JP2003211257A - Manufacturing method of quenching roll for manufacturing rare earth alloys - Google Patents

Abstract

(57) [Problem] To provide a rare earth magnet having substantially the same performance as a rare earth magnet manufactured by using a quenching roll at the time of new production even if a process for regenerating damage caused by use is performed. Provided is a method for producing a quenching roll for producing a rare earth alloy which can be produced stably over a period. SOLUTION: A predetermined amount is removed from the outer peripheral surface of a quenching roll for producing a rare earth alloy having a main body having a heat conductive layer formed on an outer peripheral portion thereof and a metal layer formed on the outer peripheral portion of the heat conductive layer,
After the center line average roughness of the outer peripheral surface of the rare earth alloy-producing quenching roll after removal is set to 1 to 50 μm, the thickness t defined by the following equation is applied to the outer peripheral surface of the rare earth alloy producing quenching roll. By forming the metal layer _1, a quenching roll for producing a rare earth alloy is produced. t ₁ = (L−t ₂ ) × (ρ ₁ / ρ ₀ ) / (1.1+ (n−1) × 0.1) × ln (R
a ^1/3 +2) × β

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for manufacturing a quenching roll for manufacturing a rare earth alloy.

[0002]

Demand for high-performance magnets is increasing.
Rare earth magnets such as Nd-Fe-B sintered magnets are alloys whose composition is adjusted to contain a predetermined element (hereinafter, alloys containing such rare earths are collectively referred to as "rare earth alloys"). It is produced by crushing the metal strip obtained by quenching the molten metal of 1) into powder, or quenching to obtain a powder directly, and sintering the obtained powder. In order to improve the performance of the rare earth magnet manufactured in this way,
It is extremely important that not only the composition of the alloy exists within a predetermined range, but also that the structure of the alloy is dense and uniform.

For example, Nd-Fe having a structure suitable for a magnet
-When manufacturing a B-based sintered magnet, a molten metal having a predetermined composition obtained by melting a raw material powder mainly composed of Nd, Fe, and B in a vacuum furnace is applied to the outer peripheral portion of the rotating quenching roll. A so-called roll quenching method is used in which the melt is instantly rapidly cooled and solidified by bringing it into contact with each other by flowing it down to produce a desired ribbon made of a rare earth alloy.

A quenching roll used when carrying out this roll quenching method is usually a copper alloy or the like having good heat conduction in the outer peripheral portion of a steel body (core portion) in order to increase the amount of heat removed from the molten metal. Is formed of a heat conductive layer.

When a ribbon of a rare earth alloy is manufactured by such a roll quenching method, the quenching roll is always in contact with the molten metal and the molten metal is rapidly solidified. It is easily damaged by cracks.

Therefore, in order to prevent such damage to the heat conducting layer on the outer peripheral portion of the quenching roll, Japanese Patent Application Laid-Open No. 9-1296 discloses that Ni or Ni is further formed on the outer peripheral portion of the heat conducting layer.
It is disclosed that a metal layer such as Cr is formed by plating, for example.

[0007]

The metal layer formed on the outer peripheral portion of the quenching roll disclosed in Japanese Patent Application Laid-Open No. 9-1296 also suffers from thermal cracks and cracks due to repeated production of ribbons of rare earth alloys. Damage such as local wear occurs. The damaged metal layer is easily peeled off, and if it is peeled off, it is necessary to remove the part or the entire surface and then repair the metal layer by forming a new metal layer again.

However, when the quenching roll is used while repeating the repair of the metal layer in this way, when the metal layer is peeled off, the heat conductive layer underneath is also scraped off, so that the metal layer is formed again on this. Even if it does, the roll diameter gradually decreases as compared with the quenching roll when newly manufactured. Therefore, the thickness of the heat conduction layer is reduced, and the cooling performance of the cooling roll for the molten metal is increased every time the metal layer is repaired.

