JPH10193268A - Manufacture of super abrasive grain metal bond grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a super abrasive grain metal bon grinding wheel by which nonuniformity of density is reduced and which is excellent in uniformity of the abrasive grain distribution and has excellent grinding power in a small abrasion quantity by preparing slurry containing super abrasive grains and metallic powder, and molding this slurry into a plate shape. SOLUTION: When grinding wheel raw material slurry is prepared, for example, slurry containing abrasive grains, metallic powder, a water soluble resin binding agent, a surfactant, a plasticizer, water or the like is prepared by a slurry mixer or the like. The prepared slurry is molded into a plate shape. A molded body molded in a plate shape by a doctor blade or the like is dried. Next, the obtained dry molded body is worked in a prescribed shape. It is desirable tat backing is performed by sandwiching the dry molded body by a base board composed of a thermally stable and metallic fusion uncasusable raw material such as carbon graphite and ceramics in order to prevent deformation of the dry molded body in a degreasing-sintering process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a superabrasive metal bond grindstone applicable to a wide range of grinding and cutting such as grinding of difficult-to-cut materials such as ceramics and glass or steel.

[0002]

2. Description of the Related Art Metal sintering containing diamond or cBN as abrasive grains is used for grinding or cutting a work such as difficult-to-cut materials such as ceramics and glass, steel materials, or various building materials such as concrete blocks. As a method of manufacturing a super-abrasive metal bond whetstone consisting of a body,
Conventionally, there is the following powder molding method. For example, FIG.
As shown in (A) and (B), an outer frame die 201, an inner frame die 202 that fits inside thereof, and a lower punch 204 and an upper punch slidably inserted into a gap between these dies. A mixed powder 210 of metal powder and abrasive grains is put in a ring-shaped gap constituted by 203 and pressed (cold press) to obtain a ring-shaped compact, which is sintered and shown in FIG. The ring-shaped sintered wheel 211 is manufactured as described above,
11 is adhered to the outer periphery of the disk-shaped base metal 212, and FIG.
A super-abrasive grindstone 213 as shown in FIGS.

[0003]

However, in the conventional powder molding as described above, since the powders are mixed in a dry manner,
Mixing unevenness of abrasive grains and metal powders occurs, and powder molding causes density unevenness at the time of filling the mixed powders, and it is difficult to manufacture a grinding wheel having excellent grinding power and low wear characteristics of itself. there were. In addition, the mold for the cold press was greatly consumed, which led to an increase in manufacturing cost.

[0004] The present invention has been made in view of such circumstances, has low density unevenness, and has excellent uniformity of abrasive grain distribution.
An object of the present invention is to provide a manufacturing method capable of providing a superabrasive metal bond wheel having excellent grinding force with a small amount of wear at a low cost.

[0005]

In order to achieve the above-mentioned object, the present invention provides a slurry containing superabrasive grains and a metal powder, and forms the slurry into a plate-like shape. The method for producing a super-abrasive metal bond grindstone is characterized in that a super-abrasive metal-bonded grindstone is processed and then fired.

[0006] As a method of forming the slurry into a plate shape,
Doctor blades are preferred. In the present invention, the above-mentioned slurry contains 5-45 vol.
% By volume, and 95 to 55% by volume of an organic binder aqueous solution.
It is desirable to contain 5 to 20% by weight, 0.5 to 3% by weight of a surfactant, and 0.1 to 15% by weight of a plasticizer.

[0007]

According to the method for producing a superabrasive metal bond grindstone of the present invention, a superabrasive and a metal powder as a binder component are mixed together with a liquid medium or the like in a slurry form, and after the slurry is formed into a plate form, Process into a shape and sinter. By suspending and dispersing the abrasive grains and the metal powder in the liquid medium in this way, it is possible to prevent the aggregation of the abrasive grains and the like and to suppress the density unevenness. Further, by sufficiently kneading the slurry, the density unevenness and the thickness are reduced. Can be suppressed. In particular, uneven distribution of the abrasive grains is suppressed to a low level, so that it is possible to suppress uneven wear, chipping, and the like of the obtained superabrasive stone, and to obtain uniform characteristics. As a result, the amount of wear is small. Thus, a superabrasive metal bond wheel having excellent grinding power can be manufactured.

In addition, a doctor blade is suitable for forming a slurry into a plate shape, and a mold for cold press which is frequently used in the conventional powder molding process is not used, which is economically advantageous. It is. In order to effectively disperse the abrasive grains and the metal powder by the wet method, and to form the slurry and maintain the shape after the slurry is formed, 2.5 to 50% by volume of super-abrasive grains as a component of the slurry, Of the sintered mixed powder containing 97.5 to 50% by volume of
5% by volume, 95 to 55% by volume of an organic binder aqueous solution, the organic binder aqueous solution containing 0.5 to 20% by weight of a water-soluble resin binder and 0.05 to 3% by weight of a surfactant
In order to improve the processability of the molded article after drying, it is preferable to contain 0.1 to 15% by weight of a plasticizer. Organic binders such as these water-soluble resin binders disappear by firing.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. The superabrasive metal bond grindstone of the present invention can be produced by, for example, a grindstone raw material slurry preparation step, a forming step, a drying step, a press cutting step, a shape processing step, a degreasing step, a sintering step, a base metal attaching step, and the like. .

