, in step S1, the first roll speed for producing the quenching ribbon A produces the quenching ribbon B. Less than the second roll speed.

  Further, the first roll speed and the second roll speed are 15 to 55 m / s, and preferably the ratio of the second roll speed and the first roll speed is 1.1 to 1.6: 1.

  Further, in step S1, the raw material A is melted in a temperature range that is 100 to 300 ° C. higher than the melting point of the raw material A that produces the quenching ribbon A, and the temperature range that is 100 to 300 ° C. higher than the melting point of the raw material B that produces the quenching ribbon B To melt raw material B.

  Further, the step S2 pulverizes the quenching ribbon A and the quenching ribbon B to obtain powder A and powder B, preferably the average particle size of powder A and powder B is 100 to 250 μm, and powder A And mixing powder B to obtain a mixed powder.

  Furthermore, step S3 includes a step of compressing the mixed powder in one direction at a temperature of 450 ° C. or higher and lower than 800 ° C.

  Furthermore, the above step S3 hot-presses the mixed powder to obtain a magnet, the temperature of the hot press is preferably 650 to 750 ° C., the pressure is preferably 100 to 300 MPa, and the magnet is thermally deformed. A rare earth permanent magnet material is obtained, and the temperature of heat deformation is preferably 750 to 900 ° C., the pressure is preferably 100 to 200 MPa, and the heat deformation rate is preferably 0.1 to 0.8 mm / s. .

  According to the present invention, the rare earth permanent magnet material has a lower temperature coefficient of the rare earth permanent magnet material obtained by mixing the B component containing Y and the normal Nd (Pr) FeB rare earth permanent magnet material, and has high heat resistance. The cost is relatively low because it is superior and does not contain heavy rare earth elements.

  The drawings, which form part of this application, are intended to provide a further understanding of the invention, and the exemplary embodiments of the invention and the description thereof are intended to interpret the invention. It is not limited. In the drawing

FIG. 1 is a chart showing a manufacturing process of a rare earth permanent magnet material provided in one preferred embodiment of the present invention. FIG. 2 is a view showing the structure of the hot press mold before hot pressing in one preferred embodiment of the present invention. FIG. 3 is a view showing a structure after hot pressing of the hot press mold shown in FIG. FIG. 4 is a view showing the structure before hot pressing of the heat deformation mold provided in one preferred embodiment of the present invention. FIG. 5 is a view showing a structure after thermal deformation of the thermal deformation mold shown in FIG.

  As long as there is no contradiction, it is understood that the embodiment in the present application and the requirements in the embodiment can be combined. Hereinafter, the present invention will be described in detail with reference to the drawings and examples.

  As described in the background art, in the prior art, in order to improve the performance of the magnet, the use of all heavy rare earth elements such as Dy is unavoidable, resulting in an increase in cost. In order to solve this problem, the present invention provides a rare earth permanent magnet material and a manufacturing method thereof.

In one exemplary embodiment of the present invention, the raw material for forming a rare earth permanent magnet material, the main phase _{R x Fe 100-xy M y} B z ( wherein, R is Nd or PRND, 27 ≦ x ≦ 34, 0.3 ≦ y ≦ 5, 0.7 ≦ z ≦ 1.1) and the main phase is Y _a Fe _100-abc M _b B _c (where 25 ≦ a ≦ 30, 0 ≦ b ≦ 1.5, 1.2 ≦ c ≦ 3, where M is one or more selected from Al, Co, Cu, and Ga) and the content of each of the above elements is a rare earth permanent Provide magnet material.

  The rare earth permanent magnet material of the present invention has a much lower temperature coefficient of the rare earth permanent magnet material obtained by mixing the B component containing Y and a normal Nd (Pr) FeB rare earth permanent magnet material, and is more heat resistant. The cost is relatively low because it is excellent and does not contain heavy rare earth elements.

  In order to further control the temperature coefficient and heat resistance of the rare earth permanent magnet material, the weight ratio of the A component to the B component is preferably 3 to 5: 1.

In another exemplary embodiment of the present invention, the A component quenching ribbon A whose main phase is R _x Fe _100-xy M _y B _z and the main phase is Y _a Fe _100-abc M _b B _c Step S1 for producing B component quenching ribbon B (wherein R is Nd or PrNd, 27 ≦ x ≦ 34, 0.3 ≦ y ≦ 5, 0.7 ≦ z ≦ 1.1, 25 ≦ a ≦ 30, 0 ≦ b) ≦ 1.5, 1.2 ≦ c ≦ 3, M is one or more selected from Al, Co, Cu, and Ga, and the content of each of the above elements is a weight content), and the quenching ribbon A and There is provided a rare earth permanent magnet material production method including step S2 of pulverizing and mixing the quenched ribbon B to obtain a mixed powder, and step S3 of obtaining a rare earth permanent magnet material by heat treating the mixed powder.

