JP5757234B2 - Method for producing quench ribbon for rare earth magnet - Google Patents

Description

  The present invention relates to a method for producing a quenched ribbon for a rare earth magnet.

  Rare earth magnets using rare earth elements such as lanthanoids are also called permanent magnets, and their uses are used in motors for driving hard disks and MRI, as well as drive motors for hybrid vehicles and electric vehicles.

  Residual magnetization (residual magnetic flux density) and coercive force can be cited as indicators of the magnet performance of this rare earth magnet. However, in response to increased heat generation due to miniaturization of motors and higher current density, rare earth magnets used also The demand for heat resistance is further increasing, and how to maintain the coercive force of a magnet under high temperature use is one of the important research subjects in the technical field. Taking Nd-Fe-B magnets, one of the rare-earth magnets frequently used in vehicle drive motors, to refine crystal grains, use a composition alloy with a large amount of Nd, Attempts have been made to increase the coercivity by adding heavy rare earth elements such as high Dy and Tb.

  As rare earth magnets, in addition to general sintered magnets with a crystal grain (main phase) scale of 3 to 5 μm constituting the structure, nanocrystal magnets with crystal grains refined to a nanoscale of about 50 nm to 300 nm are available. Among them, nanocrystal magnets that can reduce the amount of expensive heavy rare earth elements added (free) while miniaturizing the crystal grains described above are currently attracting attention.

  An outline of a method for producing a rare earth magnet is as follows. For example, a rapidly cooled ribbon (quenched ribbon) obtained by rapidly solidifying a Nd-Fe-B metal melt is cut into a desired size to obtain a magnet powder. The powder is sintered while being pressed to produce a sintered body. In the case of a nanocrystal magnet, the sintered body is further subjected to hot plastic processing for imparting magnetic anisotropy to produce a molded body.

  A rare earth magnet with enhanced coercive force performance can be produced by applying a heavy rare earth element having high coercive force performance to the formed body by various methods. A manufacturing method can be mentioned.

  First, Patent Document 1 discloses a manufacturing method in which an evaporating material containing at least one of Dy and Tb is evaporated from a molded body subjected to hot plastic working, and grain boundaries are diffused from the surface of the molded body.

  This manufacturing method requires a high-temperature treatment of about 850 to 1050 ° C. in the process of evaporating the evaporation material, and this temperature range is specified from the improvement of the residual magnetic flux density and the suppression of crystal grain growth. It is assumed.

  However, when heat treatment is performed in a temperature range of about 850 to 1050 ° C., the crystal grains become coarse, and as a result, the coercive force is likely to be reduced. That is, while Dy and Tb are diffused at the grain boundaries, the coercive force cannot be sufficiently increased as a result.

  On the other hand, in Patent Document 2, at least one element of Dy, Tb, and Ho, or these and at least one of Cu, Al, Ga, Ge, Sn, In, Si, P, and Co is formed on the surface of the rare earth magnet. A manufacturing method is disclosed in which an alloy of elements is brought into contact and subjected to heat treatment so that the crystal grain size does not exceed 1 μm to diffuse grain boundaries.

  Here, in patent document 2, when the temperature at the time of heat processing is the range of 500-800 degreeC, it is excellent in the balance of the diffusion effect to the grain boundary phase, such as Dy, and the coarsening suppression effect of the crystal grain by heat processing, and high maintenance. It is said that it will be easier to obtain magnetic rare earth magnets. The various examples disclosed are heat-treated at 500 to 900 ° C. using a Dy-Cu alloy. Among various examples, the melting point of a typical 85Dy-15Cu alloy is 1100 ° C. Therefore, when trying to diffuse and infiltrate this molten metal, high temperature treatment of about 1000 ° C. or higher is required, and as a result, coarsening of crystal grains cannot be suppressed.