First, the preparation of a slurry for a grindstone raw material involves preparing a slurry containing, for example, abrasive grains, metal powder, a water-soluble resin binder, a surfactant, a plasticizer, water and the like using a slurry mixer or the like. As the abrasive grains, for example, diamond grains, cBN grains, and the like are used, but the abrasive grains are not limited to these. The grain size of the abrasive grains is not particularly limited, and is appropriately selected according to the intended use of the superabrasive grain to be obtained. For example, a grain size of about 5 to 30 μm for precision machining. Is used.

The type of the metal powder is not particularly limited as long as it can be sintered at a temperature lower than the melting point of the abrasive grains. For example, sintering of tin, lead, copper, nickel, iron, cobalt, chromium, etc. All metals and alloys that can be used. The average particle diameter of the metal powder is 500 μm or less, especially 0.5 to
A range of 100 μm is preferred. When the average particle size is smaller than 0.5 μm, there is a risk of reacting with water at the time of preparing the slurry and igniting. On the other hand, when the average particle size is larger than 500 μm, the strength of the resulting superabrasive grindstone may be too weak. .

The mixing ratio of the abrasive grains to the metal powder is such that the abrasive grains are in the range of 2.5 to 50% by volume, particularly 10 to 25% by volume, based on the total amount of the abrasive particles and the metal powder (sintered mixed powder). 9 powder
A range of 7.5 to 50% by volume, particularly 90 to 75% by volume is desirable. If the amount of the abrasive grains is smaller than this range, the polishing performance may be inferior. If the amount is too large, the strength of the formed body may be insufficient and processing into a predetermined shape may be difficult.

The total amount of these abrasive grains and metal powder in the slurry (sintered mixed powder) is 5 to 45.
The volume ratio is preferably in the range of 20 to 35% by volume, and the aqueous solution of the organic binder as the aqueous solution component of the slurry is preferably in the range of 95 to 55% by volume, particularly preferably in the range of 80 to 65%. If the amount of the sintered mixed powder in the slurry is too large,
If the viscosity increases, the moldability deteriorates and it may not be possible to mold into a plate.If the amount is too small, the density of the powder after debinding decreases, the shape collapses, the powder becomes powdery, and a sintered body is obtained. May not be possible.

The water-soluble resin binder has a function of maintaining the shape of the plate-like molded product when the slurry is dried.
It also functions as a viscosity modifier for the slurry. Examples of the water-soluble resin binder include methylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, carboxymethylcellulose ammonium, ethylcellulose, polyvinyl alcohol and the like. The compounding amount of the water-soluble resin binder is preferably in the range of 0.5 to 20% by weight, particularly 2 to 10% by weight in the aqueous organic binder solution. If the amount is less than 0.5% by weight,
The strength of the dried molded article is low, which may hinder handling. On the other hand, if it is more than 20% by weight, the viscosity may be too high and molding may be difficult.

The surfactant has the effect of improving the dispersion stability of the abrasive grains and metal powder in the liquid medium, and the effect of adding a foaming agent to stabilize the foaming state and forming micelles of the foaming agent. Surfactants include alkyl benzene sulfonates, α-olefin sulfonates, alkyl sulfates, alkyl ether sulfates,
Examples thereof include anionic surfactants such as alkane sulfonates, and nonionic surfactants such as polyethylene glycol derivatives and polyhydric alcohol derivatives. The amount of the surfactant is 0.05% in the organic binder aqueous solution.
The range is preferably from 5 to 5% by weight, particularly preferably from 0.5 to 3% by weight.
If the amount is less than 0.05% by weight, the dispersion stability of the abrasive grains and metal powder cannot be improved, and the formation of micelles becomes unstable, making it difficult to keep fine bubbles. On the other hand, if it is more than 5% by weight, no further effect may be obtained.

[0016] In addition to the above components, a plasticizer can be added to the raw material slurry of the present invention. The plasticizer is for imparting plasticity to the molded article, and can prevent cracks and the like during deformation processing such as winding of the dried molded article. Examples of the plasticizer include polyhydric alcohols such as ethylene glycol, polyethylene glycol, and glycerin, oils such as sardine oil, rapeseed oil, and olive oil, ethers such as petroleum ether, diethyl phthalate, di-n-butyl phthalate, and diethylhexyl phthalate. And esters such as dioctyl phthalate, sorbitan monooleate, sorbitan trioleate, sorbitan palmitate and sorbitan stearate. The amount of the plasticizer is 0.1 to 1 in the aqueous organic binder solution.
A range of 5% by weight, especially 2-10% by weight is preferred. If the amount is less than 0.1% by weight, the plasticization may be insufficient, while if it is more than 15% by weight, the strength of the molded article may be insufficient.