As described above, when the cooling performance of the quenching roll is increased by the regeneration, the particles of the structure are refined and the characteristics of the powder obtained by the pulverization in the subsequent step are changed. Therefore, the pressing before sintering is performed well. Can't do it. On the other hand, on the contrary, when the cooling performance of the quenching roll is reduced by regeneration, such as when the metal layer is formed thick, the grain structure of the rare earth magnet produced becomes coarse and the Fe ₂ Nd ₁₇ phase and
Since the Fe layer is microscopically deposited, the magnet characteristics are extremely deteriorated. Therefore, in any case, the performance of the manufactured rare earth magnet greatly fluctuates.

Therefore, even if the quenching roll disclosed in Japanese Patent Application Laid-Open No. 9-1296 is used, the performance of the rare earth magnet produced is the same as that of the rare earth magnet produced using the quenching roll at the time of new production. It is more likely to deteriorate, and the quality of the rare earth magnet produced by this quenching roll cannot be stably maintained for a long period of time.

It is an object of the present invention to provide a method for manufacturing a quenching roll for producing a rare earth alloy, and more specifically, even if a treatment for regenerating damage caused by use is performed, To provide a method for producing a quenching roll for producing a rare earth alloy, which can stably produce a rare earth magnet having a performance substantially equivalent to that of a rare earth magnet produced by using a quenching roll at the time of new production. Is.

[0012]

Means for Solving the Problems In order to solve the above-mentioned problems, the inventors of the present invention have achieved a quenching roll for producing a rare earth alloy after repairing a cooling roll having almost the same cooling performance as a quenching roll for producing a rare earth alloy at the time of new production. It was necessary to continue to maintain the heat conduction layer, and for that purpose, it was necessary to make the heat conductivity of the heat conduction layer or the portion of the heat conduction layer and the metal layer combined as constant as possible before and after the reproduction.

Generally, in order not to change the cooling performance of the quenching roll, the metal layer or the heat conducting layer is returned to the state before the damage so that it has the same thickness as the peeled metal layer or the heat conducting layer. It should be formed, but this is not realistic because repair costs are extremely high.

Further, even if the quenching roll thus regenerated is used, it is not possible to manufacture a rare earth magnet having a performance substantially equivalent to that of the rare earth magnet manufactured by using the newly manufactured quenching roll. found. This is because even if a certain amount of the damaged quenching roll metal layer is removed, the roughness of the surface increases, so even if a new metal layer is formed on it, the metal on the quenching roll at the time of new manufacturing It is considered that the cooling performance is different from that of forming the layer.

From these points of view, as a result of intensive investigations by the present inventors, the cooling rate of the molten metal by the quenching roll in which the metal layer is formed on the outer peripheral portion of the heat conducting layer by means such as plating is within a predetermined range. Based on the basic recognition that it is important to control in, the result of diligent study on the regeneration of the worn quenching roll, the outer peripheral surface of the metal layer of the quenching roll for rare-earth alloy production damaged by use, After removing so that the centerline average roughness is 1 to 50 μm, at least the thermal conductivity of the metal layer to be formed, the thermal conductivity of the removed outer peripheral metal layer, and the removed rare earth system By forming a metal layer having a thickness defined based on the center line average roughness Ra of the outer peripheral surface of the alloy production quenching roll,
The inventors have found that the above problems can be solved, and have conducted further studies to complete the present invention.

According to the present invention, a predetermined amount of the outer peripheral surface of a quenching roll for producing a rare earth alloy, which has a main body having a heat conducting layer formed on the outer peripheral portion and a metal layer formed on the outer peripheral portion of the heat conducting layer, is removed, After the center line average roughness of the outer peripheral surface of the quenching roll for producing the rare earth alloy after removal is set to 1 to 50 μm, at least the thermal conductivity of the metal layer to be formed on the outer circumferential surface of the quenching roll for producing the rare earth alloy. Rate, the thermal conductivity of the removed metal layer on the outer peripheral surface, and the centerline average roughness of the outer peripheral surface of the removed quenching roll for producing a rare earth alloy alloy. It is a method for producing a quenching roll for producing a rare earth alloy, which is characterized in that it is formed.

In the method for manufacturing a quenching roll for producing a rare earth alloy according to the present invention, the thickness of the metal layer to be formed is such that the thermal conductivity of the quenching roll for producing a rare earth alloy having the metal layer is this rare earth alloy. It is exemplified that the quenching roll for alloy production is regulated so as to have almost the same thermal conductivity as a new product.