  In view of these various situations (Dy, etc. are expensive, coarsening of crystal grains in a high-temperature atmosphere when a modified alloy containing a high melting point heavy rare earth element is diffused into the grain boundary phase, etc.) The inventors use a modified alloy (modified phase) that does not use heavy rare earth metals such as Dy and Tb, and applies this modified alloy to the quenched ribbon to improve the coercive force performance of the quenched ribbon. The manufacturing method has been invented.

  By the way, the quenching ribbon for rare earth magnets is a thin and thin strip having a thickness of about 20 to 30 μm and a plane dimension of about 1 to 2 mm × several mm. Quality alloy quench ribbon is used. A quenched ribbon of a modified alloy is placed on the surface of a quenched ribbon for a rare earth magnet, heat treated to melt the quenched ribbon of the modified alloy, and diffused and permeated into the quenched ribbon precursor for the rare earth magnet. Yes.

  However, in this manufacturing method, the modified alloy in a liquid phase easily flows down from the quenching ribbon for the rare earth magnet, and only a part of the reformed alloy diffuses and penetrates into the quenching ribbon for the rare earth magnet. The problem that the coercive force of the quenching ribbon for the rare earth magnet cannot be sufficiently increased and the modified alloy is misaligned on the surface of the quenching ribbon for the rare earth magnet during heat treatment of the modified alloy, and the modified alloy becomes The present inventors have identified a problem that the coercive force is greatly different between an existing location and a non-existing location.

JP 2011-035001 A JP 2010-114200 A

  The present invention has been made in view of the above-mentioned problems, and does not use heavy rare earth metals such as Dy and Tb, and has a lower coercive force (particularly, a coercive force in a high temperature atmosphere) than a conventional method for producing rare earth magnets. It is an object of the present invention to provide a method for producing a quenching ribbon for a rare earth magnet capable of effectively diffusing and infiltrating a modified alloy for increasing the magnetic force into a quenching ribbon precursor for a rare earth magnet without waste.

  In order to achieve the above object, a method for producing a quenched ribbon for a rare earth magnet according to the present invention includes a RE-Fe-B main phase (at least one of RE: Nd and Pr) and an RE around the main phase. -X alloy (X: a metal element that does not contain heavy rare earth elements) is melted and injected into a rotating roll having a roll surface with a predetermined surface roughness. A first step of producing a quenched ribbon precursor for a rare earth magnet having the surface roughness transferred to one side thereof; a modified alloy on the surface having the surface roughness of the quenched ribbon precursor for the rare earth magnet; RE-Y alloy (Y: a metal element, not containing heavy rare earth elements) is contacted and heat-treated at a temperature equal to or higher than the melting point of the RE-Y alloy while both are pressurized. Rapid melting for rare earth magnets by diffusing and infiltrating Y alloy melt into quench ribbon precursor for rare earth magnets It consists of a second step of manufacturing a ribbon.

  The method for producing a quenching ribbon for rare earth magnets according to the present invention comprises a quenching ribbon of a modified alloy not using heavy rare earth metals such as Dy and Tb diffused and permeated into a quenching ribbon precursor for a rare earth magnet to quench the quenching ribbon for a rare earth magnet. Is to be manufactured. The surface of the quenched ribbon precursor for the rare earth magnet is provided with a predetermined surface roughness (unevenness), the modified alloy quenched ribbon is brought into contact with the side having the surface roughness, and both are pressurized. Thus, the quenched ribbon of the modified alloy is inserted into the surface irregularity of the quenched ribbon precursor for the relatively hard rare earth magnet while being deformed, so that the quenched ribbon of the modified alloy is inserted into the rare earth magnet. Therefore, it is possible to make the quenched ribbon of the modified alloy in close contact with the entire surface of the surface of the quenched ribbon precursor. By melting the reformed alloy quench ribbon in this state, the melted reformed alloy can be diffused and permeated throughout the quenching ribbon precursor for the rare earth magnet, and the generation of unnecessary reformed alloys can be eliminated. Is something that can be done.