  In the present invention, by mixing a quenching ribbon containing Y and a normal Nd (Pr) Fe quenching ribbon B, it is possible to obtain a mixed powder having a much lower temperature coefficient and better heat resistance, By conducting the heat treatment, an anisotropic rare earth permanent magnet can be obtained at a high density.

  With the quenching ribbon, a molten alloy solution having a certain component is injected into a rotating roll through a nozzle, the molten alloy liquid becomes a liquid film on the surface of the roll, and is taken out at a high speed, rapidly cooled, It is the quenching ribbon obtained.

  In order to further control the temperature coefficient and heat resistance of the rare earth permanent magnet material, the weight ratio of the quenching ribbon A and the quenching ribbon B is preferably 3 to 5: 1.

  In one preferred embodiment of the present invention, the thickness of the quench ribbon A and the quench ribbon B is independently controlled to 10 to 150 μm. If the quenching ribbon is too thin, the manufacturing conditions become severe. However, if the quenching ribbon is too thick, the production of the magnet in a subsequent heat treatment is hindered, so the above thickness range is preferable.

  In order to mix the quenching ribbon better and uniformly and to contribute to the subsequent uniform hot press thermal deformation process of the mixed powder, in step S1, the first roll speed for producing the quenching ribbon A is the quenching ribbon B. It is preferable that the speed is smaller than the second roll speed at which is manufactured. Further, the thickness of the quenching ribbon A is made larger than the thickness of the quenching ribbon B by controlling the first roll speed and the second roll speed.

  Based on the thickness, the composition of the raw material A that forms the quenching ribbon A, and the composition of the raw material B that forms the quenching ribbon B, the first roll speed and the second roll are determined by a plurality of tests. It could be specified that the speed is preferably 15 to 55 m / s. Furthermore, in order to control the difference between the thickness of the quenching ribbon A and the thickness of the quenching ribbon B, the ratio of the second roll speed to the first roll speed is preferably 1.1 to 1.6: 1.

  When manufacturing a rapidly cooled ribbon, the melting temperature of the raw material may be referred to a conventional technique. In the present invention, in step S1, the raw material A is melted in a temperature range 100 to 300 ° C. higher than the melting point of the raw material A for producing the quenching ribbon A, and the temperature 100 to 300 ° C. higher than the melting point of the raw material B for producing the quenching ribbon B It is preferable to melt the raw material B within the range. This makes it possible to achieve quick melting and avoid high energy consumption due to the melting temperature being too high.

  Since the quenching ribbon A and the quenching ribbon B obtained in step S1 of the present invention can have different thicknesses, in order to ensure a mixing effect, the above step S2 is performed by pulverizing the quenching ribbon A and the quenching ribbon B to obtain a powder A And powder B, preferably the average particle size of powder A and powder B is 100 to 250 μm, and mixing powder A and powder B to obtain a mixed powder is preferable. By pulverizing the quenching ribbon A and the quenching ribbon B, the particle sizes of the two kinds of powders can be controlled within a predetermined range. The pulverization method includes compression pulverization, airflow pulverization, and pulverization with a cutter.

  Further, in order to optimize the anisotropy and denseness of the rare earth permanent magnet material, the step S3 preferably includes a step of compressing the mixed powder in one direction at a temperature of 450 ° C. or higher and lower than 800 ° C.

  In another preferred embodiment of the present invention, the step S3 includes hot pressing the mixed powder to obtain a magnet, and thermally deforming the magnet to obtain a rare earth permanent magnet material. After hot pressing the mixed powder, the mixed powder is densified to form a hot pressed magnet close to true density, and then thermally deformed, thereby further improving the thermal characteristics of the hot pressed magnetism.