From another point of view, the present invention provides a metal layer of a quenching roll for producing a rare earth alloy, comprising a main body having a heat conductive layer formed on the outer peripheral portion thereof and a metal layer formed on the outer peripheral portion of the heat conductive layer. After removing a predetermined amount, the center line average roughness of the outer peripheral surface of the quenching roll for producing the rare earth alloy after removal is set to 1 to 50 μm, and then the following (1 ) A method for producing a quenching roll for producing a rare earth alloy, characterized in that a metal layer having a thickness (t ₁ ) defined by the formula is formed.

T ₁ = (L−t ₂ ) × (ρ ₁ / ρ ₀ ) / (1.1+ (n−1) × 0.1) × ln (Ra ^1/3 +2) × β (1) However, in the equation (1), L represents the radius (mm) of the quenching roll for manufacturing the rare earth alloy alloy when newly manufactured, t ₁ represents the thickness (mm) of the metal layer to be formed, and t ₂ represents The radius (mm) of the quenching roll for rare earth alloy production that has been removed is shown, ρ ₁ is the thermal conductivity [W / (m ・ ° C)] of the metal layer to be formed, and ρ ₀ is the removal rate. Shows the thermal conductivity [W / (m · ° C)] of the metal layer on the outer peripheral surface, and Ra represents the center line average roughness (μm) of the surface of the quenched roll for production of the rare earth alloy after removal, n indicates the number of times of removal (the first removal is 1, and thereafter 2, 3, ...), β is an arbitrary value that satisfies 0.9 or more and 1.1 or less,
Furthermore, ln indicates the natural logarithm.

In the method for producing a quenching roll for producing a rare earth alloy according to the present invention, when the metal layer to be removed is composed of a stack of two or more metal layers, and / or by removal, heat conduction is carried out together with the metal layer. When the layer is removed, it is exemplified to further define the thickness (t ₁ ) based on the following formula (2).

However, the removed metal layers (including the removed heat-conducting layer) are sequentially arranged as the first layer, ..., The m-th layer ,.
Where Σ represents the sum over all removed metal layers.

(L −t ₂ ) / ρ ₀ = Σt _m / ρ _m (2) However, t _m exists in the quenching roll for manufacturing rare earth alloy at the time of new production and is removed. The thickness (mm) of the m-th layer, which does not exist in the subsequent quenching roll for producing a rare earth alloy, is shown, and ρ _m is the thermal conductivity [W / (m · ° C)] of the m-th layer.

In the method for producing a quenching roll for producing a rare earth alloy according to the present invention, when the metal layer to be formed is a laminate of two or more metal layers, the following formula (3) is used. It is exemplified that the thickness (t _{m ′} ) of each metal layer to be formed is defined by the thickness (t ₁ ).

However, the metal layers to be formed are the first layer, ...
.., m-th layer, ..., And Σ in the following equation represents the sum of all the metal layers formed. _{t 1 / ρ 1 = Σt m} '/ ρ m' ······· (3) However, t _{m 'is} the m' indicates the thickness of the layer (mm), ρ _{m 'is} the m' layer The thermal conductivity [W / (m ・ ℃)] of is shown.

In all of the methods for manufacturing a quenching roll for producing a rare earth alloy according to the present invention, the metal layer on the outer periphery of the quenching roll for producing a rare earth alloy is a metal plating layer, and the removal is a metal layer or What is done with the metal layer and the heat conducting layer is illustrated.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) An embodiment of a method for manufacturing a quenching roll for producing a rare earth alloy according to the present invention will be described in detail below. In the description of the first embodiment, the “metal layer on the outer circumference of the quenching roll for producing a rare earth alloy” in the present invention is a metal plating layer, and the “removal” in the present invention is a damaged metal layer. Take the example when it is done. However, the present invention is not limited to this mode, and is similarly applied to a metal layer formed by means other than plating.