  Here, as a method of forming a predetermined surface roughness on one side surface of the quenched ribbon precursor for a rare earth magnet, when injecting a molten alloy ingot to a rotating roll having a roll surface with a predetermined surface roughness, By providing a predetermined surface roughness on the roll surface in advance, a method of transferring the surface roughness of the roll surface to one side of the quenching ribbon when the molten alloy ingot is sprayed on one side and cured. be able to. It has been specified by the present inventors that the surface roughness provided on the roll surface is transferred as it is to the surface of the quenched ribbon precursor for the rare earth magnet to be formed.

  In this specification, “surface roughness” means centerline average roughness (Ra), a roughness curve is folded back from the centerline, and the area obtained by the roughness curve and the centerline is expressed as follows. The value divided by the length is expressed in micrometers.

  Here, as a preferred embodiment of a method for producing a quenched ribbon for a rare earth magnet according to the present invention, in the first step, in addition to producing a quenched ribbon precursor for a rare earth magnet, The alloy ingot is melted and sprayed onto a rotating roll having a roll surface with a predetermined surface roughness, thereby producing a rapidly cooled ribbon of a modified alloy in which the surface roughness of the roll surface is transferred to one side surface thereof. In the second step, a form in which the surfaces having the surface roughness of the quenched ribbon precursor for the rare earth magnet and the quenched ribbon of the modified alloy are brought into contact with each other and pressed can be exemplified.

  According to this embodiment, the unevenness on the surface of the quenched ribbon precursor for the rare earth magnet and the unevenness on the surface of the quenched ribbon of the modified alloy mesh with each other, and the adhesion between the two can be further enhanced.

  The surface roughness is preferably in the range of Ra = 0.05 μm to 5 μm.

  First, it is preferable that the surface roughness Ra is as small as possible because the surface of the quenched ribbon is cooled uniformly. However, when Ra is 0.04 μm or less, the inventors have specified that the surface of the quenched ribbon precursor for the rare earth magnet and the quenched ribbon of the modified alloy do not adhere to each other, and the quenched ribbons are separated from each other. Therefore, 0.04 μm or less is not preferable.

  From these, Ra = 0.05 μm is defined as the lower limit.

  On the other hand, if Ra exceeds 5 μm, the adhesiveness between the melted raw material and the roll surface of the rotating roll deteriorates during the rapid cooling when the rapid cooling ribbon is produced, and this decreases the rapid cooling rate, resulting in the generation of coarse particles. It has also been specified by the present inventors. From this, Ra = 5 μm is defined as the upper limit value of the preferable range of the surface roughness.

  The RE-X alloy that constitutes the grain boundary phase of the quenched ribbon precursor for rare earth magnets differs depending on the main phase component, but when RE is Nd, Nd, Co, Fe, Ga, Cu, Al For example, Nd—Co, Nd—Fe, Nd—Ga, Nd—Co—Fe, Nd—Co—Fe—Ga, or any of these It is a mixture of two or more types and is in an Nd rich state. When RE is Pr, the state is Pr-rich like Nd.

  In the above manufacturing method, since the RE-Y alloy, which is a modified alloy of the grain boundary phase, uses an alloy that does not contain heavy rare earth elements such as Dy and Tb, the melting point thereof is remarkably reduced as compared to Dy alloys and the like. Can be made.

  As mentioned above, Nd-Cu alloys and Nd-Al alloys are used as metal elements that have a remarkably lower melting point than Dy alloys and can improve coercive force performance and are relatively inexpensive. Can be mentioned.

  When the modified alloy is an Nd—Cu alloy, the melting point is as low as about 520 ° C., so the alloy is melted in the range of 520 to 650 ° C. Within this temperature range, the molten Nd—Cu can be diffused and permeated without coarsening the main phase constituting the composition of the quenched ribbon. Note that the “520 ° C.” includes a temperature range of about ± 5% in consideration of errors due to manufacturing conditions (room temperature, state of the manufacturing apparatus and its temperature, etc.).