A foaming agent can be added to the slurry in order to obtain a porous superabrasive wheel suitable for the intended use.
After adding the foaming agent to the slurry in this way and forming it into a plate shape by a doctor blade, the foaming agent is foamed to form bubbles in the slurry. Therefore, it is possible to prevent the abrasive grains and the metal powder from sedimenting and causing density unevenness inside the molded body. Then, when this is dried, it solidifies while maintaining the shape of the bubbles together with the water-soluble resin binder (binder).
When this is fired, the binder disappears and the metal powders sinter together to obtain a superabrasive grindstone having a foamed three-dimensional network structure having a bubble shape. When the superabrasive grindstone has a porous structure in this way, it is possible to reduce the grinding resistance between the obtained superabrasive grindstone and the object to be ground. Lubricant retention is improved. The porous structure can be arbitrarily controlled by the pressure, temperature conditions, and the like during sintering.

The foaming agent may be any compound as long as it can generate gas to form gas bubbles. A compound which decomposes at a certain temperature to generate gas and a volatile organic solvent can be selected. As a volatile organic solvent, for example, carbon number 5
8 hydrocarbon-based organic solvents. Such an organic solvent is liquid at room temperature, is volatile, forms micelles in a slurry by the action of a surfactant, and vaporizes at room temperature or under heating to form fine bubbles. Carbon number 5
Examples of the hydrocarbon organic solvent of Nos. To 8 include pentane,
Neopentane, hexane, isohexane, isoheptane, benzene, octane, toluene and the like can be mentioned. The compounding amount of the foaming agent is as follows:
The range is preferably 0.05 to 10% by weight, particularly 0.5 to 5% by weight. If the amount is less than 0.05% by weight, the generation of bubbles may be insufficient and the porosity may not be increased. On the other hand, if the amount is more than 10% by weight, the size of the micelles may increase. Since the diameter of the bubbles formed in the compact also increases, the strength of the resulting compact and sintered compact may decrease. In addition, instead of using a foaming agent, it is also possible to adjust the grindstone raw material slurry by a method of vigorously mixing a gas such as air.

The raw material slurry of the present invention can be obtained by mixing the above components. In this case, the order of mixing is not limited, but when using a blowing agent as described above, it is preferable to mix the blowing agent last in order to limit foaming as much as possible during mixing. The viscosity of the slurry is 5000 cps to 70000 cp at 20 ° C.
The range of s, in particular, the range of 10,000 to 30,000 cps is preferable. If the viscosity is lower than 5000 cps, a molded article having a predetermined thickness may not be obtained.
If the viscosity is higher than 0 cps, the viscosity may be too large and molding may be difficult.

Next, the slurry thus prepared is formed into a plate. The molding method is not particularly limited, but a doctor blade method is suitable. Doctor blade gap,
That is, the thickness of the plate-like molded body is preferably about 0.1 to 3 mm. As the doctor blade, two-blade blades 60A and 60B as shown in FIG. 11 can be used. The reason for this is that, as shown in FIG. 11, when two blades 60A and 60B are used, large air bubbles B are removed from the gap between these blades, and the plate-shaped molding extruded from the gap between the second blade 60B. This is because large bubbles do not enter the body 1A and the thickness of the formed body can be made uniform regardless of the level of the liquid surface of the grindstone raw material slurry S. in this case,
The gap G1 between the cutting edges of the first first blade 60A is
It is preferable that the gap be larger than the gap G2 of the cutting edge of the blade 60B. Also, the first blade 60A and the second blade 6
The gap D of 0B is preferably, for example, about 5 to 20 mm.

When a foaming agent is added to the slurry as required to form a foamable slurry, it is preferable to provide a foaming step before drying the plate-like molded body. When dried immediately after molding, the surface of the molded body is dried first to form a skin, and foaming and evaporation of water inside the molded body are prevented, and foaming may be uneven.

When foaming is performed simultaneously with foaming, cracks are likely to occur on the surface of the molded article. Therefore, it is preferable to perform foaming in a high-humidity atmosphere in order to prevent drying as much as possible during foaming. Specifically, the humidity is at least 65%, preferably at least 80%. If the humidity is lower than 65%, cracks may be formed on the surface of the molded body during drying. The foaming temperature is preferably in the range of 15 to 65 ° C, particularly preferably in the range of 28 to 40 ° C. If the foaming temperature is lower than 15 ° C., foaming may take, for example, 2 hours or more, and if it exceeds 65 ° C., the molded body may be excessively foamed and collapsed. The foaming time is usually 10
範 囲 45 minutes.

