JP2002265933A - Magnetic abrasive tool produced by electroless plating method and magnetic abrasion method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool to use for a magnetic abrasion method which enables polishing of a complicate shape or an inner tubular surface. SOLUTION: The magnetic abrasive tool comprises an abrasive grain layer coating only the surface of a metal powder to support an ultra abrasive grain such as diamond and CBN or a usual abrasive grain such as W, GC and an emery on the surface, preferably the abrasive grain layer supporting the abrasive grain firmly with a uniform injection level and a homogeneous distribution, wherein the abrasive grain layer is prepared by using an electroless plating method, more concretely the method which pretreats not only a magnetic powder but also the abrasive grain so that the abrasive grain may be supported in increased number per unit area of the tool surface though a constant weight of the grain is dipped in a plating solution; or the method which controls the weight of the abrasive grain, the thickness of a plating membrane and the particle size of the abrasive grain to use so that the abrasive grain may be regulated in density and injection height in the abrasive grain layer. The magnetic abrasive method uses the magnetic abrasive tool. The method enables polishing of an aluminum inner tubular surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic polishing tool manufactured by an electroless plating method.

[0002]

2. Description of the Related Art There is a magnetic polishing method as a method capable of processing parts which are difficult to machine. The magnetic polishing method originated in basic research by Baron of Leningrad University and research of "grinding in a magnetic field" by Madkensky of the same university. It is a polishing technology that was introduced in Japan and is currently being actively studied for practical use. This polishing method is, as described above, for parts with complicated shapes that were difficult to process conventionally, for holes and circular pipe inner surfaces where tools do not enter,
This is a polishing method that can perform precision finish polishing without losing the shape. Some examples have been put to practical use in polishing the inner surface of a flexible tube and deburring and polishing a hard disk head.

FIG. 9 is a schematic view showing (a) a planar magnetic polishing method and (b) a circular pipe inner magnetic polishing method. In the magnetic polishing method, magnetic abrasive grains composed of a magnetic material and abrasive grains are used as a polishing tool. The processing proceeds by generating a polishing pressure by the action of the magnetic force lines on the polishing tool and causing relative movement between the polishing tool and the workpiece. There are two methods of giving relative motion: a method of fixing the workpiece and giving rotation and feed to the magnetic pole, and a method of fixing the magnetic pole and giving feed to the workpiece (table, lathe spindle, etc.) according to the shape of the workpiece. Either method is selected. Important factors that affect the quality of the finished surface by the magnetic polishing method include the state of interference between the tool and the workpiece and the efficient transmission of the polishing pressure. Therefore, optimization of magnetic pole arrangement, development of high performance tools, etc. are indispensable.

Examples of the polishing tool used in the magnetic polishing method include simple mixed type magnetic abrasive grains, magnetic abrasive grains obtained by sintering and pulverizing abrasive grains and a magnetic substance, and magnetic abrasive grains obtained by a plasma powder melting method. Simple mixed type magnetic abrasive grains are obtained by simply mixing magnetic powder, abrasive grains, and oils (or grinding fluids), and require no labor for tool preparation and preparation. Simple mixed type magnetic abrasive grains are relatively frequently used because they are easy to handle. However, there are problems in that the abrasive particles are dispersed on the surface of the magnetic powder, the amount of abrasive particles projected is non-uniform, and the abrasive particle holding power is low. The abrasive grains are easily separated and fall off from the magnetic powder during processing, and the processing pressure is inefficient, so that the processing efficiency is deteriorated. Further, as shown in the interference state between the tool and the workpiece shown in FIG. 10, there is a high possibility that the magnetic particles directly contact the workpiece. The work surface may be contaminated. However, in this case, there is a problem that it is not suitable for reuse because it is difficult to separate chips and abrasive grains.