  On the other hand, when the reforming alloy is an Nd-Al alloy, the melting point is 600 to 650 ° C., which is also a low temperature. Therefore, the molten Nd—Al is melted without coarsening the main phase constituting the quenching ribbon composition. Can diffuse and penetrate. The “600 to 650 ° C.” includes a temperature range of about ± 5% in consideration of errors due to manufacturing conditions (room temperature, manufacturing apparatus state, temperature, etc.).

  The rare earth magnets produced from the quenched ribbon produced by the above production method include, in addition to nanocrystalline magnets, sintered magnets and bonded magnets having a main phase (particle) size of 1 μm or more. In addition, since the manufactured rare earth magnets have enhanced coercive force performance, they are not only applied to drive motors for vehicles (particularly hybrid vehicles and electric vehicles), but also for various other purposes. For example, it can also be applied to products such as MEMS (Micro Electro Mechanical Systems).

  As can be understood from the above description, according to the method for producing a quenched ribbon for a rare earth magnet of the present invention, at least a predetermined surface roughness is imparted to the surface of the quenched ribbon precursor for the rare earth magnet, The rapid cooling ribbon of the modified alloy is brought into contact with the two, and both are pressurized to allow the rapid cooling ribbon of the modified alloy to enter the surface irregularities of the rapid ribbon precursor for the rare earth magnet. By melting the quenching ribbon and diffusing and infiltrating the inside of the quenching ribbon precursor for the rare earth magnet, the melt is diffused and penetrated throughout the entire area without wasting the quenching ribbon of the modified alloy used. Thus, a rapidly cooled ribbon for a rare-earth magnet with improved coercive force performance can be manufactured.

It is the schematic diagram explaining the 1st step of Embodiment 1 of the manufacturing method of the quenching ribbon for rare earth magnets of this invention. It is an arrow view of the II section of FIG. It is the schematic diagram explaining the 2nd step of Embodiment 1 of the manufacturing method in order of (a) and (b). It is the schematic diagram explaining the 2nd step of Embodiment 2 of the manufacturing method in order of (a) and (b). It is a figure which shows the experimental result which compared the coercive force performance of the quenching ribbon for rare earth magnets. It is the imaging figure which observed the adhesiveness of the quenching ribbon precursor according to the difference in surface roughness of the quenching ribbon precursor for rare earth magnets, and the quenching ribbon of the modified alloy, and (a) is the case of Ra = 0.04 It is an imaging diagram, (b) is an imaging diagram when Ra = 0.1, (c) is an imaging diagram when Ra = 0.5, and (d) is an imaging diagram when Ra = 2. It is a SEM image figure of the quenching ribbon for rare earth magnets in the case of Ra = 10.

  Hereinafter, an embodiment of a method for producing a quenching ribbon for a rare earth magnet according to the present invention will be described with reference to the drawings.

(Embodiment 1 of manufacturing method of quenching ribbon for rare earth magnet)
FIG. 1 is a schematic diagram for explaining the first step of the first embodiment of the method for producing a quenching ribbon for a rare earth magnet according to the present invention. FIG. 2 is a view taken along the arrow II in FIG. , B are schematic views illustrating the second step of the first embodiment of the manufacturing method in this order.

  As shown in FIG. 1, for example, an alloy ingot is melted at a high frequency by a melt spinning method using a single roll in a furnace (not shown) in an Ar gas atmosphere whose pressure is reduced to 50 kPa or less. A rapid cooling ribbon precursor B for a rare earth magnet is manufactured by spraying on a roll Ro.

  Here, the composition of the quenched ribbon precursor B is as follows: the main phase of RE-Fe-B system (at least one of RE: Nd and Pr) and the RE-X alloy (X: metal element) around the main phase. For example, in the case of a nanocrystalline structure, it consists of a main phase having a crystal grain size of about 50 nm to 200 nm.