Next, the molded body formed into a plate shape with a doctor blade or the like or the molded body after the foaming step is dried. Drying can be carried out by natural drying, for example, by leaving it to stand for several hours or half a day. Also, forced drying can be performed using a dryer. For the forced drying, a heat transfer heating method such as hot air drying, a far infrared heating method, or the like can be employed. From the viewpoint of the drying (water removal) rate, the use of far infrared rays is most preferable. However, the dryer used in the drying step in the present invention is not limited to a far-infrared dryer, and a hot-air dryer may be used. And a dryer using both far-infrared heating and heat transfer heating can be used. Specific conditions for drying in this case are, for example, using far infrared rays and heating at a heater temperature of 12.
0-180 ° C, ambient temperature 40-80 ° C, drying time 20
Conditions of ~ 120 minutes can be employed.

Next, the obtained dry molded body is processed into a predetermined shape. For example, it is cut into predetermined lengths by a punching press or sharing, and then directly processed into a predetermined shape according to the application. The cut product may be wound around the outer peripheral surface of a disk-shaped mold, or may be punched into a predetermined shape in a state in which a plurality of laminated products are laminated. The shape of the punching can be appropriately selected according to the use, such as a disk shape, a donut shape, a strip shape, and a rectangular shape. For example, in order to finish to a JIS 6A2 type grindstone, a predetermined donut shape is punched. In the case of using a 1A1 type grindstone, it is punched in a strip shape, and is further wound around the outer peripheral surface of the base metal.

The firing step is preferably a two-step process. The first step is called degreasing, and is a step of volatilizing organic substances (such as a binder), and the second step is a step of sintering metal powder. These degreasing and sintering steps can be continuous. In addition, in such a degreasing / sintering step, in order to prevent deformation (warpage) of the dried molded body or to further facilitate pressurization, for example, it is made of a thermally stable material such as carbon graphite or ceramics. It is preferable that the dried molded body be sandwiched between substrates made of a material that is unlikely to cause metal fusion and then fired. Also, when using a steel mold, the steel mold can be used without metal fusion by treating the steel mold with a ceramic coat or a graphite coat.

The degreasing step is performed, for example, in an air atmosphere, in an inert gas atmosphere such as a nitrogen gas atmosphere, or in a reducing gas atmosphere such as a hydrogen gas atmosphere, and further in a vacuum atmosphere.
It can be fired at a temperature of about 550 ° C. for a time of 30 to 120 minutes. In addition, depending on the type of metal to be manufactured, the sintering process may be performed under an ammonia decomposition gas atmosphere, a reducing atmosphere such as hydrogen gas, a vacuum, an inert gas atmosphere such as nitrogen gas, or an air atmosphere. So, for example, 600
It can be fired at a temperature of about 800 ° C. for 10 to 60 minutes. This sintering step is carried out under a pressurized condition, for example, 100 to
It can be performed at 1000 kg / cm ² . In addition, in the case of maintaining the porous structure of the obtained superabrasive grain during pressure sintering, for example, a hot isostatic press (HI
The P) method is preferred.

The porosity of the obtained sintered body is not particularly limited, and can be appropriately selected depending on the use of the grindstone. For example, if the superabrasive grindstone has a porous structure, it is possible to reduce the grinding resistance between the obtained blade and the object to be ground. Is good. In this case, the porosity is preferably 30% or less, specifically, about 10 to 25%.
For applications such as cutters and stone blades, the porosity is preferably as low as possible, specifically, it is preferably lower than 2%.

In order to obtain such a porosity, the amount of the water-soluble resin binder (binder) in the slurry is adjusted,
By adding a foaming agent, it can be arbitrarily adjusted by conditions such as pressure and temperature during sintering, and even when a foaming agent is added to the slurry, for example, by pressing during sintering, It is also possible to have a structure with a lower porosity or a denser structure.

The super-abrasive-containing metal sintered body thus obtained can be used for various types of grinding and polishing such as plunge cut grinding and contouring grinding, and for cutting and grooving. It can also be used for processing. Depending on such applications, for example, after finishing processing etc. to precise dimensions as necessary, using an adhesive such as epoxy resin on the base, or joining by brazing etc., it is made into a product .

The present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the present invention. For example, when the dried molded body is brittle, it is lost during firing of the foamed dried molded body and facilitates handling of the dried molded body, and the resin film does not affect the properties of the sintered body, for example, on a urethane coating film. The grindstone slurry can be formed into a plate shape using a doctor blade or the like. It is preferable that such a resin film does not shrink during the foaming and drying steps of the grindstone raw material slurry and completely disappears during firing.