As described above, even if a treatment for regenerating damage caused by use is performed, a rare earth magnet having a performance substantially equivalent to that of a rare earth magnet manufactured by using a quenching roll at the time of new production is used for a long time. In order to manufacture a quenching roll for rare earth alloy production that can be stably manufactured over a period of time, a cooling roll for rare earth alloy production after repairing has almost the same cooling performance as the quenching roll for rare earth alloy production at the time of new production. Therefore, it is necessary to make the thermal conductivity of the heat conductive layer as constant as possible before and after the reproduction.

However, if the metal plating layer or the heat conduction layer is formed in the state before the damage so that it has the same thickness as the peeled metal plating layer or the heat conduction layer, the repair cost will be significantly increased. Even if a quenching roll regenerated by grinding and removing the peeled metal plating layer is used, the roughness of the surface increases due to this grinding removal, so it is assumed that a new metal plating layer is formed on it. The cooling performance is different from the one with a metal plating layer formed on the quenching roll at the time of new manufacturing, so a rare earth magnet with performance almost equivalent to the rare earth magnet manufactured using the quenching roll at the time of new manufacturing is used. It cannot be manufactured.

Therefore, in the present embodiment, after removing the outer peripheral surface of the metal plating layer of the quenching roll for producing a rare earth alloy which has been damaged during use so as to have a center line average roughness of 1 to 50 μm, At least, the thermal conductivity of the metal plating layer to be formed, the thermal conductivity of the metal plating layer out of the removed outer peripheral surface, and the center line of the outer peripheral surface of the removed quenching roll for producing a rare earth alloy By forming a metal plating layer having a thickness specified based on the average roughness Ra, the cooling rate of the molten metal by a quenching roll having a metal plating layer formed by means such as plating on the outer peripheral portion of the heat conduction layer is provided. Control within a predetermined range.

Specifically, in the present embodiment, a quenching roll for producing a rare earth alloy is manufactured by performing two steps of (i) removal of the damaged metal plating layer and (ii) formation of the metal plating layer. That is, regeneration of a damaged quenching roll for producing a rare earth alloy is performed. Hereinafter, these two steps will be described in detail.

(I) Removal of Damaged Metal Plating Layer First, for the production of a rare earth alloy having a body having a heat conducting layer formed on the outer periphery and a damaged metal plating layer formed on the outer periphery of the heat conducting layer. A predetermined amount of the outer peripheral surface of the quenching roll is removed to remove a part of the damaged metal plating layer. The means for removal and the like may be a conventional method and is not limited to a specific means. For example, it is exemplified that the quenching roll for producing the rare earth alloy is set in a roll polishing device, and while the roll is rotated, a part of the surface thereof is ground and removed in the roll circumferential direction and the roll cylinder length direction.

By this removal of the damaged metal plating layer, a part in the thickness direction of the metal plating layer is removed. In the present embodiment, however, the removed outer peripheral surface of the quenching roll for producing a rare earth alloy is removed. The centerline average roughness Ra is limited to 1 μm or more and 50 μm or less. If the center line average roughness Ra of the outer peripheral surface after removal is 1 μm or more and 50 μm or less,
By forming a metal plating layer having a thickness obtained based on the equation (1), the cooling rate of the molten metal by the quenching roll having the metal plating layer formed on the outer peripheral portion of the heat conduction layer by means such as plating is set to a predetermined value. This is because the range can be controlled.

The center line average roughness of the outer peripheral surface after removal
Well-known means may be used for increasing Ra to 1 μm or more and 50 μm or less. In this way, in the present embodiment, the damaged metal plating layer is removed, whereby the center line average roughness Ra of the outer peripheral surface of the quenching roll for producing a rare earth alloy is 1 or less.
It is limited to not less than μm and not more than 50 μm.

(Ii) Formation of Metal Plating Layer In this embodiment, at least the outer peripheral surface of the quenching roll for producing a rare earth alloy thus removed, that is, the outer peripheral surface of the removed metal plating layer, is formed. The thermal conductivity of the metal plating layer to be performed, the thermal conductivity of the metal plating layer of the outer peripheral surface that has been removed, and the center line average roughness of the outer peripheral surface of the quenching roll for manufacturing the rare earth alloy alloy that has been removed. A metal plating layer having a thickness defined based on is formed.