  Here, the Nd—X alloy constituting the grain boundary phase is composed of Nd and at least one of Co, Fe, Ga, Cu, Al, etc., for example, Nd—Co, Nd—Fe, One of Nd—Ga, Nd—Co—Fe, and Nd—Co—Fe—Ga, or a mixture of two or more of these, is in an Nd rich state.

  The roll surface Ro1 of the rotating roll Ro is provided with unevenness Ro2 that forms a predetermined surface roughness as shown in FIG. 2, and a quenched ribbon precursor formed when a molten alloy ingot is injected onto the rotating roll Ro. As shown in FIG. 3 a, the unevenness Ro <b> 2 (predetermined surface roughness) of the roll surface Ro <b> 1 is transferred to the side surface of the body B on the roll surface Ro <b> 1 side, and a quenched ribbon precursor B for a rare earth magnet is manufactured. (First step).

  Here, it is desirable that the surface roughness is adjusted to a range of Ra = 0.05 μm to 5 μm. The surface roughness Ra is preferably as small as possible because the surface of the quenched ribbon is uniformly cooled. On the other hand, when Ra is 0.04 μm or less, the surface of the quenched ribbon precursor for rare earth magnets and the modified alloy Since the present inventors have specified that the quenched ribbons do not adhere to each other and the quenched ribbons are separated from each other, Ra is preferably 0.05 μm or more. On the other hand, if Ra exceeds 5 μm, the adhesiveness between the melted raw material and the roll surface of the rotating roll deteriorates during the rapid cooling when the rapid cooling ribbon is produced, and this decreases the rapid cooling rate, resulting in the generation of coarse particles. It has also been specified by the present inventors, and therefore, Ra is preferably 5 μm or less.

  Next, as shown in FIG. 3a, the surface of the quenched ribbon precursor B for rare earth magnets with the concavo-convex Bb facing upward is formed on the RE-Y alloy (Y: metal element) as a modified alloy. And does not contain heavy rare earth elements). The quenched ribbon D of the modified coating can also be produced by the same method and conditions as the quenched ribbon precursor for rare earth magnets, except for setting the melting temperature.

  Here, in the manufacturing method shown in the figure, as the RE-Y alloy, any one of Nd—Cu alloy and Nd—Al alloy is used. That is, in this manufacturing method, since the RE-Y alloy that is a modified alloy of the grain boundary phase of the quenched ribbon D is one that does not contain heavy rare earth elements such as Dy and Tb, it is compared with the Dy alloy. The melting point can be significantly reduced.

  When the modified alloy is an Nd-Cu alloy, its melting point is about 520 ° C (melt in the range of 520 to 650 ° C), and when it is an Nd-Al alloy, its melting point is about 600 to 650 ° C. However, both of them are remarkably low in temperature as compared with alloys such as Dy, and the problem of coarsening of crystal grains, which becomes a problem when using alloys such as Dy, cannot occur.

  As shown in FIG. 3a, by pressing the abutting quenching ribbon precursor B and the quenching ribbon D of the modified alloy (press P), a relatively soft quenching ribbon D is a relatively hard quenching ribbon precursor. As shown in FIG. 3b, the rapid cooling ribbon precursor B and the rapid cooling ribbon D of the modified alloy can be satisfactorily adhered to each other.

  When the interfaces of both the quenching ribbon precursor B and the quenching ribbon D of the reformed alloy are brought into close contact with each other, this is accommodated in a high temperature furnace (not shown), and the quenching ribbon D of the reforming alloy is placed in a high temperature atmosphere above the melting point of the reforming alloy As shown in FIG. 3b, the quenched ribbon D is melted and diffused and penetrated into the quenched ribbon precursor B (in the X direction) to produce a quenched ribbon for a rare earth magnet.

  According to the first embodiment of the manufacturing method shown in the figure, the rapid cooling ribbon of the modified alloy can be diffused and penetrated at a relatively low temperature, so that the main phase forming the rapid cooling ribbon for the rare earth magnet can be suppressed, Furthermore, it is possible to effectively diffuse and infiltrate the quenching ribbon precursor B without wasting all of the quenching ribbon D of the modified alloy used, so that there is no overall variation and high coercive force performance. A quenched ribbon for a rare earth magnet can be produced.