[0031]

Embodiments of the present invention will be specifically described below. Example 1 As a metal powder, a copper powder having an average particle diameter of 5 μm mixed at a ratio of 85:15 (% by weight) and an average particle diameter of 1 were used.
0 μm tin powder was used. Diamond (6/12 μm abrasives, manufactured by Tomei Diamond Co., Ltd.) was mixed with the metal powder at the ratio shown in Table 1 to obtain a sintered mixed powder, and an aqueous organic binder solution was added to the sintered mixed powder and kneaded. In this case, the components in the organic binder aqueous solution were varied as shown in Table 2, and the appropriate amount of each component was evaluated. The compositions 1-1 to 1-5 were also examined as comparative examples. Using a binder of these compositions, φ100 × φ40 × 0.25
An attempt was made to produce a 1 mm thin blade of 1A8 mmt.

[0032]

[Table 1]

[0033]

[Table 2]

The kneaded materials kneaded according to the above composition table, each 55
g was stretched into a thin plate by the doctor blade method. Those that could be stretched into thin plates were dried to form green molded bodies. The approximate size of the green compact is 1
It was 20 × 200 × 0.7 mmt.

From this green compact, a disk-shaped green compact having an outer diameter of φ110 was punched by a hand press. The disc-shaped molded body was sandwiched between carbon discs of φ120, and a binder removal treatment was performed at 550 ° C. for 30 minutes in a nitrogen atmosphere.

Next, pressurizing (200 k
g / cm ² ), sintered at 650 ° C. for 30 minutes in a nitrogen atmosphere, punched out by a mechanical press, and φ100 × φ40 ×
A 0.25 mmt thin blade was produced. In the above process, determine whether the doctor blade is good for thin plate forming and the goodness of hand press punching.After sintering, place the blade on a stone plate and search for the place where the gap between the blade and the plate becomes the maximum. The gap in this portion was measured with a gap gauge to measure the warpage after sintering. Table 3 shows the results.

[0037]

[Table 3]

Comparative Example 1-2 contains a large amount of methylcellulose at the time of kneading, so that it has a high viscosity and a dumpling shape.
Sheet forming was difficult. Comparative Examples 1-1 and 1-4
In Nos. And 1-5, chipping occurred in the product part at the stage of punching by the hand press.

In Comparative Examples 1-3, the amount of the surfactant was not appropriate, the mixing of the raw material powder was insufficient, and the warpage was large. From the above results, the components of the aqueous organic binder solution are as follows: water-soluble resin binder: 0.5 to 20% by weight; surfactant: 0.5 to 3% by weight; plasticizer: 0.1 to 15% by weight; : It is recognized that the remaining range is appropriate. [Example 2] The composition of the aqueous organic binder solution of Example 1-3 was used, and the appropriate amount of the sintered mixed powder of abrasive grains and metal powder in the organic binder aqueous solution was evaluated. Diamond and metal powder mixed in a volume ratio of 25:75 used in Example 1 were kneaded with an organic binder aqueous solution at a ratio shown in Table 4, and production of a 1A8 thin blade was attempted in the same manner as in Example 1.

[0040]

[Table 4]

55 g of each of the above kneaded components was stretched into a thin plate by a doctor blade method. Those that could be stretched into thin plates were dried to form green molded bodies.
The approximate size of the green compact is 120 × 200 ×
0.7 mmt. From this green compact, a disk-shaped green compact having an outer diameter of φ110 was punched out with a hand press.

This disk-shaped molded body was made of carbon φ120.
And a binder removal treatment was performed in a nitrogen atmosphere at 550 ° C. for 30 minutes. Then, under this condition, pressurization (200 kg / cm ² ), sintering at 650 ° C. for 30 minutes in a nitrogen atmosphere, punching out with a mechanical press, and
A thin blade of 0 × φ40 × 0.25 mmt was manufactured.

The thin plate formability and the properties of the sintered body in the above steps were evaluated. Table 5 shows the results.

[0044]

[Table 5]

In Comparative Example 2-1, the density of the mixed powder after the removal of the binder was low, the powder became powdery, and a sintered body could not be obtained. In Comparative Example 2-2, it became a dumpling at the time of kneading, and a thin plate could not be formed. Based on the above results, the mixing amount of the organic binder aqueous solution and the sintering mixed powder is appropriately in the range of metal powder: 5 to 45 vol% organic binder aqueous solution: residual. [Example 3] According to the composition of Example 2-2, the volume ratio of diamond to metal powder was changed as shown in Table 6, and an appropriate amount of the abrasive was evaluated.

[0046]

[Table 6]

55 g of each of the kneaded products of the above-mentioned components was prepared, and these were formed into a thin plate by the doctor blade method. Those that could be stretched into thin plates were dried to form green molded bodies. The approximate size of the green compact was 120 × 200 × 0.7 mmt.

From this green compact, a disk-shaped green compact having an outer diameter of φ110 was punched out by a hand press. The disc-shaped molded body was sandwiched between carbon discs of φ120, and a binder removal treatment was performed at 550 ° C. for 30 minutes in a nitrogen atmosphere.