The magnetic abrasive grains obtained by sintering and pulverizing the abrasive grains and the magnetic substance are in a powder form, and since the abrasive grains and the magnetic substance are sintered by powder metallurgy, they have excellent abrasive grain holding power. However, on the surface of the pulverized tool, there is a high possibility that the dispersion state of the abrasive grains and the projection amount of the abrasive grains become uneven. In this case, as in the case described above, the transmission of the processing pressure and the state of interference between the magnetic body and the workpiece deteriorate. The magnetic abrasive grains obtained by the plasma powder melting method are powdery magnetic abrasive grains obtained by mixing a metal melted at a high temperature and the abrasive grains, followed by cooling and pulverization. FIG. 11 shows a schematic diagram of a method for manufacturing this tool. It is produced by pulverizing a metal-abrasive mixed mass obtained by this method, and has a high abrasive holding power. However, when abrasive grains (diamond or the like) having a lower specific gravity than the magnetic metal material are used, the abrasive grains float in the molten metal, and unevenness occurs in the dispersed state of the abrasive grains. In addition, there is a report that oxide-based abrasive grains have low affinity with iron-based magnetic substances, and that sufficient abrasive-grain holding power cannot be obtained. From these, there is a problem that there is a low possibility that a tool holding the abrasive grains uniformly and firmly is obtained, and there is a limit to the types of abrasive grains that can be used. In order to produce this tool, a special device as shown in FIG. 11 is required. Also, as a common problem described above, since both are made by crushing a mixed mass of magnetic material and abrasive grains, the abrasive grains on the obtained tool are present not only on the magnetic material surface but also inside the magnetic material. there's a possibility that. The abrasive grains present inside the magnetic material do not directly participate in the processing. Also, when using super-abrasive grains such as diamond and CBN, the presence of abrasive grains not involved in the processing is a factor that hinders the reduction of raw material costs.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a magnetic polishing method capable of polishing a complicated shape or the inner surface of a pipe (straight pipe or deformed pipe). An object of the present invention is to provide a tool provided with an abrasive layer having an abrasive protrusion amount and a sufficient abrasive holding force. Another object of the present invention is to provide a magnetic polishing method with improved polishing efficiency (reduced surface roughness, reduced processing time) and an expanded range of application.

[0007]

The gist of the present invention is a magnetic polishing tool in which an abrasive layer is provided only on the surface of a magnetic powder.

The abrasive layer is a layer of abrasive grains in which the abrasive grains are firmly held and uniformly distributed with a uniform protrusion amount. In this case, the present invention provides a method in which the abrasive grains are firmly held only on the surface of the magnetic powder with a uniform protrusion amount. The gist of the invention is a magnetic polishing tool having a uniformly distributed abrasive layer.

[0009] The abrasive grains are held on the surface of the magnetic powder using electroless plating. In this case, the present invention uses the electroless plating to hold the abrasive grains on the surface of the magnetic powder. The gist of the present invention is a magnetic polishing tool in which an abrasive layer, preferably an abrasive layer in which the abrasive grains are firmly held with a uniform protrusion amount and are uniformly distributed is arranged only on the surface of the magnetic powder.

[0010] Among the electroless plating conditions, even if the weight of the abrasive grains immersed in the plating solution is the same, the number of abrasive grains retained per unit area on the tool surface by pretreating not only the magnetic powder but also the abrasive grains In this case, the present invention, in the electroless plating conditions, even if the weight of the abrasive particles immersed in the plating solution is the same, by pre-processing not only the magnetic powder but also the abrasive particles on the tool surface Using electroless plating to increase the number of abrasive grains held per unit area, the abrasive grains were held on the surface of the magnetic powder, the abrasive layer only on the surface of the magnetic powder, preferably the abrasive grains were uniformly projected The gist of the present invention is a magnetic polishing tool provided with an abrasive grain layer which is firmly held in an amount and uniformly distributed.

In electroless plating, by adjusting the weight of the abrasive grains immersed in the plating solution, the thickness of the plating film, and the particle size of the abrasive grains used, the abrasive grain density and the abrasive grain protrusion height in the abrasive grain layer can be reduced. In this case, the present invention adjusts the weight of the abrasive grains immersed in the plating solution, the thickness of the plating film, and the particle diameter of the abrasive grains to be used, so that the abrasive grain density in the abrasive grain layer and the abrasive grains are adjusted. Using an electroless plating whose protrusion height has been adjusted, the abrasive grains are held on the surface of the magnetic powder.The abrasive layer is formed only on the surface of the magnetic powder, preferably the abrasive grains are firmly held with a uniform protrusion amount. The gist of the invention is a magnetic polishing tool having a uniformly distributed abrasive layer.

The magnetic powder is a metal powder, and the abrasive grains are superabrasive grains such as diamond and CBN or general abrasive grains such as WA, GC, and emery. In this case, the present invention uses electroless plating, More specifically, among the electroless plating conditions, even if the weight of the abrasive grains immersed in the plating solution is the same, the abrasive grains held per unit area on the tool surface by pre-processing not only the magnetic powder but also the abrasive grains By adjusting the weight of the abrasive grains immersed in the plating solution, the thickness of the plating film, and the grain size of the abrasive grains to be used, the density of the abrasive grains in the abrasive grain layer and the height of the abrasive grains are increased. The surface of the metal powder is coated with super-abrasive grains such as diamond and CBN or general abrasive grains such as WA, GC, and emery using electroless plating with a controlled grain size. The abrasive layer is formed only on the surface of the metal powder. , Preferably abrasive Are summarized as magnetic polishing tool arranged abrasive grain layer distributed tightly held uniform uniform protrusion amount.