(Embodiment 2 of manufacturing method of quenching ribbon for rare earth magnet)
4a and 4b are schematic diagrams illustrating the second step of the second embodiment of the manufacturing method in this order.

  In Embodiment 2 of the manufacturing method, in the first step, a predetermined surface roughness (irregularity) is formed on the surface by the same method (only the melting temperature is changed) as that for manufacturing the quenched ribbon precursor for the rare earth magnet. A quenched ribbon D1 of a modified alloy having That is, the unevenness D1b is formed not only on the quenching ribbon precursor B for the rare earth magnet but also on the surface D1a of the quenching ribbon D1 of the modified alloy.

  Then, as shown in FIG. 4a, pressurization is performed in such a manner that the unevenness Bb of the rapid cooling ribbon precursor B for the rare earth magnet and the unevenness D1b of the surface D1a of the rapid cooling ribbon D1 of the modified alloy are engaged with each other.

  According to this method, since the pressurization is performed in a state where both the concaves and convexes Bb and D1b are engaged with each other, the relative shift can be completely eliminated, and the adhesion between the interfaces is further enhanced.

  When both interfaces are brought into close contact with each other, this is accommodated in a high temperature furnace (not shown), and the rapidly cooled ribbon D1 of the reformed alloy is melted as a high temperature atmosphere higher than the melting point of the reformed alloy, and melted as shown in FIG. 4b. D1 is diffused and penetrated into the quenched ribbon precursor B (X direction) to produce a quenched ribbon for a rare earth magnet.

  In addition, the manufactured rapid cooling ribbon for rare earth magnets is filled, for example, in a mold (not shown) (comprised of a die and a punch) and pressure-molded to manufacture a sintered body. When this is a nanocrystalline magnet, magnetic anisotropy is imparted to the sintered body by hot plastic working (strong working) to produce a rare earth magnet having a nanocrystalline structure.

  In addition to the rare-earth magnet of the nanocrystalline magnet, it is needless to say that the manufactured rapidly cooled ribbon for rare-earth magnet can be used for sintered magnets and bonded magnets having a particle size of 1 μm or more.

[Experiments comparing the coercivity performance of quenched ribbons for rare earth magnets and their results]
Based on the conditions for producing the quenched ribbon precursor for rare earth magnets shown in Table 1 below and the conditions for producing the quenched ribbon of the modified alloy shown in Table 2, the present inventors performed one-side cooling, A quenched ribbon having a composition of Nd29.9Pr0.4Fe64.2Co4.0B0.9Ga0.6 (mass%) and a quenched ribbon having a composition of Nd70Cu30 (at%) were prepared. Then, the side surfaces on both roll surfaces were bonded together, and pressure was applied (100 MPa) with a band press.

  Heat treatment was performed at 600 ° C. for 30 minutes in a high-temperature furnace, and the magnetic properties of the quenched ribbon (Example 1) for the rare earth magnet thus produced were evaluated.

  As Comparative Example 1, a rapid cooling ribbon for a rare earth magnet was manufactured with the surface roughness in Tables 1 and 2 set to Ra = 0.04 μm and the other conditions were the same.

  The result of magnetic characteristics is shown in FIG. From the figure, the coercive force was 18.7 kOe before diffusion of the modified alloy, whereas Example 1 was 23.6 kOe, and Comparative Example 1 was 19.6 kOe. It has been proven that there is.

  In this experiment, in the comparative example, the coagulation performance is sufficiently increased because the diffusion and penetration quenching ribbon is displaced during the heat treatment for diffusion and penetration of the modified alloy, and the diffusion and penetration is uneven. It is thought that it is not.