Next, pressurization (200 k
g / cm ² ), sintered at 650 ° C. for 30 minutes in a nitrogen atmosphere, punched out by a mechanical press, and φ100 × φ40 ×
A 0.25 mmt thin blade was produced. A cutting evaluation test of blue sheet glass was performed using a thin blade that could be manufactured. The test conditions are shown below. Machine used: Micro grinder made by Fujikoshi Blade rotation speed: 9420m / min Cutting depth: 2mm Cutting pitch: 1.25mm Feeding speed 100mm / min Coolant: Emulsion Work: Blue sheet glass (50 × 50 × 10mmt) Processing amount: 200 lines

[0050]

[Table 7]

In Comparative Example 3-1, the amount of diamond abrasive grains was small, and blue sheet glass could not be cut. Comparative Example 3-2
The amount of diamond abrasive grains was large, and cracks occurred at the punching press stage due to poor strength of the compact. From the above results, it is appropriate that the mixing ratio of the abrasive grains and the metal powder is: abrasive grains: 2.5 to 50% by volume metal powder: the balance. Example 4 Copper powder having an average particle size of 5 μm and an average particle size of 10
μm tin powder and iron powder having an average particle diameter of 10 μm are 70: 1.
A sintered mixed powder was prepared in which the metal powder mixed at a ratio of 4: 16% by weight was 75% by volume, and the diamond abrasive grains of MBG-II # 325/400 made by GE were 25% by volume. The sintered mixed powder was kneaded at a ratio of 30% by volume and an aqueous solution of an organic binder produced by the following composition at a ratio of 70% by volume using a kneader.

Organic binder aqueous solution component-Methyl cellulose 3% by weight-Alkyl benzene sulfonate 0.5% by weight-Water Remainder The kneaded product obtained as described above was stretched into a thin plate by a doctor blade method. The size of the obtained plate was approximately 120 × 200 × 3.0 mmt.

The plate was dried to obtain a green molded body. The green molded body had an outer diameter of 100 mm and an inner diameter of 94 m.
m was cut out with a hand press. The green compact can be stretched again into a thin plate by returning the green compact with hot water in the above ratio.

FIG. 1A shows the green compact.
550 is charged in a graphite mold as shown in FIG.
The binder was removed in a nitrogen atmosphere at 30 ° C. for 30 minutes. Next, pressurization (200 kg / c
m ² ) and sintered at 650 ° C. for 30 minutes in a nitrogen atmosphere to produce a grindstone layer 311 of φ100 × φ94 × 2.0 t.

Finally, this grindstone layer was bonded to a base metal shown in FIGS. 2A and 2B with an epoxy adhesive to produce a 6A2 type grindstone. [Comparative Example 4] Copper powder having an average particle size of 5 µm and an average particle size of 10
μm tin powder and iron powder having an average particle diameter of 10 μm are 70: 1.
A mixed powder comprising 75 vol% of metal powder mixed at a ratio of 4:16 and 25 vol% of diamond abrasive grains of MBG-II # 325/400 particle size manufactured by GE was prepared. These were mixed in a shaker type mixer for 30 minutes.

Next, 15.4 g of this mixture was charged into a mold and press-molded at a pressure of 5 t / cm ² to produce a press-formed body of the abrasive layer. Fig. 1
(A), loaded in a graphite mold as shown in (B),
Pressurized (200 kg / cm ² ), 650 ° C for 30 minutes,
Sintering was performed in a nitrogen atmosphere to produce a grindstone layer of φ100 × φ94 × 2.0 t.

Finally, this grindstone layer is applied to each of FIGS. 2 (A) and 2 (B).
Was bonded to the base metal shown in (1) with an epoxy-based adhesive to produce a 6A2 type grinding wheel. Grinding Test A grinding test of the grinding wheels obtained in Example 4 and Comparative Example 4 was performed under the following conditions. Then, the dimensions of the grindstone were measured to measure the wear amount of the grindstone. In addition, plunge grinding of carbon was performed to compare the state of wear. FIG. 3A shows a state before grinding of the grindstone of Example 4, and FIG.
3 (c) shows a state before grinding of the grindstone of Comparative Example 4, and FIG. 3 (d) shows a state after grinding of the grindstone of Comparative Example 4.

Grinding stone: φ100D, φ25H, 3W, 2X Testing machine: Makino C40 tool grinding machine Peripheral speed: 1000 m / min Table feed: 5 m / min Cutting amount: 500 cc Cutting depth: 0.5 mm / stroke Cutting fluid: Soluble Workpiece: Blue plate glass, 100L × 10W × 10t As a result, the wear amount of the grindstone is 0.24 cc for the grindstone of the present invention, whereas the comparative grindstone is 0.55 cc, and the wear amount of the grindstone of the present invention is very small. Was. Also, the change in the shape of the grindstone was smaller with the grindstone of the present invention. Example 5 Copper powder having an average particle size of 5 μm and an average particle size of 10
26 μm of tin powder and cobalt powder having an average particle size of 5 μm:
87.5% by volume of metal powder mixed in a ratio of 8: 66% by weight, and 1/20/30 μm DA abrasive made by De Beers.
A sintered mixed powder consisting of 2.5% by volume was prepared. 55 g of this mixed powder was kneaded using a kneader at a ratio of 30% by volume and an aqueous solution of an organic binder prepared by the following composition at a ratio of 70% by volume.

