JP2923440B2 - Flexible diamond coated abrasive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precision finishing tool which is used for polishing or grinding surfaces of relatively soft hard and brittle materials such as glass for lenses and other materials to be processed. Related to diamond-coated abrasive objects.

[0002]

2. Description of the Related Art Diamond abrasives are expected to have the best performance as a cutting edge of a precision finishing tool as a flexible abrasive object similar to abrasive cloth paper. This is because diamond is the material with the highest hardness compared to other abrasive grains (alumina alundum abrasive grains, silicon carbide-based carborundum abrasive grains, etc.), and is an ideal material for abrasive grains. It is. However, in order to use this as a painted and polished object, to have sufficient economical efficiency and to exhibit excellent practicality, the properties of diamond have not yet been sufficiently exhibited.

In a polishing process for a lens or the like, as a method of giving a desired surface shape to a workpiece, in a usual method, a tool itself is formed with a surface having a desired shape, and the workpiece is polished and ground on this surface. The method is adopted. However, in this case, when polishing or grinding a workpiece having a different surface shape, the tool has no flexibility, and it is necessary to reshape the surface each time. For that reason, it is important to give flexibility to the painted abrasive object,
It is conceivable to use this flexible painted abrasive object by attaching it to an abrasive object holder having a target shape surface,
Abrasive cloth is widely used as a flexible painted abrasive. In many cases, as the polishing cloth paper, a cloth or a polyester film having excellent flexibility is used as a substrate material, and a resin (for example, an epoxy resin) is mainly used as a binder material. In the case of abrasives that are far less expensive than diamond abrasives such as alumina-based alundum abrasives and silicon carbide-based carborundum abrasives, it is economical to use disposable materials using the above materials. Attractive enough. However, when diamond is used as abrasive grains, in such a combination, the strength of the substrate and the binder material is insufficient, the life is short, and the performance of the diamond cannot be sufficiently exhibited. Therefore, theoretically, high-strength painted and polished objects using a metal sheet as a substrate and metal as a binder material have been considered and proposed. In this method, one of the methods adopted to sufficiently bring out the performance of diamond abrasive grains is a method called electrodeposition bonding in which diamond abrasive grains are plated with a metal such as nickel on a metal sheet and fixed. In this method, the diamond abrasive grains are fixed to the substrate by plating, so that the holding power of the diamond abrasive grains is weak, and a product having expected performance has not been obtained.

In order to eliminate this defect, pure copper or 5%
Using a highly tough metal binder material made of a copper alloy containing a small amount of tin and having high wear resistance, a polished object with a structure in which diamond abrasive grains are fixed and held on a metal substrate by sintering was developed, and the polished object holding It is used for grinding and polishing hard and brittle materials such as lenses by being attached to a tool, and its use is expanding. However, even such a polished object is still insufficient in terms of life.

[0005]

As described above, in the conventional ordinary method, the tool itself is formed with a surface of a desired shape,
Grinding and polishing methods are used on this surface, but in this method, the tool itself does not have flexibility, so when grinding and grinding workpieces having different surface shapes, The surface must be reshaped each time. Considered to eliminate this drawback, a flexible material such as abrasive cloth using the above-mentioned flexible cloth or polyester film as a substrate material and mainly using a resin as a binder material was considered. Paint abrasive object having properties, alundum abrasive, even if it can be satisfied in the case of carborundum abrasive, when using diamond as abrasive, in such a combination,
The performance of diamond could not be fully exhibited.

In the electrodeposition bonding method proposed to fix diamond abrasive grains on a metal substrate by plating a metal such as nickel on the metal substrate, the diamond abrasive grains are fixed to the substrate by plating. In spite of the fact that the binder material is a tough metal, a product having the expected performance which is weaker in holding force of diamond abrasive grains than a metal bond fixed by sintering has not been obtained. Pure copper or 5 as described above, developed to eliminate this drawback
% Is still not sufficient in terms of life even for a polished object having a structure in which a diamond binder is fixedly held on a metal substrate by sintering using a metal binder material made of a copper alloy containing about% tin.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a flexible diamond-coated polished object having flexibility, high grinding and polishing ability, and long life. And

[0008]

Means for Solving the Problems The present invention has been completed as a result of extensive studies by the present inventors to achieve the above object. In other words, the flexible diamond-coated polished object of the present invention contains 20 to 30% by weight of tin on copper (20 times).
% Excluding 20% by weight but not more than 30% by weight
The metallic binder consisting of a copper alloy that has densified except pores therein with inclusion below with to form a diamond coating layer which is firmly held diamond abrasive grains on a flexible metallic substrate, said diamond The coating layer and the flexible metal substrate are integrated.