  On the other hand, the diffusion penetration area of the modified alloy is increased in Example 1, and the whole is effectively diffusing and penetrating. It is considered that the diffusion and permeation are uniform because the properties are good, and the coercive force performance is markedly higher than that of Comparative Example 1.

  Furthermore, the inventors of the present invention have a rapid cooling in both cases where the surface roughness Ra of the roll surface is 0.04 (Comparative Example 1) and 0.1 (Example 1), as well as 0.5 (Example 2) and 2 (Example 3). The interface between the ribbons was observed with an optical microscope to verify the interface adhesion. Each imaging figure is shown to FIG. Furthermore, a rapidly cooled ribbon for a rare earth magnet with Ra = 10 (Comparative Example 2) was manufactured, and an SEM image of the inside was taken. This is shown in FIG.

  6a to 6d, it can be seen that Examples 1, 2, and 3 have very good adhesion at the interface, while a large gap is generated at the interface of Comparative Example 1.

  On the other hand, from FIG. 7, in Comparative Example 2, it can be confirmed that a coarse grain region is present therein. This is thought to be due to the poor adhesion between the melted raw material and the roll surface of the rotating roll during the rapid cooling when the rapid cooling ribbon is produced, which decreases the rapid cooling rate and consequently promotes the coarsening of the particles.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

  Ro ... rotating roll, Ro1 ... roll surface, Ro2 ... irregularities (predetermined surface roughness), B ... quenching ribbon precursor for rare earth magnets, Ba ... one side, Bb ... irregularities (predetermined surface roughness), D, D1 ... quenched ribbon of modified alloy, D1b ... irregularities (predetermined surface roughness)

Claims (6)

Composition composed of a RE-Fe-B main phase (at least one of RE: Nd and Pr) and a RE-X alloy (X: a metal element and no heavy rare earth element) around the main phase A rapidly cooled ribbon precursor for a rare earth magnet in which the surface roughness of the roll surface is transferred to one side surface of the alloy ingot by melting the alloy ingot and injecting the alloy ingot onto a rotating roll having a roll surface with a predetermined surface roughness A first step of manufacturing
The surface of the quenched ribbon precursor for the rare earth magnet having the surface roughness is brought into contact with a modified ribbon RE-Y alloy (Y: a metal element and not containing a heavy rare earth element). First, the RE-Y alloy melt is diffused and infiltrated into the quenching ribbon precursor for the rare earth magnet to produce a quenching ribbon for the rare earth magnet. A method for producing a quenching ribbon for a rare earth magnet comprising two steps. In the first step, in addition to manufacturing a quenched ribbon precursor for a rare earth magnet, the alloy ingot of the modified alloy is melted and sprayed onto a rotating roll having a roll surface with a predetermined surface roughness. By doing so, to produce a rapid cooling ribbon of a modified alloy in which the surface roughness of the roll surface is transferred to one side thereof,
2. The rare earth magnet quench ribbon according to claim 1, wherein in the second step, the surfaces of the quenching ribbon precursor for the rare earth magnet and the quenching ribbon of the reformed alloy are pressed against each other having the surface roughness. Manufacturing method.   The method for producing a quenched ribbon for a rare earth magnet according to claim 1 or 2, wherein the surface roughness is in the range of Ra = 0.05 µm to 5 µm.   The RE-Y alloy is an Nd-Cu alloy, and in the second step, the Nd-Cu alloy is melted at a temperature of 520 to 650 ° C to diffuse and penetrate the Nd-Cu alloy melt. The manufacturing method of the quenching ribbon for rare earth magnets in any one of these.   The RE-Y alloy is an Nd-Al alloy, and in the second step, the Nd-Al alloy is melted at a temperature of 600 to 650 ° C to diffuse and permeate the Nd-Al alloy melt. The manufacturing method of the quenching ribbon for rare earth magnets in any one of these.   The method for producing a rapid cooling ribbon for a rare earth magnet according to any one of claims 1 to 5, wherein the rare earth magnet is a nanocrystalline magnet.

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