Organic binder aqueous solution component-Methyl cellulose 3% by weight-Alkyl benzene sulfonate 0.5% by weight-Polyethylene glycol 0.5% by weight-Water Remainder The kneaded material obtained as described above is formed into a thin plate by a doctor blade method. Stretched. The size of the obtained plate was approximately 120 × 200 × 0.6 mmt.

The plate was dried to obtain a green compact, and the green compact was cut into a strip-shaped compact having a width of 9.0 mm with a sheet cutter. Then, the green compact is wound around a copper base steel plate having a diameter of 203 x 50.8 x 9 tons, filled in a mold as shown in Fig. 5, and removed at 400 ° C for 30 minutes in a hydrogen atmosphere. Binder treatment was performed.

Next, pressurizing (200 k
g / cm ² ), sintered at 900 ° C. for 30 minutes in a nitrogen atmosphere, and cut the base metal protruding due to shrinkage of the grindstone portion to φ205 × as shown in FIGS. 4A and 4B. φ5
A 1A1 type grindstone of 0.8 × 5t × 1.0X was manufactured. [Comparative Example 5] Copper powder having an average particle size of 5 µm and an average particle size of 10
26 μm of tin powder and cobalt powder having an average particle size of 5 μm:
87.5% by volume of metal powder mixed in a ratio of 8: 66% by weight, and 1/20/30 μm DA abrasive made by De Beers.
The mixed powder consisting of 2.5% by volume was mixed for 30 minutes using a shaker type mixer.

[0062] and 5g weighed from this mixed powder, a steel base metal was copper plating treatment of the inner frame to φ203 × φ50.8 × 5t which was loaded into a mold set, and molded at a pressure of 3t / cm ² , To produce a green compact. This green compact was loaded into the mold shown in FIGS. 5A and 5B, pressurized (200 kg / cm ² ), and sintered at 900 ° C. for 30 minutes in a nitrogen atmosphere. A) and JIS 1A1 type grinding wheels as shown in (B) were manufactured. Grinding Test A grinding test was performed on the grinding wheel according to Example 5 and the grinding wheel according to Comparative Example 5 under the following conditions. Evaluation is 2
The grinding resistance and the amount of grinding wheel wear for each 5 cc grinding were compared. Table 8 shows the results.

Whetstone: φ205, 5t, 1.0x Testing machine: Okamoto surface grinder Circumferential speed: 2000 m / min Feeding speed: 1.8 m / min Cutting amount: 100 cc Cutting depth: 0.2 mm Cutting fluid: Soluble Workpiece: Alumina Ceramics

[0064]

[Table 8]

From the results shown in Table 8, it is recognized that the grindstone of the present invention has less grinding resistance and less wear as compared with the conventional grindstone. [Example 6] Copper powder having an average particle size of 2 µm and an average particle size of 5 µm
m tin powder, cobalt having an average particle size of 2 μm is 55: 1
75% by volume of metal powder mixed in a ratio of 5: 30% by weight,
25 CBN Type I abrasive grains of # 140/170 manufactured by GE
A mixed powder consisting of volume% was prepared. The mixed powder was kneaded with 40 vol% and 85 g of an organic binder aqueous solution produced by the following composition at a ratio of 60 vol% using a kneader.

Organic binder component ・ Methylcellulose 3% by weight ・ Alkylbenzenesulfonate 0.5% by weight ・ Pentane (blowing agent) 1.0% by weight ・ Water remainder The kneaded material obtained as described above was subjected to a doctor blade method. The sheet was stretched into a thin plate, and a foamed plate was obtained through the above-described foaming step. The size of the obtained plate is approximately 120
× 200 × 2.5 mmt.

This plate was dried to obtain a green compact, and a green compact having a width of 5.0 mm × 60 mm was punched from the green compact by a hand press. The green compact was loaded into a graphite mold as shown in FIGS. 7A and 7B, and subjected to a binder removal treatment at 550 ° C. for 30 minutes in a nitrogen atmosphere.

Next, at 750 ° C.,
Sintered in a nitrogen atmosphere for 0 minutes, 60L × 5W × 2.5
A chip-shaped grindstone of t × 2.5X was manufactured. By volume, the porosity was 25%. [Comparative Example 6] Copper powder having an average particle size of 2 µm, and an average particle size of 5 µm
m of tin powder, cobalt powder having an average particle size of 2 μm is 55: 1.
75% by volume of metal powder mixed in a ratio of 5: 30% by weight,
25 CBN Type I abrasive grains of # 140/170 manufactured by GE
The mixed powder consisting of 3% by volume is mixed with a shaker type mixer.
Mix for 0 minutes.