Such a flexible diamond-coated polished object according to the present invention comprises more than 30 % by weight of tin over 20 % by weight of copper.
A coating composition comprising a mixture of a metal binder made of a copper alloy and diamond abrasive grains contained below is coated on a flexible metal substrate to form a diamond coating layer, which is then sintered, and the metal binder is used. In addition to forming a diamond coating layer holding diamond abrasive grains firmly on a flexible metal substrate, integrating the diamond coating layer with the flexible metal substrate, and further increasing the density of the metal binder by applying pressure It is obtained by doing. On this occasion,
The coating composition can also be formed using a metal binder to which copper powder is further added. In this case, even if the tin content in the copper-tin alloy exceeds the above range, the tin content in the metal binder is increased from 20 % by weight to 30 % by weight by further adding copper powder. It can be set within the following range. The mixing ratio of the metal binder and diamond is not particularly limited, but is usually economically
About 5 parts by weight of diamond is used for 100 parts by weight of the metal binder.

As the material of the flexible metal substrate in the present invention, a copper plate and a steel plate are the most preferable materials in view of strength, economy, excellent workability, and large elongation. Furthermore, it is preferable to select a thickness of the substrate in order to give the coated abrasive object a preferable performance and facilitate the adaptation to the surface of the abrasive object holder, and to have a thickness in the range of 0.05 to 0.20 mm. . If the thickness is more than this range, it is difficult to attach, and if it is too thin, it is difficult to fulfill the role of the substrate.

The metal binder used in the present invention is:
It is a copper alloy containing more than 20 % tin and 30% or less .
A copper-tin alloy having a tin content of up to 14% is easily deformed because of a uniform structure called a copper α solid solution and good workability. However, when the tin content exceeds 14%, the tin content is increased to 20 to 30.
%, An intermetallic compound represented by a chemical formula of Cu ₄ Sn called δ appears and has a structure of (α + δ), and the hardness is remarkably hardened to Vickers hardness of 200 to 300.
Therefore, by coating a coating composition comprising a metal binder having the above-mentioned tin content and diamond abrasive grains on a flexible metal substrate and then sintering, a strong diamond abrasive grain by sintering of the metal binder is obtained. The diamond abrasive grains are firmly fixed and held on the metal substrate by both the holding force and the bonding force to the substrate, and an integrated painted abrasive body is obtained.

In other words, when the coating composition comprising the mixture of the metal binder and the diamond abrasive is coated on the flexible metal substrate and then sintered, the coating composition is solidified by sintering. At the same time, the metal substrate is subjected to diffusion bonding through a metallurgical process, and the two are integrated to obtain a painted polished object. In this sintering process, in order to prevent the deterioration of the abrasive performance due to the graphitization of the diamond abrasive, 600 to 80
Heat and hold for a short time (10 to 30 minutes) in a temperature range of 0 ° C. The atmosphere of the sintering is an atmosphere of a reducing gas such as a hydrogen gas having a low dew point and a decomposed ammonia gas comprising nitrogen and hydrogen in a ratio of about 1: 3 in order to prevent oxidation of the metal powder and promote diffusion. Use

In this sintering process, excessive diffusion of the copper or tin of the metal binder component into the substrate lowers the elongation and embrittlement of the substrate and reduces the flexibility of the polished object. Therefore, the sintering temperature is kept at a lower temperature of 600 to 800 ° C., and the sintering time is kept short within 30 minutes. When using a copper-tin alloy as a metal binder, a mixed powder of copper and tin (tin exceeding 20 % by weight and 30 % by weight
When the following is used, a large amount of liquid tin (melting point: 232 ° C.) generated in the sintering process promotes the diffusion of tin or copper into the substrate. In order to prevent this phenomenon, it is preferable to use an alloy powder of copper and tin instead of using the mixed powder as described above.