Further, the present invention provides a magnetic polishing method characterized by using the above magnetic polishing tool.

The magnetic polishing of the inner surface of the alumina circular tube is performed, and in this case, the present invention provides a magnetic polishing method characterized in that the magnetic polishing of the inner surface of the alumina circular tube is performed by using the above magnetic polishing tool. And

In the present invention, a high-quality machined surface of about 0.3 μmRy is created by using the above-described magnetic polishing tool. The gist of the invention is a magnetic polishing method characterized by magnetically polishing the inner surface of a circular tube.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention uses a tool making technique which has not been employed in the manufacture of magnetic polishing tools until now, and has a uniform abrasive grain distribution, a uniform abrasive grain projection amount only on the magnetic powder surface. A tool provided with an abrasive layer having an excellent abrasive holding power was manufactured. High efficiency of magnetic polishing was achieved by the magnetic polishing method using this tool. An electroless plating method is employed for manufacturing the polishing tool of the present invention. At this time, in addition to the pretreatment (degreasing, surface activation, etc.) for the magnetic powder, the abrasive particles are also subjected to the pretreatment and mixed into the plating bath. According to this method, a tool in which abrasive grains are uniformly dispersed in a plating film having a uniform thickness and formed on the entire surface of a magnetic powder having a known particle size can be produced. Further, this tool has a uniform abrasive grain protrusion amount and has a sufficient abrasive grain holding force.

The magnetic powder used for producing the tool of the present invention includes:
A ferromagnetic metal material having a high magnetic permeability (a value indicating the degree of transmission of magnetic lines of force through an object) is used. Examples include cast iron, pure iron, pure nickel (non-metal), and iron-chromium alloy. The powder particle size is desirably 100 μm or more, and the shape is not limited.

As the abrasive used in the production of the tool of the present invention, a superabrasive such as diamond or CBN or a general abrasive such as WA, GC or emery is used. The average grain size is 5μ.
m or less.

No special equipment is required for manufacturing the tool of the present invention, and only equipment used is a constant temperature apparatus (row) and a plating bath used for controlling a plating bath temperature. For this reason,
Tool fabrication is possible with simple equipment and operation. Regarding the adjustment of each tool specification (a: abrasive grain density, b: abrasive grain protrusion amount and structure of abrasive grain layer), a: adjustment of the amount of abrasive grains mixed into the plating bath, b: film thickness of plating film Therefore, the tool specifications desired by the user can be set. Further, the tool produced by the present invention is a tool having uniform abrasive grain distribution, uniform abrasive grain protrusion, and excellent abrasive holding power, and has a processing pressure transmission and tool- All interference conditions of the workpiece can be solved.

A method for manufacturing a polishing tool will be described with reference to the drawings. FIG. 1 is a flow chart of tool production by electroless plating, and FIG. 2 is a schematic diagram of an electroless plating apparatus. The electroless plating solution is heated and maintained at a constant temperature. Next, magnetic powder such as spherical cast iron powder is washed with acetone and subjected to surface activation treatment with hydrochloric acid to pre-treat the magnetic powder. In addition, abrasive grains such as diamonds are immersed in a palladium ion solution, and palladium ion adsorption treatment is performed on the abrasive grains.
Pre-treat the abrasive. In the electroless plating, the pretreated magnetic powder and abrasive grains are placed in a plating bath, and the electroless plating is performed while maintaining the temperature at a constant temperature. After the plating treatment, washing and drying are performed to obtain a polishing tool. A polishing tool in which abrasive grains are held on the entire surface of a metal powder having a known particle size and shape can be manufactured.