At this time, the thickness of the metal plating layer to be formed is
The thermal conductivity of the quenching roll for producing a rare earth alloy, on which the metal plating layer is formed, is specified to be substantially equal to the thermal conductivity of the quenching roll for producing a rare earth alloy when it is new.

Here, the "thermal conductivity of the quenching roll for producing rare earth alloys" means the degree of heat conduction of the entire quenching roll for producing rare earth alloys, and specifically, for example, the thickness of each part of the roll. And the thermal conductivity of that portion.
Therefore, the thermal conductivity of each of the quenching roll for producing a rare-earth alloy and the quenching roll for producing a rare-earth alloy at the time of brand-new that the metal plating layer is formed is approximately equal to the thermal conductivity determined by the above-mentioned method of ± 20. It is meant to be included in the range of%.

That is, when the metal plating layer is formed on the outer peripheral surface of the removed quenching roll for producing a rare earth alloy, that is, the outer peripheral surface of the removed metal plating layer, the rare earth alloy for producing a rare metal alloy is formed. In order to make the thermal conductivity of the quenching roll approximately equal to the thermal conductivity of the new quenching roll for producing this rare earth alloy, the thickness of the metal plating layer to be formed has a large effect. To determine the thickness of, the thermal conductivity of the metal plating layer to be formed, the thermal conductivity of the metal plating layer of the removed outer peripheral surface, and the removed quenching roll for the rare-earth alloy production The center line average roughness of the outer peripheral surface has an influence. Therefore, in the present embodiment, the thickness of the metal plating layer is determined based on at least these three factors.

As the plating metal, for example, Ni, Cr or the like can be applied. In the plating method, a metal plating layer of Ni, Cr or the like is formed on the surface of a quenching roll for producing a rare earth alloy of this kind. Any means can be used and it is not limited to a specific means.

Specifically, in the present embodiment, not only the center line average roughness Ra of the surface of the quenching roll for producing a rare earth alloy which has been damaged by use, but also the number of regenerations n are taken into consideration,
The thickness t ₁ of the suitable metal layer defined by the following equation, to form a metal layer having a thickness of t ₁ to the outer peripheral surface of the grinding removed rare earth chill roll alloy preparation a part of the metal layer of the outer peripheral surface.

T ₁ = (L−t ₂ ) × (ρ ₁ / ρ ₀ ) / (1.1+ (n−1) × 0.1) × ln (Ra ^1/3 +2) × β (1) However, in the equation (1), L represents the radius (mm) of the quenching roll for manufacturing the rare earth alloy alloy when newly manufactured, t ₁ represents the thickness (mm) of the metal layer to be formed, and t ₂ represents The radius (mm) of the quenching roll for rare earth alloy production that has been removed is shown, ρ ₁ is the thermal conductivity [W / (m ・ ° C)] of the metal layer to be formed, and ρ ₀ is the removal rate. Shows the thermal conductivity [W / (m · ° C)] of the metal layer on the outer peripheral surface, and Ra represents the center line average roughness (μm) of the surface of the quenched roll for production of the rare earth alloy after removal, n indicates the number of times of removal (the first removal is 1, and thereafter 2, 3, ...), β is an arbitrary value that satisfies 0.9 or more and 1.1 or less,
Further, ln represents the natural logarithm.

The thickness t ₁ calculated by the equation (1) is most preferably the center value, that is, β = 1, but ± 10% when the performance of the rare earth alloy magnet produced is taken into consideration.
Within the range of, that is, in the range where β is 0.9 or more and 1.1 or less, it is allowed.

From the equation (1), it can be seen that the thickness t ₁ also increases as the center line average roughness Ra of the surface of the quenched roll for producing a rare earth alloy which has been removed increases. this is,
When the center line average roughness Ra is large, the heat conduction between the outer peripheral surface of the quenching roll for producing a rare earth alloy and the metal plating layer on the outside thereof becomes good, so that the metal plating layer of the metal plating layer should be compensated for this. This is probably because it is necessary to increase the thickness.

When the number of times of regeneration is increased, microscopic gaps are formed on the surface of the quenching roll for producing a rare earth alloy and the thermal conductivity between the quenching roll for producing a rare earth alloy and the metal plating layer is deteriorated. , It is necessary to reduce the thickness of the metal plating layer.