Further, when the metal substrate is a copper plate, a pure copper plate is selected to prevent the tin content from increasing due to diffusion during sintering, and the tin content in the substrate is kept at a maximum of 14% or less so that the substrate is brittle. Can be prevented. Further, when the metal substrate is a steel plate, tin plating (5 to 10 μm thickness) is applied, or the carbon content in the steel plate is reduced to 0.2% or less,
It is possible to prevent the substrate from being embrittled by the diffusion of copper into the steel sheet.

In order to apply a coating composition comprising a mixed powder of diamond abrasive grains and a metal binder on a flexible metal substrate, an adhesive called a primary binder is mixed with the coating composition and the adhesive is applied. It is preferable to form a uniform coating film that is in close contact with the substrate by utilizing the properties of the film. Then, it is necessary to decompose and remove the primary binder by heating at a stage prior to the sintering process. As a preferable method for this purpose, an adhesive obtained by dissolving an organic binder (polyvinyl alcohol, arabia rubber, natural rubber, cellulose, polyvinyl butyrate, polymethyl methacrylate resin, etc.) in an organic solvent such as isopropyl alcohol, for example, Coating composition 1 as resin
It is added so as to be 5 to 10 parts by weight with respect to 00 parts by weight,
Further, the amount of isopropyl alcohol is adjusted, and the paste is applied on a flexible metal substrate as a paste composition having a viscosity (2.0 poise or less) suitable for brush coating. The solvent is evaporated from the paste composition applied to the metal substrate, and it is necessary to remove the primary binder from the dried and solidified coating layer without deteriorating the strength of the coating or peeling the coating from the metal substrate. There is. This is usually performed by heating in a protective atmosphere such as a nitrogen gas atmosphere. Depending on the type of primary binder, a temperature between 300 and 500C is chosen. In some cases, depending on the type of the primary binder, a method of heating at a temperature of 200 to 400 ° C., preferably at a temperature of 300 ° C. in an oxidizing atmosphere, for example, in the air, and removing the primary binder by incineration is adopted. You may.

As another method of coating a coating composition comprising a mixed powder of diamond abrasive grains and a metal binder on a flexible metal substrate, for example, the coating composition may be applied from a powder supply end on a funnel to While applying vibration, on the metal substrate surface,
Spray so as to form a uniform powder layer, and furthermore, in order to ensure the uniformity of the thickness of the scatter layer, smooth the scatter layer with a roller and apply a powder layer with the uniform thickness as possible on the metal substrate. There is a powder roll rolling method.

In order to further assure the performance of the polished diamond-coated diamond object of the present invention, the sintering process is followed by a densification treatment of the metal binder in the coating layer. The remaining holes are removed. This processing is performed when the metal substrate is a copper plate.
In a temperature range of 600 ° C., a so-called boudouard reaction equilibrium gas mixture of three components of nitrogen, carbon monoxide, and carbon dioxide obtained by slowly flowing air through a carbon layer, a non-oxidizing gas such as a nitrogen gas atmosphere. It is preferable to carry out the treatment for several minutes under an applied pressure of 100 to 500 kgf / cm ^{2 in} an atmosphere while preventing oxidation. In addition, when a metal substrate is a steel plate, 450-
The high-density treatment can be performed in the temperature range of 650 ° C. in the same manner as in the case of the copper substrate.

Further, this high-density treatment is performed for 500 to 60
The molten tin may be impregnated with the metal binder in a reducing atmosphere at 0 ° C., and then subjected to a tin diffusion treatment by heating at 600 to 700 ° C. Can be achieved. In the final stage of the densification, 5 to 7 ton /
It is preferable to apply a re-pressurizing force of ² cm ² to uniformize the performance of the painted abrasive and improve the dimensional accuracy.

[0019]

Since the metal substrate according to the present invention is flexible, the coated and polished object of the present invention is also flexible. The painted abrasive object of the present invention can be applied to a surface-shaped tool to create a required surface shape.

In the present invention, the metal binder contains 20 %.
A copper alloy containing 30% or less of tin Beyond, Cu
And δ is represented by the chemical formula ₄ Sn and a phase of an intermetallic compound called copper in a two-phase structure of the α-phase having excellent the toughness mainly the hardness significantly strong hard 200 to 300 in Vickers hardness Material. This material is solidified by sintering, and the diamond abrasive grains in the painted abrasive body of the present invention are firmly retained by the metal binder which has been densified by applying pressure in order to remove remaining pores as much as possible. Is firmly bonded to the metal substrate. At the sintering temperature, constituent metal atoms are diffused between a metal binder, which is a copper alloy containing more than 20 % and 30% or less of tin, and a metal substrate, and both are metallurgically bonded. Is done. In addition, the metal binder itself is actively diffused inside, and solidification proceeds. The result is a strong and integrated painted and polished object of the present invention.

