JPH10277950A - Manufacture of ultra-abrasive grain ceramic bond grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultra-abrasive grain grinding wheel which is small in density irregularity, excellent in uniformity of the abrasive grain distribution, and excellent in cutting property by preparing the slurry containing the ultra- abrasive grain and the ceramic powder, and working a plate-shaped molded body which is obtained by molding the slurry in a plate to the prescribed shape, and burning it. SOLUTION: In preparing the slurry of a grinding wheel raw material, the slurry containing the ultra-abrasive grain, ceramic powder, water-soluble resin binder, surfactant, plasticizer, and/or foaming agent, water, etc., is prepared. The prepared slurry is formed in a plate shape. Then, a plate-shaped molding body is dried. The dried molding body is cut to the prescribed length, and directly machined to a prescribed shape according to the applications. A burning process is a two-staged process. A first stage is referred to as degreasing, in which the organic matters are evaporated and diffused. In a second stage, the ceramic powder is sintered. An ultra-abrasive grinding wheel which is small in density irregularity, excellent in uniformity of the abrasive grain distribution, and excellent in the grinding capacity, can be provided at a low cost.

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 ceramic bonded grindstone applicable to a wide range of grinding such as grinding of difficult-to-cut materials such as nickel alloys or cobalt alloys and steel materials.

[0002]

2. Description of the Related Art Ceramic sintering containing diamond or cBN as super-abrasive grains used for grinding workpieces such as difficult-to-cut materials such as nickel alloys or cobalt alloys, steel materials, and various molded products such as FRP. As a method for producing a superabrasive ceramic bonded grindstone composed of a body, there is a conventional powder molding method as follows. For example, as shown in FIGS. 6 (a) and 6 (b), an outer frame die 601 and an inner frame die 602 that fits inside thereof, and a lower punch slidably inserted into a gap between these die dies. 604 and upper punch 603
A mixed powder of ceramic powder and superabrasive grains 610 is put into a ring-shaped gap formed by the following steps and pressed to obtain a ring-shaped molded body, which is sintered to form a ring as shown in FIG. Is manufactured, and this grindstone sintered body 611 is
As shown in FIGS. 6 (a) and 6 (b), it is bonded to the outer periphery of a disk-shaped base metal 612 to form a superabrasive grindstone 613.

[0003]

However, in the conventional powder molding as described above, since the powder is mixed in a dry manner,
Mixing unevenness of superabrasive grains and ceramic powder occurs, and density unevenness occurs during powder molding when the mixed powder is filled. As a result, the grinding resistance is high, the amount of wear is large, and it has been difficult to produce a grindstone having good grinding properties. In addition, the die for the cold press was greatly consumed, leading to an increase in manufacturing cost. The present invention has been made in view of such a situation, has a low density unevenness, and has excellent uniformity of abrasive grain distribution, and provides a manufacturing method capable of providing a superabrasive ceramic bond whetstone having good grinding ability at low cost. Make it self-supplied.

[0004]

In order to achieve the above object, a slurry containing superabrasive grains and ceramic powder is prepared, and this slurry is formed into a plate shape. A method for producing a superabrasive ceramic bond grindstone characterized by firing after processing into a shape of (1).
As a method of forming the slurry into a plate shape, a doctor blade method is preferable. In the present invention, the slurry
However, the volume ratio of superabrasives to ceramic powder is (5: 9
5)-(50:50) and the mixture is 30-80
% By weight, the balance being an organic binder, the organic binder being 0.5 to 20% by weight of a water-soluble material binder, 0.5 to 5% by weight of a surfactant, and the balance being water. Preferably, if necessary, a plasticizer may be added in an amount of 0.1 to 1.
5% by weight and / or 0.05 to 10% by weight of blowing agent
It is desirable to contain.