  The said hot press process is performed with a hot press metal mold | die. As shown in FIG. 2, the mold is divided into a first female mold 201 and a first male mold 202, and the mold is put into a first heating body 205 which is a heating body by induction heating body or hot wire, The mixed powder 203 is put in the first female mold 201, the first heating body 205 is turned on, the mold and the mixed powder therein are heated, and the first male mold 202 is moved downward. The powder was hot pressed to obtain a rare earth permanent magnet 204 (ρ> 98%) having the true density shown in FIG. Regarding the composition of the mixed powder, the temperature of the hot press is preferably 650 to 750 ° C. and the pressure is preferably 100 to 300 MPa in order to make the whole magnet uniform and improve the performance thereafter.

  The heat deformation step is performed with a heat deformation mold. As shown in FIG. 4, the thermal deformation mold includes a second female mold 1001 and a second male mold 1002. For magnets having different shapes, the mold design is also different. Here, a square magnet is illustrated as a design example. As shown in FIG. 4, the inner diameter of the second female mold 1001 and the outer diameter of the second male mold 1002 are both larger than the mold shown in FIG. The rare earth permanent magnet 204 manufactured in FIG. 3 is placed inside the second female mold 1001, and then the entire mold system is heated by the second heating body 1003, and at the same time the second male mold 1002 is lowered. Then, after the rare earth permanent magnet stone 204 was thermally deformed and cooled, a square magnet 1005 shown in FIG. 5 was obtained.

  In order to obtain a heat-deformed magnet having high performance, the temperature of the heat deformation is preferably 750 to 900 ° C., the pressure is preferably 100 to 200 MPa, and the heat deformation rate is preferably 0.1 to 0.8 mm / s. is there.

  The advantageous effects of the present invention will be further described below with reference to examples and comparative examples.

  The performance of the high-density anisotropic magnet obtained in each example is measured by the following method.

  In the performance test, the magnetic performance is mainly measured by a permanent magnet measuring instrument. The measurement data includes a residual magnetic flux density Br having a unit of kGs, a coercive force Hcj having a unit of kOe, and a magnetic energy product (BH) m having a unit of MGOe. The temperature coefficient measurement is performed according to GB / T 24270-2009, and in the present invention, it means the coercivity temperature coefficient β.

  As shown in FIG. 1, the manufacturing process is specifically as follows.

  <Quenching ribbon>

Raw material A and raw material B were prepared. The raw material components A is _{R x Fe 100-xy M y} B z, components of the raw material B is _{Y a Fe 100-abc M b} B c, the specific chemical composition is shown in Table 1. The prepared raw material was put into a heating container, the raw material was melted by an induction coil, and then injected through the nozzle onto the surface of a rotating cooling roll, and a rapid cooling ribbon was obtained by roll rotation. Table 1 shows the melting temperature, roll speed, and thickness of the obtained rapid cooling ribbon when manufacturing the rapid cooling ribbon A and the rapid cooling ribbon B.

  <Mixed>

  The manufactured quenched ribbon was roughly pulverized and then mixed to obtain a mixed powder. In the examples, the particle size after pulverization is 40 mesh, the two kinds of pulverized powders are mixed at a constant ratio, and the mixing weight ratio σ of the quenching ribbon A and the quenching ribbon B is shown in Table 2.

  In the comparative example, the content of the powder containing Y is 0.

  <Heat treatment>

  The mixed powder was put into a mold and heat treated to obtain a high density anisotropic magnet. The hot press is performed with the mold shown in FIG. 2, and the thermal deformation is performed with the mold shown in FIG. 4.In the hot press step, the temperature is T1, the pressure is P1, and in the thermal deformation step, the temperature and The pressure is T2 and P2, respectively. Specific process parameters are shown in Table 2.

  Table 1 (bal represents the balance)

  Table 2

  As can be seen from the comparison between Example 1, Example 2 and Comparative Example 1 and Comparative Example 2 in the above table, the magnetic performance is not significantly reduced after adding the B component containing a certain amount of Y in this method. On the premise, the coercive force temperature coefficient β was significantly improved. Therefore, when the temperature is increased, the coercive force of the thermally deformable material can be largely maintained, and the utilization of the thermally deformable material at a high temperature is promoted.

  Further, as is clear from Table 1, the influence of the production process of the two types of components A and B is also remarkable, and particularly regarding the rapid cooling rate of both, component B is compared with Example 1 and Example 10. When the quenching roll speed at the time of manufacture was higher than the quenching roll speed at the time of manufacture of component A, the effect was more excellent. Further, as can be seen from the comparison between Example 5 and Example 9, when the difference between the two speeds is too large (≧ 1.5), it is disadvantageous for improving the performance.

  From the above description, it can be seen that the above-described embodiment of the present invention can realize the following effects.