As described above, the metal binder filling the space between the diamond abrasive grains has a strong two-phase structure and a high-density hard structure with few voids. Resists the force received by the surface and holds the abrasive grains strongly, and has excellent abrasion resistance and resistance to abrasive wear (abrasive wear) caused by polishing debris formed from hard and brittle materials such as glass as the mating material. Is big. Therefore, in the painted abrasive body of the present invention,
When the diamond abrasive grains are repeatedly subjected to grinding and polishing force, the metal binder gradually deforms, and as a result, the pressing of the diamond abrasive grains by the binder is loosened, and the phenomenon that the diamond abrasive grains finally fall off, so-called dropping phenomenon, is prevented. In addition, the life of the painted abrasive body is kept long.

As described above, the metal binder in the present invention is a structure containing a large amount of the intermetallic compound represented by the chemical formula of Cu ₄ Sn, and has a nonmetallic property rather than a metallic property. Extremely hard. For this reason, a phenomenon in which polishing debris formed by polishing the mating surface adheres to the metal binder portion, sinks, and accumulates, that is, a so-called clogging phenomenon is prevented. That is, in the painted abrasive article of the present invention, the gap between the diamond abrasive grains is filled with the polishing debris, the projected exposed portion of the diamond abrasive grains is less likely to be reduced, and the grinding and polishing ability of the painted abrasive article is not reduced, and the efficiency is improved. Grinding and polishing can proceed.

Further, the metal binder has a dense structure with a small number of pores and a high density, is hardly deformed, and has a large elastic modulus. Therefore, in the painted abrasive body of the present invention,
The support rigidity of diamond abrasive grains is large, and the deformation of the painted abrasive object during processing is suppressed to a minimum (the phenomenon that the abrasive object recedes from the contact surface due to deformation, so-called escape phenomenon is prevented), and the uncut amount decreases .

[0024]

【Example】

Example 1 80 parts by weight of a copper alloy powder of 200 mesh or less containing 30% by weight of tin (containing 40% by weight or more of fine powder of 325 mesh or less) and 20 parts by weight of fine electrolytic copper powder having an average particle diameter of 5 μm or less And 5 parts by weight of a 1000-mesh synthetic diamond powder was added to the resulting mixed powder metal binder and dispersed and mixed to obtain a coating composition (tin content 24% by weight in the metal binder of the coating film). ).

A primary binder obtained by dissolving a polymethyl methacrylate resin in isopropyl alcohol is added to 100 parts by weight of the above-mentioned coating composition so as to have a resin content of 5 parts by weight, and the amount of isopropyl alcohol is further adjusted. Thus, a paste composition having a viscosity suitable for brush coating (2.0 poise or less) was obtained.

Prior to applying the paste composition to the copper substrate, various foreign substances formed on or adhered to the surface of the copper substrate were removed in order to secure a strong bond between the copper substrate and the metal binder. . Removal of foreign matter on the surface of the metal substrate, removal of metal oxides and dust, etc., by sandblasting or wire brushing, finally,
Removal of deposits of fats and oils was performed using an organic solvent to obtain a copper substrate having a chemically clean surface.

The paste-like composition described above is applied to the surface of the thus-purified flexible copper substrate having a thickness of 0.1 mm.
The primary binder was incinerated and removed by heating in air at 00 ° C. Next, the copper substrate coated with the coating composition was heated at 700 ° C. for 30 minutes in a reducing gas atmosphere and sintered. As the reducing gas, a low-dew-point hydrogen gas filled in a commercially available high-pressure gas cylinder was used. The sintered product is further
300 kgf / cm ^{2 at} a temperature of 00 ° C. in a non-oxidizing atmosphere (a so-called Boudouard reaction equilibrium gas atmosphere of a three-component mixture of nitrogen, carbon monoxide gas and carbon dioxide gas obtained by slowly flowing air through a carbon layer). , And maintained for several minutes. The pores remaining in the coating layer even after sintering were almost completely removed to perform a high-density treatment. Finally, in order to make the performance uniform and improve the dimensional accuracy, 5 to 7 ton / cm
^Then , re-pressurization was applied, and the sample was annealed by heating at 600 ° C. for 30 minutes while preventing oxidation in the above Boudouard reaction equilibrium gas atmosphere to obtain a flexible diamond-coated polished object of the present invention.