[0005] In the method for producing a superabrasive ceramic bonded grindstone of the present invention, a superabrasive and a ceramic powder as a binder component are mixed together with a liquid medium or the like in a slurry form, and the slurry is formed into a plate shape. Process into a predetermined shape and sinter. By suspending and dispersing the superabrasives and ceramic powder in the liquid medium in this manner, the aggregation of the superabrasives and the like can be prevented and the density unevenness can be suppressed. Further, by sufficiently kneading the slurry, the density can be reduced. It is possible to suppress unevenness and thickness variation. In particular, by suppressing the unevenness of the superabrasive grain distribution, it is possible to suppress uneven wear, chipping, and the like of the obtained superabrasive grindstone, and to obtain uniform characteristics. As a result, the amount of wear is reduced. It is possible to manufacture a super-abrasive ceramic bond whetstone having a small amount and excellent grinding power. To form the slurry into a plate shape, a doctor
The blade method is suitable and is economically advantageous because it does not use a mold for cold press, which is frequently used in the powder molding process, and is frequently used. In order to effectively disperse the superabrasive grains and the ceramic powder by the wet method and maintain the shape after the slurry is formed, the volume ratio of the superabrasive grains to the ceramic powder is (5:95). ~ (5
0:50) and 30-80% by weight of this mixture, the balance consisting of an organic binder, wherein the organic binder is
It is preferable that the water-soluble resin binder is 0.5 to 20% by weight, the surfactant is 0.05 to 5% by weight, and the balance is water. 0.1 to 15% by weight and / or
Alternatively, the foaming agent is preferably contained in an amount of 0.05 to 10% by weight. Organic binders such as these water-soluble resin binders, surfactants, plasticizers, and foaming agents disappear by firing.

[0006]

Embodiments of the present invention will be described below. The superabrasive ceramic bond grindstone of the present invention can be manufactured by, for example, a grindstone slurry preparing step, a forming step, a drying step, a press cutting step, a shaping step, a degreasing step, a sintering step, a base mounting step, and the like. it can. First, the preparation of a slurry for a grinding wheel raw material is performed by, for example, using a slurry mixer or the like to mix a slurry containing superabrasive grains, ceramic powder, a water-soluble resin binder, a surfactant, a plasticizer and / or a foaming agent, water, and the like. Prepare.

As super abrasive grains, for example, diamond grains,
Although cBN particles are used, the present invention is not limited to these. The superabrasive grain size is also not particularly limited, and is appropriately selected depending on the intended use of the superabrasive grindstone to be obtained.
Thicknesses of about μm are often used.

[0008] Also, as a type of ceramic powder,
Especially limited if it can be sintered below the melting point of superabrasives
But not mainly Na_TwoO-CaO-SiO_TwoAnd Na_TwoO
-B_TwoO_TwoO_Three-SiO_TwoSuch a vitreous material is used. This
Other than these, for example, A1_TwoO_Three, A1_TwoO_Three-Si
O_Two, Al_TwoO_Three-SiO_Two-MgO, ZrO_Two-Y_TwoO_Three,
Al _TwoO_Three-TiO_Two, Al_TwoO_Three-CaO, SiO_Two, Al
_TwoO_Three-ZrO_Two-CaO, TiO_Two-ZrO_Two-CaO,
MgO-Cr_TwoO_Three-TiO_Two, SiC, Si_ThreeN_Four, Al
N, Sialon, BaTiO_Three, BaFeO_ThreeEtc. are used
It is. The average particle diameter of the ceramic powder is 0.05-0.05.
The range of 5 μm, particularly 0.5 to 3 μm is preferred. Average particle size
Is less than 0.05 μm, it is difficult to increase the porosity of the sintered body.
On the other hand, when the average particle size exceeds 5 μm,
Dispersibility of ceramic powder in the furnace is reduced, and
Is difficult to obtain. In addition, ceramic powder and super abrasive
The compounding amount is 50 to 95% by volume, particularly 70 to 85% by volume.
Range is desirable.

To make these superabrasive grains and ceramic powder into a slurry, an organic binder is used.
The following components are blended in the organic binder. The water-soluble resin binder has a function of maintaining the shape of the plate-like molded body when the slurry is dried. It also functions as a slurry viscosity modifier. 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 0.5 to 20% by weight, particularly 2 to 10% by weight.
A range of weight% is preferred. If the compounding amount is less than 0.5% by weight, the strength of the dried molded article is low, which may be suitable for handling. On the other hand, if the amount is more than 20% by weight, the viscosity becomes too high and molding becomes difficult. is there.