In this way, a quenching roll for producing a rare earth alloy is produced. According to the quenching roll for manufacturing the rare earth alloy of the present embodiment manufactured in this way, the thermal conductivity of the metal plating layer to be formed and the heat conductivity of the metal plating layer of the removed outer peripheral surface. The thickness t ₁ of the metal plating layer to be formed is determined by taking into consideration not only the rate but also the center line average roughness of the outer peripheral surface of the quenched roll for producing a rare earth alloy that has been removed, and the number of times of removal. Therefore, it is possible to control the thermal conductivity of the metal plating layer so that the quenching roll used in the quenching method has the same cooling performance as that of the quenching roll at the time of new production even if the damage progresses. , Stable production of rare earth magnets that have approximately the same performance as the rare earth magnets produced using the rapidly cooling rolls at the time of new production, even after treatment for damage recovery due to use Rapid production of rare earth alloys It is possible to provide a roll.

(Second Embodiment) Next, a second embodiment of the present invention will be described. In the description of the second embodiment, the "metal layer on the outer periphery of the quenching roll for producing a rare earth alloy" in the present invention is the metal plating layer, which is the same as the above-described first embodiment, The “removal” in the present invention is different from that of the first embodiment in that the metal plating layer to be removed is formed by stacking two or more metal plating layers, or is performed on both the metal layer and the heat conduction layer. There are differences.

When the metal plating layer to be removed is formed by stacking two or more metal layers, or when the metal plating layer as well as the heat conductive layer is removed by the removal,
It is exemplified that the thickness t ₁ is defined based on the following equation (2) together with the equation (1).

However, the removed metal layers (including the removed heat-conducting layer) are sequentially arranged as the first layer, ..., The m-th layer ,.
Where Σ represents the sum over all removed metal layers.

(L−t ₂ ) / ρ ₀ = Σt _m / ρ _m (2) However, in the formula (2), t _m is a quenching roll for manufacturing a rare earth alloy when newly manufactured. Is present and indicates the thickness (mm) of the m-th layer that does not exist in the quenching roll for producing the rare earth alloy after removal, and ρ _m is the thermal conductivity [W / (m · ° C)] of the m-th layer. Show.

When the metal layer to be formed is formed by laminating two or more metal layers, the above formulas (1) and (2) are further added.
It is exemplified that the thickness (tm ′) of each metal layer to be formed is defined from the thickness (t ₁ ) based on the equation (3) together with the equation.

However, the metal layers to be formed are the first layer, ...
.., m-th layer, ..., And Σ in the following equation represents the sum of all the metal layers formed. _{t 1 / ρ 1 = Σt m} '/ ρ m' ····· (3) However, in (3), t m _'is the m' indicates the thickness of the layer (mm), [rho _{m 'is} The thermal conductivity [W / (m · ° C)] of the m'th layer is shown.

Thus, the metal plating layer to be removed is 2
Even if it is composed of more than two metal layers, by using the above equations (2) and (3), the thickness of the metal plating layer to be formed can be accurately calculated using the equation (1). You can ask.

[0052]

EXAMPLES The present invention will be described more specifically with reference to examples. A rare earth magnet alloy was produced using the roll quenching method under the conditions described below.

(Nd + Pr): 31% by mass, B: 1% by mass, and 100 kg of the raw material metal with the balance Fe at 1500 ° C. in a vacuum furnace.
Then, the melt obtained above was poured onto the upper surface of a quenching roll for producing a rare earth alloy for 60 revolutions / minute to produce a ribbon of a rare earth magnet alloy. The time required for one production was about 30 minutes. The rare earth alloy production quenching roll is a rare earth alloy production quenching body having a main body having a 30 mm thick copper heat conduction layer formed on the outer periphery and a metal plating layer formed on the outer periphery of the heat conduction layer. It is a roll and has an outer diameter of 15
The width is 0 mm, the width of the part in contact with the molten metal is 100 mm, and the inside is cooled by running water.

The characteristics of the produced alloy were measured by an optical microscope (200
(2 times) and the CPU were used to evaluate the average minor axis diameter of the main phase by image analysis and the press characteristics (whether press molding is possible) in the alloy powder press performed for sintering.