A disk-shaped sheet having an outer diameter of 80 mmφ is cut out from the obtained flexible diamond-coated polished object.
This was affixed on a lap plate and used for polishing a lens material (commercially available lead glass SF-6 material) having an outer diameter of 70 mmφ. For comparison, a commercially available metal-bonded product (copper-bonded product) was cut into a disk-shaped sheet having an outer diameter of 80 mmφ in the same manner as in the case of the painted abrasive article of the present invention, and subjected to a polishing test under the same conditions. Using each of the product of the present invention and a commercially available product for comparison, the removal amount (μm) of the lens material per minute and the presence / absence of scratches per minute with the lapse of polishing time were tested. The results are shown in Table 1 below.

[0029]

[Table 1]

Based on the results of the comparative tests in Table 1 above, the points of improvement of the product of the present invention as compared with commercial products are as follows. That is, while the total removal amount of the lens material by the commercial product is 473 μm, the total removal amount of the lens material by the present invention is 676 μm, and the removal amount by the present product is about 40% as compared with the commercial product. The removal amount increased.

Further, the amount of removal per minute of a commercially available product is a minimum of 27 μm and a maximum of 77 μm (range is 50 μm), and the amount of removal per minute is large. Therefore, the variation in the polishing operation is large. Is unstable. On the other hand, in the case of the product of the present invention, the removal amount per minute is a minimum of 63 μm and a maximum of 72 μm (range is 9 μm).
m), with less variation, uniform polishing,
Polishing work can be performed stably.

Further, in the case of a commercially available product, scratches occur after about 6 minutes have elapsed, and it is meaningless to continue polishing for 10 minutes or more. With the product of the present invention, no scratch was generated even after 10 minutes had elapsed, and further continuous polishing was possible, prolonging the life.

Example 2 A flexible tin-plated steel sheet having a thickness of 0.1 mm (tin-plated layer having a thickness of 7.5 μm and a carbon content of 0.2% or less) was used as a metal substrate. 80 parts by weight of copper-tin alloy powder of 200 mesh or less containing 35% by weight of tin (containing 40% by weight or more of fine powder of 325 mesh or less) 20 parts by weight of reduced copper powder of 5 μm or less and synthetic diamond powder of 600 mesh A mixture consisting of 5 parts by weight was used (tin content 28% by weight in the metal binder of the coating). The tin-plated steel sheet is cleaned with an organic solvent to remove dust, greasy deposits, etc. on the surface.
The one kept chemically clean was used.

The above coating composition was sprayed from the funnel-shaped powder supply end onto the substrate surface while applying vibration so as to form a uniform powder layer. Furthermore, in order to ensure the uniformity of the thickness of the spraying layer, a hardened steel roller with a smooth surface (Rockwell C scale) of 60 or more with a smooth surface is used, and a layer with a thickness as uniform as possible is formed. Formed on steel plate.

Next, the steel sheet coated with the coating composition is sintered by heating at 800 ° C. for 10 minutes in a reducing ammonia gas atmosphere in which N ₂ and H ₂ are in a ratio of about 1: 3. did. In this sintering process, the sintering of the metal binder phase, which is a main component of the coating composition, is promoted, and at the same time, the joining between the individual metal powders constituting the metal binder phase and the steel sheet with the help of molten tin on the steel sheet. We were able to be strong.

Further, in order to carry out the treatment for increasing the density of the metal binder, the sintered product is placed in a non-oxidizing protective atmosphere (dry nitrogen gas atmosphere provided by a commercially available high-pressure gas cylinder) while preventing oxidation. It was compacted by a roll at a temperature of ° C. The pressing force used for compaction by a roll is 350 kgf / cm ² , and the pores remaining in the coating layer are crushed by this pressurization, and the density of the coating layer and the substrate are increased almost 100%. Perfect bonding is achieved,
A flexible diamond-coated abrasive body was obtained in which the diamond abrasive grains were firmly held by the metal binder and were completely integrated.