Surfactants have the effect of improving the dispersion stability of superabrasives and ceramic powder in a liquid medium, and the effect of adding a foaming agent to stabilize the foaming state and forming micelles of the foaming agent. . Examples of the surfactant include an anionic surfactant such as an alkylbenzene sulfonate, an α-olefin sulfonate, an alkyl sulfate, an alkyl ether sulfate, and an alkane sulfonate; a polyethylene glycol derivative; Examples thereof include nonionic surfactants such as alcohol derivatives. The compounding amount of the surfactant is preferably in the range of 0.05 to 5% by weight, particularly preferably 0.5 to 3% by weight. 0.05% by weight
If the blending amount is smaller, the dispersion stability of the superabrasive grains and the ceramic powder cannot be improved, and the formation of micelles becomes unstable, which may make it difficult to keep fine bubbles. If the amount is more than the weight%, no further effect may be seen.

The raw material slurry according to the present invention may contain a plasticizer in addition to the above components. The plasticizer is for imparting plasticity to the molded article, and can prevent cracks during deformation processing such as winding of the dried molded article. The plasticizer is ethylene glycol-
, Polyglycols such as polyethylene glycol and glycerin, fats and oils such as sardine oil, rapeseed oil and olive oil, ethers such as petroleum ether, diethyl phthalate, dibutyl phthalate, diethylhexyl phthalate and phthalate Dioctyl acid, sorbitan monooleate, sorbitan trioleate, sorbitan palmitate, sorbitan stearate
And esters and the like. The amount of the plasticizer is 0.1%. 1 to 15% by weight, especially 2 to 10% by weight
Is preferable. The blending amount is 0. If the amount is less than 1% by weight, the plasticizing effect 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 stone according to the intended use. In this manner, a foaming agent is added to the slurry, for example,
After being formed into a plate shape by the doctor blade method, the foaming agent is foamed to form bubbles in the slurry, so that the superabrasive grains and the ceramic powder form fine bubbles in the grindstone slurry. Therefore, it is possible to prevent the superabrasive grains and the ceramic powder from settling and causing density unevenness inside the compact. When this is dried, it solidifies while maintaining the shape of the bubbles together with the water-soluble resin binder. When this is fired, the binder disappears and the ceramic powders sinter together,
A superabrasive grindstone having a foamed three-dimensional network structure having a bubble shape is obtained. 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 bubbles, and may be selected from a compound which decomposes at a certain temperature to generate gas, a volatile organic solvent, and the like. As a volatile organic solvent, for example, carbon number 5
8 hydrocarbon-based organic solvents. Such organic solvents are liquid at room temperature, volatile, and slurry.
Inside, they form micelles under the action of a surfactant and vaporize at room temperature or under heating to form fine bubbles. Carbon number 5
Examples of the hydrocarbon organic solvents of No. 8 to No. 8 include pentane,
Neopentane, hexane, isohexane, isoheptane, benzene, octane, toluene and the like can be mentioned. The compounding amount of the foaming agent is preferably in the range of 0.05 to 10% by weight, particularly preferably 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. Instead of using a foaming agent, it is also possible to adjust the grinding wheel raw material slurry by a method of vigorously mixing a gas such as air.

The raw material slurry for a grinding wheel according to 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. Slurry
Has a viscosity of 5000 cps to 70000 cp at 20 ° C.
The range of s, especially the range of 20,000 to 40,000 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 adjusted is formed into a plate shape. 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 a doctor blade, as shown in FIG.
Two blades 90A and 90B can be used. The reason is that two blades 90 are used as shown in FIG.
When using A and 90B, large air bubbles B are removed from the gap between these blades, and large bubbles do not enter the plate-shaped molded product 1A pushed out from the gap of the second blade 90B. This is because the thickness of the compact can be made uniform irrespective of the level of the liquid surface of the grindstone slurry S. in this case,
The gap G1 of the blade edge of the first blade 90A is the second blade 90A.
It is preferable that the gap be larger than the gap G2 of the blade edge of the blade 90B. The first blade 90A and the second blade 9
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. The foaming conditions are
If dried at the same time as foaming, cracks are likely to be formed on the surface of the molded body. Therefore, during foaming, it is preferable to perform drying in a high-humidity atmosphere in order to prevent drying as much as possible. 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. Foaming temperature is 15-65 ° C, especially 28-40 ° C
Is preferable. If the foaming temperature is lower than 15 ° C., foaming may take, for example, 2 hours or more. If the foaming temperature exceeds 65 ° C., the molded body may foam excessively and the molded body may collapse.
The foaming time is usually in the range of 10 to 45 minutes.