5 g of this mixed powder was weighed, loaded into a mold, molded at a pressure of 1 t / cm ² , and then 5.0 mm wide ×
A 60 mm rectangular green compact was produced. This green compact was loaded into a graphite mold shown in FIGS. 7A and 7B and sintered at 750 ° C. for 30 minutes in a nitrogen atmosphere to obtain a 60 L × 5 W × 2.5 t × 2.5 × square. A shaped whetstone was manufactured. Grinding Test A grinding test was performed on the grinding wheel according to Example 6 and the grinding wheel according to Comparative Example 6 under the following conditions. Evaluation,
The processing was performed with the processing time corresponding to the processing number. The change in the machining time when the machining allowance of the inner circumference was set to 200 microns in diameter, and this was taken as one machining number to 100 machining numbers was examined. Table 9 shows the results. Whetstone: 60L × 5W × 2.5 × 2.5tX ・ ・ ・
4 pieces / set Testing machine: Fuji Honing Co., Ltd. Circumferential speed: 80 m / min Reciprocating speed: 15 m / min Horn pressure: 20 kg / cm ² Allowance: 200 microns (diameter) Grinding fluid: Yushiro Chemical, SF45F Workpiece: FC250, φ100 × φ50 × 100L

[0070]

[Table 9]

As shown in Table 9, the grindstone of the present invention is excellent in chip discharge property and lubricating property is promoted by supplying a grinding oil to the grinding portion. Was about 1/3, which was excellent.

[0072]

According to the method for manufacturing a superabrasive metal bonded wheel of the present invention, a superabrasive wheel having less density unevenness, excellent uniformity of abrasive grain distribution, and excellent grinding power can be produced at a low cost. It can be provided at low cost.

[Brief description of the drawings]

FIG. 1 shows a graphite mold used in Example 1, (A) is a plan view, and (B) is a sectional view.

FIG. 2 shows a JIS 6A2 type grinding wheel, (A)
Is a plan view, and (B) is a sectional view.

3A and 3B are diagrams showing the results of a cutting test performed in an example of the present invention, in which (a) shows a state before cutting of the example grinding wheel, (b) shows a state after cutting of the example grinding stone, c) shows the state before cutting of the comparative example whetstone, and (d) shows the state after cutting of the comparative example whetstone.

4A and 4B show a state in which a green molded body is wound around a base metal in Example 5, (A) is a plan view, and (B) is a sectional view.

5A and 5B show a state in which a base around which the green molded body of FIG. 4 is wound is loaded in a mold, wherein FIG. 5A is a plan view and FIG.
Is a sectional view.

FIG. 6 shows a JIS 1A1 type grinding wheel, (A)
Is a plan view, and (B) is a sectional view.

7A and 7B show the graphite type used in Example 6, wherein FIG. 7A is a plan view and FIG. 7B is a cross-sectional view.

8A and 8B show a conventional cold press mold for pressing powder containing abrasive grains, wherein FIG. 8A is a vertical sectional view and FIG. 8B is a horizontal sectional view.

FIG. 9 is a plan view showing a grindstone sintered body formed in a ring shape.

FIG. 10 shows a superabrasive grindstone as a product.
(A) is a plan view and (B) is a sectional view.

FIG. 11 is a sectional view of a main part showing a doctor blade having two blades.

[Explanation of symbols]

201 ... outer frame mold 202 ... inner frame mold 203 ... upper punch 204 ... lower punch 210 ... mixed powder 211 ... grindstone sintered body 212 ... base metal 213 ..Super-abrasive grindstone 1A: plate-shaped molded body B: air bubble 2: bottom 60A: first blade 60B: second blade D: first blade 60A and second gap S · · · slurry of the cutting edge of the cutting edge of the gap G ₂ · · · second blade 60B of the gap G ₁ · · · first blade 60A of the blade 60B

Claims (4)

[Claims] 1. A slurry containing superabrasive grains and metal powder is prepared, the slurry is formed into a plate shape, and the obtained plate-like molded body is processed into a predetermined shape, and then fired. Manufacturing method of super abrasive metal bond whetstone. 2. The method according to claim 1, wherein the slurry is formed into a plate by a doctor blade. 3. The slurry comprises 5 to 45% by volume of a sintered mixed powder containing 2.5 to 50% by volume of superabrasive grains, 97.5 to 50% by volume of a metal powder, and 95% by volume of an organic binder aqueous solution.
The aqueous solution of the organic binder contains 0.5 to 55% by volume of the water-soluble resin binder.
The method for producing a superabrasive metal bond wheel according to claim 1 or 2, comprising 20% by weight and 0.05 to 3% by weight of a surfactant. 4. The method for producing a superabrasive metal-bonded grinding wheel according to claim 3, wherein the aqueous organic binder solution further contains 0.1 to 15% by weight of a plasticizer.