An example of electroless plating conditions is shown below. Plating method Electroless plating Film composition Ni: 91.7%, P: 8.3% Plating bath temperature 70 to 75 ° C Processing time 15, 30, 60, 210, 300 min Metal powder Spherical cast iron powder 210 to 300 μm Abrasive diamond Grain [1 / 2-3 (central particle size 2 μm), 6-12 (central particle size 9 μm) Abrasive pretreatment palladium ion solution

The processing procedure includes (1) heating of a plating solution,
(2) Pretreatment of metal powder (pretreatment of abrasive grains: immersion in palladium ion solution), (3) immersion of metal powder and abrasive grains in plating bath, and (4) washing and drying after plating. The bath temperature is kept constant during the treatment, and the conditions differ, such as whether or not pre-treatment of the abrasive grains, the treatment time, the abrasive grain size to be used, etc.
Various kinds of tools were prototyped. As an example of a prototype tool, about 2
FIG. 3 shows a panoramic photograph of a prototype tool in which diamond abrasive grains of 6 to 12 μm are uniformly held on the surface of a 50 μm spherical cast iron powder.

Using the grinding tool of the present invention, the inner surface of an alumina circular tube was magnetically polished, and the polishing performance was evaluated. In addition, performance comparison with relatively frequently used simple mixed type magnetic abrasive grains,
The reusability of the prototype tool was also evaluated. An example of the processing conditions is shown below. Using magnet Fe-Nd-B permanent magnets work Grade (dimension) AL ₂ O ₃ (outer diameter 13 mm, inner diameter 9 mm) Tool electroless plating and polishing tool (the present invention) simple mixed magnetic abrasive grains (210～300Myuemu, Abrasive grain 1/2 / 3μm) Simple mixing type magnetic abrasive grain mixing ratio Abrasive grain / metal powder = 1/30 (weight ratio) Working fluid Water-soluble polishing fluid Filling amount of tool (powder) into tube 0.83g / cm ³ Lathe spindle speed 1250 rpm Feed in the pipe axis direction None Machining time 10 min In the magnetic polishing method, the tool (magnetic abrasive grains) is pressed against the machined surface by magnetic force to give relative motion between the tool and the work. proceed. A general-purpose lathe was used for processing, and the workpiece was fixed to the spindle. Fe ・ Nd ・
Using a B permanent magnet, it was fixed to the tool post with a jig. Processing was performed using these devices, and (1) comparison with simple mixed type magnetic abrasive grains, (2) the effects of abrasive grain size and plating film thickness on polishing performance, and (3) reuse of prototype tools were examined.

The state of holding the abrasive grains of the prototype tool is determined by the S
According to the EM observation photograph (FIG. 4), (a) the abrasive grain size is 1 / 2-
3 μm, no abrasive grain pretreatment, (b) abrasive grain size 1 / 2-3μ
m, abrasive grain pre-treatment, (c) abrasive grain diameter 6-12 μm, under any of the conditions of abrasive grain pre-treatment, regardless of the abrasive grain size used, the center grain of the grain size distribution width A particle size corresponding to the diameter is maintained. Also, photos (a),
From (b), even though the weight of the abrasive grains used in the plating process is the same, it is observed that the number of the abrasive grains held per unit area on the tool surface is increased by performing the pretreatment on the abrasive grains. Was done.

Regarding the evaluation of machining performance, a comparative test using a simple mixed type magnetic abrasive grain and a prototype tool (machining conditions: lathe spindle rotation speed 1250 rpm, tool filling amount into tube 0.83 g /
cm ³ , magnet-workpiece distance 0.5 mm, processing time 10
min) (final machined surface roughness) is shown below. Electroless plating / polishing tool (product of the present invention) 0.34 μmRy Simple mixed type magnetic abrasive grains (210 to 300 μm, abrasive grains 1/2 to 3 μm) 0.43 μmRy By using a prototype tool, surface roughness compared to simple mixing It was possible to reduce the length by about 0.8 times. It is considered that this is because holding the abrasive grains with the plating film made the abrasive grain protrusion amount uniform, thereby increasing the efficiency of processing pressure transmission.

Next, FIG. 5 shows the results of processing using a prototype tool in which the abrasive grain size and the plating film thickness are controlled. When the abrasive grain size is constant, the surface roughness decreases as the plating film thickness increases, but the difference is slight. On the other hand, the effect of the abrasive grain size on the surface roughness is large. When the abrasive grain size is −３-3 μm, the finished surface of 0.34 μm Ry is obtained as the best result, whereas the surface roughness at 6-12 μm is obtained. Is negligible. Here, in order to consider the relationship between the abrasive grain size and the polishing mechanism, SEM observation of the processed surface and measurement of the amount of work weight reduction with respect to the processing time were performed. FIG. 6 shows the change of the weight loss with respect to the processing time. Before processing (fired surface), abrasive grain size 1/2
According to the SEM photograph (FIG. 7) of the machined surface at −3 μm and the machined grain size of 6-12 μm (FIG. 7),
In the case of 3 μm, polishing streaks are observed over the entire surface, whereas in the case of 6 to 12 μm, fired surfaces (crystal grain boundaries) are observed in addition to the polishing streaks.