Next, the molded body formed into a plate by the doctor blade method 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 for several hours or half a day. Also, forced drying can be performed using a dryer. For 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 utilizing both far-infrared heating and heat transfer heating can be used. Specific conditions for drying in this case are, for example, the use of far infrared rays,
0-180 ° C, ambient temperature 40-80 ° C, drying time 20
Conditions of up to 120 minutes can be employed.

Next, the obtained dried 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 shape of the punching can be appropriately selected according to the application such as a disk shape, a donut shape, a strip shape, a rectangular shape, and the like. For example, JIS
In order to finish to a 6A2 type grindstone, it is punched in a predetermined donut shape. In the case of using a JlSlA1 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 stage is called degreasing, and uses organic matter (binder-
Etc.), and the second step is a step of sintering the ceramic powder. These degreasing step and sintering step can be continuous. Further, in such a degreasing / sintering step, in order to prevent deformation (warping) of the dried molded body or to further facilitate pressurization, for example, a heat treatment of carbon graphite, ceramics or the like is performed. It is desirable that the dried molded body is sandwiched between substrates that are made of a material that is stable in nature and that does not easily cause fusion, and is fired. The degreasing step is performed, for example, at a temperature of about 400 to 550 ° C. for 30 to 120 minutes under an air atmosphere, an inert gas atmosphere such as a nitrogen gas, or a reducing gas atmosphere such as a hydrogen gas, and further under a vacuum atmosphere. You can do it. In addition, depending on the type of ceramics to be produced, 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. For example, baking can be performed at a temperature of about 600 to 800 ° C. for 10 to 60 minutes. This sintering step is carried out under a pressurized condition, for example, 100 to 1000 kg / c.
m ² . When the porous structure of the obtained superabrasive grindstone is maintained during pressure sintering, for example, a hot isostatic pressing (HIP) method is suitable.

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 grindstone and the object to be ground. Good, double the lubrication and cooling effect. 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%. To achieve such a porosity, the amount of the water-soluble resin binder (binder) in the slurry is adjusted, a foaming agent is added, and the pressure and temperature during sintering are arbitrarily adjusted. Even if a foaming agent is added to the slurry,
For example, by applying pressure during sintering, it is possible to obtain a structure having a lower porosity or a dense structure.

The ceramic sintered body containing superabrasives obtained in this way can be used for various grinding processes such as contouring grinding and cylindrical grinding. Depending on such applications, for example, after cutting to precise dimensions as necessary, using an adhesive such as epoxy resin on the base metal, or joining by brazing etc. to the product Is done.

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 raw material slurry, and that it completely disappears during firing.

[0023]

Embodiments of the present invention will be specifically described below. Example 1 Na ₂ O—CaO having an average particle size of 2.0 μm
The -SiO ₂ powder 75 vol%, GE Co. MBG-II # 1
Diamond abrasive grains having a particle size of 70/200 were mixed at a ratio of 25% by volume, and 100 g of the mixed powder and 60 g of an organic binder produced according to the following composition were kneaded using a kneader. Organic binder component ・ Ethyl cellulose 3% by weight ・ Alkylbenzene sulfonate 0.5% by weight ・ Water remainder The kneaded material obtained as described above was stretched into a thin plate by a doctor blade method. The size of the obtained plate was approximately 120 mm × 200 mm × 2.0 mmt. The plate was dried to form a green compact, and a donut-shaped green compact having an outer diameter of 100 mm and an inner diameter of 55 mm was punched out of the green compact by a hand press. The green compact can be stretched again into a thin plate by returning the green compact with warm water in the above ratio. The green compact was loaded into an alumina mold as shown in FIG. 1, and the binder was removed in a nitrogen atmosphere at 550 ° C. for 30 minutes.
Processing was performed. Then, pressurization (10
0 kg / cm ² ), sintered at 680 ° C. for 3 hours in a nitrogen atmosphere, and a φ100 mm × φ55 mm × 1.2 mmt 1A8 type super-abrasive ceramic bond whetstone 1 of the present invention.
(Hereinafter, simply referred to as a grinding wheel 1 of the present invention).