  The rare earth permanent magnet material of the present invention has a much lower temperature coefficient of the rare earth permanent magnet material obtained by mixing the B component containing Y and a normal Nd (Pr) FeB rare earth permanent magnet material, and is more heat resistant. The cost is relatively low because it is excellent and does not contain heavy rare earth elements.

  By mixing the quenching ribbon containing Y and the normal Nd (Pr) Fe quenching ribbon B, it is possible to obtain a mixed powder with a lower temperature coefficient and better heat resistance, and further heat treatment Thus, an anisotropic rare earth permanent magnet with high density can be obtained.

  The above are only preferred embodiments of the present invention, and the present invention is not limited thereto. Those skilled in the art will appreciate that various changes and modifications can be made to the present invention. Various modifications, substitutions, improvements, and the like are all encompassed by the present invention without departing from the spirit and scope of the present invention.

Claims (10)

Raw materials for forming rare earth permanent magnet materials are:
A component in which the main phase is R _x Fe _100-xy M _y B _z (wherein R is Nd or PrNd, 27 ≦ x ≦ 34, 0.3 ≦ y ≦ 5, 0.7 ≦ z ≦ 1.1), The phase is Y _a Fe _100-abc M _b B _c (wherein 25 ≦ a ≦ 30, 0 ≦ b ≦ 1.5, 1.2 ≦ c ≦ 3, M is one selected from Al, Co, Cu, Ga or A rare earth permanent magnet material comprising a plurality of types of B component, wherein the content of each element is a weight content.   2. The rare earth permanent magnet material according to claim 1, wherein a weight ratio of the A component to the B component is 3 to 5: 1. Main phase steps S1 to quench ribbon A and the main phase of the A component is a _{R x Fe 100-xy M y} B z to produce a Y _a Fe _100-abc M _b quenched ribbon B of the B component is a B _c ( In the formula, R is Nd or PrNd, 27 ≦ x ≦ 34, 0.3 ≦ y ≦ 5, 0.7 ≦ z ≦ 1.1, 25 ≦ a ≦ 30, 0 ≦ b ≦ 1.5, 1.2 ≦ c ≦ 3, M is Al , Co, Cu, Ga, or one or more selected from the above, and the content of each element is a weight content)
Step S2 for obtaining a mixed powder by pulverizing and mixing the quenching ribbon A and the quenching ribbon B, and
And step S3 of obtaining the rare earth permanent magnet material by heat-treating the mixed powder.   4. The manufacturing method according to claim 3, wherein a weight ratio of the quenching ribbon A and the quenching ribbon B is 3 to 5: 1.   The thicknesses of the quenching ribbon A and the quenching ribbon B are independently controlled to 10 to 150 μm, and preferably, in the step S1, the first roll speed for producing the quenching ribbon A is the quenching ribbon B. 4. The production method according to claim 3, wherein the production speed is smaller than a second roll speed to be produced.   The first roll speed and the second roll speed are 15 to 55 m / s, preferably the ratio of the second roll speed and the first roll speed is 1.1 to 1.6: 1. 6. The manufacturing method according to claim 5, wherein the manufacturing method is characterized.   In step S1, the raw material A is melted in a temperature range 100 to 300 ° C. higher than the melting point of the raw material A for producing the quenching ribbon A, and the temperature is 100 to 300 ° C. higher than the melting point of the raw material B for producing the quenching ribbon B 4. The production method according to claim 3, wherein the raw material B is melted in a range. Step S2 includes
The quenched ribbon A and the quenched ribbon B are pulverized to obtain powder A and powder B, preferably the average particle diameter of the powder A and the powder B is 100 to 250 μm, and
4. The production method according to claim 3, comprising mixing the powder A and the powder B to obtain the mixed powder.   4. The manufacturing method according to claim 3, wherein the step S3 includes a step of compressing the mixed powder in one direction at a temperature of 450 ° C. or higher and lower than 800 ° C. Step S3 includes
The mixed powder is hot pressed to obtain a magnet, the temperature of the hot press is preferably 650 to 750 ° C., and the pressure is preferably 100 to 300 MPa, and
The magnet is thermally deformed to obtain the rare earth permanent magnet material, the temperature of the heat deformation is preferably 750 to 900 ° C., the pressure is preferably 100 to 200 MPa, and the heat deformation rate is preferably 0.1 to 0.8 mm. 9. The production method according to claim 8, comprising / s.