In FIG. 6, when the abrasive grain size is 1 / 2-3 μm, the weight loss increases with the elapse of the processing time, whereas when the abrasive particle size is 6-12 μm, the reduction does not change.
From these, it is inferred that when the abrasive particle diameter is 6 to 12 μm, material removal is not performed. Normally, the material removal mechanism of the constant pressure grinding process shifts up, excavates, and cuts as the processing pressure increases. When the abrasive particle size is 6-12 μm, 1
It is considered that the processing pressure did not reach the grinding start pressure under the magnetic field environment of the present test because the cutting edge angle became duller than / 2-3 μm. In addition, in any of the abrasive grain sizes, a weight reduction of 0.3 to 0.4 mg occurs in a processing time of 10 min, which is caused by initial destruction (wear) starting from a crystal grain boundary or the like on a fired surface. Conceivable. The above results suggest that the abrasive grain size used is an important factor that affects the polishing performance of the prototype tool, particularly the generation of the grinding start pressure.

The tool showing the best results in the processing test with respect to the state of holding the abrasive grains after machining and the reusability (abrasive grain diameter: 1 / 2-3 μm, film thickness / abrasive grain ratio = 2 .2), the possibility of reuse was examined. As a result, the performance gradually decreases as the number of processing increases, but 0.86
It was possible to obtain a finished surface of μmRy. In order to consider the cause of the performance degradation, SEM observation of the state of holding the abrasive grains in the prototype tool after machining was performed (FIG. 8). After processing, abrasive wear (micro crushing) and falling off have occurred,
These are considered to be the causes of performance degradation during reuse.

[0029]

In the electroless plating, a film (in the present embodiment, a film mainly composed of nickel and phosphorus) is formed on the surface of the metal powder. In the film forming process, the abrasive particles in contact with the cast iron powder are taken into the film, whereby the abrasive particles are mechanically held. The protrusion amount of the abrasive grains (the height from the plating film surface to the tip of the abrasive grains) can be controlled by changing the thickness of the film. Further, the number of abrasive grains held per unit area on the surface of the manufactured magnetic polishing tool can be controlled by the amount of abrasive grains immersed in the plating solution. In addition, even if the weight of the abrasive grains immersed in the plating solution is the same, it is confirmed that the number of abrasive grains per unit area increases on the tool surface by performing the pretreatment not only on the metal powder but also on the abrasive grains. did. In addition, the inner surface of the alumina tube was magnetically polished with a prototype tool.
It was possible to create a high-quality processed surface of Ry. As a result of studying the reuse of prototype tools, as the number of machining increases,
Although abrasive grain wear (fine crushing) and a decrease in the number of effective cutting edges due to abrasive drop-off occurred, the finished surface roughness slightly increased, but normal machining was possible.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to embodiments. The present invention is not limited by these examples.

Example 1 An example of a tool manufactured by electroless plating and its polishing performance are shown. (Production of Tool by Electroless Plating) (See FIGS. 1 and 2) The electroless plating solution is heated to 70 to 75 ° C. to prepare a plating bath. Next, 10 g of a spherical cast iron powder having a particle size distribution of 210 to 300 μm is subjected to a degreasing process with acetone and a surface activation treatment with hydrochloric acid (1N) to pre-treat the cast iron powder. Further, 10 g of diamond abrasive grains having a particle size distribution of −３-3 μm were immersed in a palladium ion solution, and the surface of the abrasive grains was subjected to a palladium ion adsorption treatment to prepare a pretreatment for the abrasive grains. The pretreated cast iron powder and abrasive grains were placed in a plating bath and subjected to electroless plating (1 hour). After the plating treatment, the sample is washed with water and dried to obtain a tool. The produced tool is a tool in which abrasive grains are uniformly held in a Ni-P coating of about 4.4 μm formed on cast iron powder, and the abrasive grains are held in a surface layer at a rate of 450,000 pieces per unit area. I have.