Comparative Example 1 Next, for comparison, a powder of Na ₂ O—CaO—SiO ₂ having an average particle size of 2.0 μm
By volume, 25% by volume of diamond abrasive grains having a particle size of MBG-II # 170/200 manufactured by GE were blended at a ratio of 25% by volume and mixed with a shaker type mixer for 30 minutes. Next, 23 g of this mixture was charged into a mold, and press-molded with a pressure of 3 t / cm ² to produce a press-formed body of an abrasive layer. This press-formed body was loaded into an alumina mold as shown in FIG. 1, pressed (100 kg / cm ² ), sintered at 680 ° C. for 3 hours in a nitrogen atmosphere, and φ100 mm × φ55 mm
A 1A8 type conventional grindstone 1 of × 1.2 mmt was manufactured.

(Cutting Test) A cutting test of the grindstone 1 of the present invention and the conventional grindstone 1 obtained as described above was performed under the following conditions. Then, the cutting resistance and the wear amount of the grindstone were compared. Table 1 shows the results of the cutting test. Whetstone: φ100mm × φ55mm × 1.2mmt Testing machine: Slicer made by TOSHIBA MACHINE Circumferential speed: 1500m / min Feeding speed: 10mm / min Cutting amount: 100 pieces (1001ines) Cut: 3mm Pitch sending: 5mm Cutting fluid: Soluble processing Product: Carbide, 50mm × 50mm × 5mmt

[0026]

[Table 1] From the results shown in Table 1, it is recognized that the grindstone 1 of the present invention has a cutting resistance of about half that of the conventional grindstone 1 and a wear amount of about 2/3, and is excellent in cutting performance.

Example 2 Na having an average particle size of 3.0 μm
60 volume% of ₂ O-CaO-SiO ₂ powder, DE BEER
SBN ABN600 and # 325/400 cBN abrasive grains were mixed at a ratio of 40% by volume, and 120 g of the mixed powder and 60 g of an organic binder produced according to the following composition were kneaded using a kneader. Organic binder component ・ Methylcellulose 5% by weight ・ Alkylbenzene sulfonate 0.5% by weight ・ Polyethylene glycol (plasticizer) 0.5% by weight ・ Water remainder The kneaded material obtained as above is doctored. -It was stretched into a thin plate by a blade method. The size of the obtained plate was approximately 120 mm × 200 mm × 1.5 mmt. The plate was dried to form a green compact, and the green compact was cut to a width of 8 mm with a sheet cutter. Then, this green compact is made of φ195 mm × φ50.8 mm × 5
The material was wound around a steel plate of mmt, loaded into an alumina mold as shown in FIG. 2, and subjected to binder removal treatment at 550 ° C. for 30 minutes in a nitrogen atmosphere. Then, under this condition, pressure is applied (100 kg / cm ² ), sintering is performed at 900 ° C. for 2 hours in a nitrogen atmosphere, and φ2 as shown in FIG.
A 05 mm x 50.8 mm x 5 mm t1A1 type superabrasive ceramic bonded grindstone 2 of the present invention (hereinafter, simply referred to as the present invention grindstone 2) was manufactured.

Comparative Example 2 Na having an average particle size of 3.0 μm
60 volume% of ₂ O-CaO-SiO ₂ powder, DE BEER
SBN ABN600, # 325/400 cBN abrasive grains were blended at a ratio of 40% by volume and mixed with a shaker type mixer for 30 minutes. Next, 100 g of this mixture was charged into a mold and molded under a pressure of 3 t / cm ² to produce a pressed body of the abrasive layer. This press-formed body was loaded into an alumina mold provided with a steel base of φ195 mm × φ50.8 mm × 5 mmt as shown in FIG.
00 kg / cm ² ), and sintered at 900 ° C. for 2 hours in a nitrogen atmosphere to obtain φ205 mm × φ50.
An 8 mm × 5 mm t1A1 type conventional grindstone 2 was manufactured.