When the alloy production was repeated 200 times in this manner, the surface of the quenching roll for producing the rare earth alloy produced large irregularities. There is a possibility that there will be a problem that the release from the roll becomes unstable.

Therefore, this quenching roll for producing a rare earth alloy was regenerated under the following conditions. (1) Copper on the roll surface was ground and removed by 1 mm. The center line average roughness Ra of the roll surface after grinding and removal was 1 μm. Aluminum plating 768 μ on this surface by electroplating
m applied. Under this condition, the thickness t ₁ calculated from equation (1) above is 766 μm because the thermal conductivity of copper is 227 W / m ° C and the thermal conductivity of aluminum is 174 W / m ° C. It was That is, the formed aluminum plating thickness is
It was about 100.26% of the thickness calculated from equation (1).

A rare earth alloy was produced under the above conditions using the quenching roll for producing the rare earth alloy thus regenerated, and the main phase average minor axis diameter and press characteristics of the produced alloy were measured. As a result, the average minor axis diameter of the main phase was 3 to 6 μ.
m was also good, and the press characteristics were also good.

(2) On the other hand, 400 μm aluminum plating
However, the short axis diameter of the main phase was as small as 1 to 3 μm, and the press characteristics were poor.

(3) The copper on the surface of the quenching roll for producing a rare earth alloy was ground and removed by 1 mm. Surface centerline average roughness Ra is 1
It was μm. This surface was nickel-plated to a thickness of 205 μm by electroplating. Under this condition, the thickness t ₁ calculated from equation (1) above was 207 μm because the thermal conductivity of copper is 227 W / m ° C and the thermal conductivity of nickel is 47 W / m ° C. . That is, the formed nickel plating thickness is (1)
It was about 99.03% of the thickness calculated from the formula.

A rare earth alloy was produced under the above conditions using the quenching roll for producing a rare earth alloy thus regenerated, and the main phase average minor axis diameter and press characteristics of the produced alloy were measured. As a result, the average minor axis diameter of the main phase was 3 to 6 μ.
m was also good, and the press characteristics were also good.

(4) On the other hand, nickel plating with a thickness of 260 μm (about 125.60 of the thickness calculated from equation (1))
%), The average minor axis diameter of the main phase becomes coarse at 8 to 200 μm,
It could not be used as a magnet.

(5) The surface of the quenching roll for producing a rare earth alloy was ground by 1 mm. The surface Ra was 1 μm. Copper plating was applied on this surface by electroplating to a thickness of 998 μm.
Under this condition, t ₁ calculated from the above equation (1) was 999 μm because the thermal conductivity of copper was 227 W / m ° C and the thermal conductivity of nickel was 47 W / m ° C. That is, the formed copper plating thickness was about 99.90% of the thickness calculated from the equation (1).

A rare earth alloy was produced under the above conditions using the quenching roll for producing the rare earth alloy thus regenerated, and the main phase average minor axis diameter and press characteristics of the produced alloy were measured. As a result, the average minor axis diameter of the main phase was 3 to 6 μ.
m was good, and the press characteristics were also good.

(6) On the other hand, copper plating with a thickness of 1200 μm (about 120.12% of the thickness calculated from equation (1)) is
The major axis minor axis diameter was as large as 8 to 200 μm and could not be used for magnets.

[0065]

As described in detail above, according to the method for manufacturing a quenching roll for manufacturing a rare earth alloy according to the present invention, even if a treatment for regenerating damage caused by use is performed, A rare earth magnet having substantially the same performance as a rare earth magnet manufactured using a quenching roll can be stably manufactured for a long period of time.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yukihiro Ebisawa             1850 Minato Minato, Wakayama, Wakayama Sumikin Morico             Group Co., Ltd. (72) Inventor Masaru Nakamura             1850 Minato Minato, Wakayama, Wakayama Sumikin Morico             Group Co., Ltd. F-term (reference) 4E004 DB02 DB03 DB16 QA01 QA03                       TA03

Claims (6)