As in Example 1, a disk-shaped sheet having an outer diameter of 80 mm was obtained from the polished diamond coated object obtained as described above, and this was affixed to a lap plate to form a nitride, which is a typical material of fine ceramics. Grinding of silicon (Si ₃ N ₄ ) ceramics was performed. For comparison, a disk-shaped sheet made of commercially available silicon carbide abrasive grains (particle size: 600 mesh) was also ground under the same conditions.

With respect to the case of using each of the product of the present invention and the commercially available silicon carbide sheet, the removal amount (μm) of the silicon nitride ceramics was measured every two minutes with the passage of the grinding time, and the results are shown in Table 2 below. Indicated.

[0039]

[Table 2] Notes 1) and 2): Removal amount of silicon nitride ceramics per minute (μm) As is clear from the results shown in Table 2 above, in the case of a sheet made of silicon carbide abrasive grains for comparison, the removal rate was 2 minutes. The average value of the amount removed was as small as 4.7 μm. On the other hand, in the case of the flexible diamond-coated polished object of the present invention, the average value of the removal amount per 2 minutes is 21 μm, which is nearly four times that of the comparative product, and has excellent grinding ability. there were.

[0040]

Since the flexible diamond-coated polished object of the present invention is flexible, if it is used by attaching it to a holder having a target shape surface, the tool itself has a target shape surface. There is no need to reshape the tool surface each time as in the case of the related art in which is formed. In addition, unlike a conventional flexible painted abrasive object that is formed by using a cloth or a plastic film as a substrate and using a resin as a binder for abrasive grains, the painted abrasive object of the present invention uses a metal sheet as a flexible substrate. Since the metal is used as a binder, a solid painted abrasive body is one that is given flexibility,
Therefore, according to the present invention, a long-life, high-efficiency painted abrasive object suitable for diamond abrasive grains is put to practical use.

When the coated and polished object of the present invention is pasted as a disk-shaped sheet on a lap plate and lap-polishing of lenses and ceramics is performed, there is no so-called dropping or clogging. The amount can be maintained and secured over a long period of time. That is, compared with a coated abrasive using only a copper or a metal binder containing 5% or less of tin, the coated abrasive of the present invention can extend the service life by several times to more than 10 times. it can.

Since the coated abrasive of the present invention has no abrasive grains falling off (spills), scratches on the polished surface due to the dropped abrasive grains can be prevented over a long period of use. The occurrence of scratches makes it impossible to achieve the purpose of polishing, which is a fatal defect of the polishing tool. However, in the painted polishing object of the present invention, the occurrence of this trouble is strongly prevented.
This is also evident from the results shown in Table 1 above in Example 1. In the coated and polished object of the present invention, a good polished surface that can withstand long-term use is obtained.

Although the coated and polished object of the present invention was originally developed for the purpose of final polishing of a lens, the feature that diamond abrasive grains are strongly held by a strong metal binder is that even when the abrasive grains are enlarged, Sufficiently exerted and exerts a sufficient effect not only on polishing but also on grinding. That is, the coated abrasive object of the present invention can be subjected to high-speed rotational motion to perform belt grinding, for example, as a so-called diamond belt joined in an endless belt shape. And since it is more flexible than a diamond wheel, flexibility can be imparted, and cracks and chips can be prevented when grinding a brittle material such as ceramics. Therefore, the coated and polished object of the present invention can be widely used in the fields of chamfering glass, centering a lens, and grinding marble.

Silicon nitride (Si ₃ N), a fine ceramics product, which is difficult to grind with general silicon carbide abrasive grains
₄ ) In contrast to the quality ceramics, the diamond-coated polished object of the present invention has a removal ability and enables grinding. That is, in the above-mentioned Example 2, the result of applying the coated abrasive object of the present invention as a disk-shaped sheet on a lap plate and grinding the silicon nitride was as follows. It shows that it has sufficient grinding ability.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B24D 11/00 B24D 3/00 310 B24D 3/00 320 B24D 3/08

Claims (2)

(57) [Claims] 1. A method according to claim 1, wherein tin is added to copper in an amount of 20 to 30 wt% (20 wt%
The metallic binder consisting excluding) copper alloy is densified except pores therein with inclusion, together to form a diamond coating layer which is firmly held diamond abrasive grains on a flexible metal substrate, A flexible diamond-coated polished object obtained by integrating the diamond-coated layer and the flexible metal substrate. 2. The flexible metal substrate has a thickness of 0.05 to 0.5.
The flexible diamond-coated polished object according to claim 1, which is 20 mm.