(Example of Magnetic Polishing Using Prepared Tool) Alumina ceramic tube (outer diameter 13 mm, inner diameter 9 mm,
The inner surface was magnetically polished before processing with a surface roughness of about 2.3 μmRy, and its polishing performance was evaluated. In addition, the performance was compared by using a simple mixed type magnetic abrasive grain from conventional tools.
Finished surface roughness obtained after processing for 10 minutes is: developed tool: 0.34 μmRy, simple mixed type magnetic abrasive: 0.4
It was 5 μmRy, and showed a polishing performance higher than that of a conventional tool. In addition, there is no contamination by wear debris on the machined surface with the developed tool.

[0033]

According to the present invention, a polishing tool using electroless plating is devised.
A prototype was fabricated and the performance was evaluated by magnetic polishing of the inner surface of the alumina tube, and the following findings were obtained. (1) By electroless plating, a polishing tool having performance equal to or higher than that of the simple mixed type magnetic abrasive grains can be produced. (2) The pretreatment of the abrasive grains has the effect of increasing the number of abrasive grains held on the prototype tool. (3) The prototype tool is a reusable tool having sufficient cutting ability even when reused. (4) The contamination of the machined surface due to wear debris of the magnetic powder, which occurs when using the simple mixed type magnetic abrasive grains, does not occur when using the prototype tool.

[Brief description of the drawings]

FIG. 1 is a flowchart of manufacturing a tool by electroless plating.

FIG. 2 is a schematic diagram of an electroless plating apparatus.

FIG. 3 is a panoramic view photograph of a prototype tool in which diamond abrasive grains are uniformly held on a surface of a spherical cast iron powder of about 250 μm instead of a drawing.

[Fig. 4] Abrasive grain retention state of prototype tool (film thickness / abrasive grain ratio = 2.
It is a SEM observation photograph which shows 2).

FIG. 5 is a drawing showing changes in abrasive grain size, plating film thickness, and surface roughness.

FIG. 6 is a diagram showing a transition of a work weight reduction amount with respect to a processing time.

FIG. 7 is an SEM of a machined surface using a prototype tool instead of a drawing.
It is an observation photograph.

FIG. 8 shows the state of holding the abrasive grains of the prototype tool after machining (abrasive grain diameter 1 /
4 is a SEM observation photograph instead of a drawing showing 2-3 μm, film thickness / abrasive particle diameter ratio = 2.2).

9A and 9B are schematic views of (a) a planar magnetic polishing method and (b) a circular pipe inner magnetic polishing method.

FIG. 10 is a view for explaining an interference state between a tool and a workpiece when a simple mixed type magnetic abrasive grain is used.

FIG. 11 is a drawing for explaining an apparatus of the plasma powder melting method.

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[Submission date] March 14, 2001 (2001.3.1.1)
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──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B24D 3/00 320 B24D 3/00 320B 3/06 3/06 B 3/34 3/34 Z (72) Inventor Yoshito Kondo 581-1 Goto-cho, Takamatsu City, Kagawa Prefecture F-term in the Kagawa Prefectural Industrial Technology Center 3C058 AA07 CA00 CB03 CB07 DA11 3C063 AA10 AB10 BB02 BB03 BC02 BG01 BG03 CC14 FF30

Claims (9)

[Claims] 1. A magnetic polishing tool in which an abrasive layer is disposed only on the surface of a magnetic powder. 2. The magnetic polishing tool according to claim 1, wherein the abrasive grains are firmly held with a uniform protrusion amount and are uniformly distributed. 3. The magnetic polishing tool according to claim 1, wherein abrasive grains are held on the surface of the magnetic powder using electroless plating. 4. An abrasive grain retained per unit area on a tool surface by pre-treating not only magnetic powder but also abrasive grains among electroless plating conditions, even if the weight of the abrasive grains immersed in a plating solution is the same. 4. The magnetic polishing tool according to claim 3, wherein the number is increased. 5. In the electroless plating, by adjusting the weight of the abrasive grains immersed in the plating solution, the thickness of the plating film, and the particle diameter of the abrasive grains used, the abrasive grain density and the abrasive grain protrusion height in the abrasive grain layer are adjusted. 4. The magnetic polishing tool according to claim 3, wherein the tool is adjusted. 6. The magnetic polishing tool according to claim 1, wherein the magnetic powder is a metal powder, and the abrasive grains are super-abrasive grains such as diamond and CBN or general abrasive grains such as WA, GC and emery. 7. A magnetic polishing method using the magnetic polishing tool according to claim 1. 8. The magnetic polishing method according to claim 7, wherein the inner surface of the alumina circular tube is magnetically polished. 9. The magnetic polishing method according to claim 7, wherein a high-quality processed surface of about 0.3 μm Ry is created.