[Claims] 1. A predetermined amount of an outer peripheral surface of a quenching roll for producing a rare earth alloy, which has a main body having a heat conducting layer formed on the outer peripheral portion and a metal layer formed on the outer peripheral portion of the heat conducting layer, is removed and then removed. After the center line average roughness of the outer peripheral surface of the quenching roll for producing the rare earth alloy is set to 1 to 50 μm, at least on the outer peripheral surface of the quenching roll for producing the rare earth alloy, the thermal conductivity of the metal layer to be formed and , The thermal conductivity of the metal layer on the outer peripheral surface after the removal, and a metal layer having a thickness defined based on the center line average roughness of the outer peripheral surface of the removed quenching roll for producing a rare earth alloy. A method for producing a quenching roll for producing a rare earth alloy, which comprises forming. 2. The thickness of the metal layer to be formed is such that the thermal conductivity of the quenching roll for producing a rare earth alloy having the metal layer is substantially the same as the thermal conductivity of the quenching roll for producing a rare earth alloy when it is new. The method for producing a quenching roll for producing a rare earth alloy according to claim 1, which is defined so as to be equal. 3. A predetermined amount of the metal layer of a quenching roll for producing a rare earth alloy, which has a main body having a heat conductive layer formed on the outer peripheral portion and a metal layer formed on the outer peripheral portion of the heat conductive layer, is removed and removed. After setting the center line average roughness of the outer peripheral surface of the quenching roll for producing the rare earth alloy below to 1 to 50 μm, the thickness (t _{1. A} method for producing a quenching roll for producing a rare earth alloy, which comprises forming the metal layer of ₁ ). t ₁ = (L−t ₂ ) × (ρ ₁ / ρ ₀ ) / (1.1+ (n−1) × 0.1) × ln (R
a ^1/3 ＋2) × β L: Radius (mm) t ₁ of newly manufactured quenching roll for rare earth alloy production t: Thickness of the metal layer to be formed (mm) t ₂ : Rare earth after the removal Radius (mm) of the quenching roll for producing a system alloy ρ ₁ : Thermal conductivity of the formed metal layer [W / (m · ° C)] ρ ₀ : Thermal conductivity of the metal layer on the outer peripheral surface after the removal
[W / (m · ° C.)] Ra: center line average roughness (μm) of the surface of the quenching roll for producing the rare earth alloy alloy that has been removed, n: number of times of removal (first removal is 1) , And thereafter 2, 3, ...) β: Any value that satisfies 0.9 or more and 1.1 or less ln: Natural logarithm 4. When the metal layer to be removed consists of a stack of two or more metal layers, and / or when the removal removes the heat conducting layer together with the metal layer, The method for producing a quenching roll for producing a rare earth alloy according to claim 3, wherein the thickness (t ₁ ) is defined based on a formula. However, the removed metal layers (including the removed heat conduction layer) are sequentially arranged in the order of the first layer, ..., The m-th layer ,.
, And Σ in the equation below represents the sum for all removed metal layers. _{(L -t 2) / ρ 0} = Σt m / ρ m t m: present in new products when rare-earth alloy for producing quenching rolls, the not present in the rare earth-based alloy for producing chill roll after the removal Thickness of m layer (mm) ρ _m : Thermal conductivity of m layer [W / (m ・ ℃)] 5. When the metal layer to be formed is a laminate of two or more metal layers, the thickness is further calculated based on the following formula.
The method for producing a quenching roll for producing a rare earth alloy according to claim 3 or 4, wherein the thickness (t _{m '} ) of each metal layer formed from (t ₁ ) is defined. However, the metal layers to be formed are sequentially the first layer, ..., The m'th layer, ..., And Σ in the following equation represents the sum of all the metal layers to be formed. _{t 1 / ρ 1 = Σt m} '/ ρ m' t m: thickness of _'the m' layer (mm) ρ _m: thermal conductivity of _'the m' layer [W / (m · ℃) ] 6. The metal layer on the outer circumference of the quenching roll for producing a rare earth alloy is a metal plating layer, and the removal is performed on the metal layer or on the metal layer and the heat conducting layer. 6. A method for manufacturing a quenching roll for manufacturing a rare earth alloy according to any one of claims 1 to 5.