(Grinding Test) A surface grinding test using the grinding wheel 2 of the present invention and the conventional grinding wheel 2 was performed under the following conditions. The evaluation was performed based on the grinding resistance and the surface roughness of the processed surface. Table 2 shows the test results. Whetstone: φ205 mm × φ50.8 mm × 5 mmt Testing machine: Okamoto Machine Tool surface grinding machine Peripheral speed: 1000 m / min Feed speed: 10 m / min Cutting amount: 100 cc Cutting depth: 20 μm Cutting fluid: Emulsion Workpiece: FC250, 100 mm × 50 mm × 20mmt

[0030]

[Table 2] From the results shown in Table 2, the grindstone 2 of the present invention had a uniform distribution of cutting edges, a small grinding resistance of about 2/3, and a good surface roughness of about 1/2 as compared with the conventional grinding stone 2. .

Example 3 Pb having an average particle size of 1.5 μm
65% by volume of OK ₂ O—SiO ₂ powder and 3/20 μm cBN abrasive grains of borazon micron powder type 8/20 μm manufactured by GE
The mixture was mixed at a ratio of 5% by volume, and 100 g of the mixed powder and 80 g of an organic binder produced according to the following composition were kneaded using a kneader. Organic binder component ・ Methylcellulose 3% by weight ・ Alkylbenzenesulfonate 0.5% by weight ・ Pentane (foaming agent) 1.0% by weight ・ Water remainder The kneaded material obtained as above is doctor-blended. The resultant was stretched into a thin plate by the C method and a foamed plate was obtained through the above-described foaming step. The size of the obtained plate is approximately 130m
mx 130 mm x 3.0 mmt. The plate was dried to form a green compact, and a disk-shaped green compact having an outer diameter of 120 mm and an inner diameter of 80 mm was punched out of the green compact by a hand press. Then, the green compact was loaded into an alumina mold as shown in FIG.
The binder was removed in a nitrogen atmosphere at 00 ° C. for 30 minutes. Next, in this state, sintering was performed at 600 ° C. for 1 hour in a nitrogen atmosphere, and φ120 mm × φ80 mm
A disc-shaped grinding wheel layer of × 2 mmt was manufactured. From volume, the porosity was 25% by volume. Finally, this grindstone layer was bonded to the base metal shown in FIG. 5 with an epoxy-based adhesive to produce a 6A2 type superabrasive ceramic bond grindstone 3 of the present invention (hereinafter simply referred to as the present invention grindstone 3). .

Comparative Example 3 Pb having an average particle size of 1.5 μm
65% by volume of OK ₂ O-SiO ₂ powder and 3/20 μm cBN abrasive grains of Borazon Micron powder type 8/20 μm manufactured by GE
They were blended at a ratio of 5% by volume and mixed for 30 minutes with a shaker type mixer. Next, 50 g of the mixed powder was charged into a mold and press-molded at a pressure of 0.5 t / cm ² to produce a press-formed body of a grindstone layer. Fig. 4
And sintering in a nitrogen atmosphere at 600 ° C. for 1 hour, φ120 mm × φ80 m
A disc-shaped grindstone layer of mx 2 mmt was produced. Finally, this grindstone layer was bonded to the base metal shown in FIG. 5 with an epoxy-based adhesive to produce a 6A2 type conventional grindstone 3 (hereinafter simply referred to as conventional grindstone 3).

(Grinding Test) A grinding test using the grinding wheel 3 of the present invention and the conventional grinding wheel 3 was performed under the following conditions. The workpiece was ground by 100 cc grinding, and the grinding resistance (spindle motor current value) and the ground surface properties were evaluated at this point. Table 3 shows the results. Whetstone: φ120 mm × φ80 mm × 2 mmt Testing machine: Makino tool grinder Peripheral speed: 500 m / min Grinding amount: 50 cc Cutting speed: 104 m / min Table speed: 1 m / min Cutting fluid: Soluble Workpiece: SKD-11, 50 mm × 20 mm × 50mmL

[0034]

[Table 3] From the results in Table 3, the grindstone 3 of the present invention is compared with the conventional grindstone 3,
It is recognized that the grinding resistance is small and no seizure occurs.

According to the method for manufacturing a superabrasive ceramic 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 is acceptable to provide it at low cost.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a mold frame for subjecting a green compact to pressure sintering after degreasing, wherein (A) is a vertical sectional view and (B) is a horizontal sectional view.

FIG. 2 is a view showing a mold frame in which a green compact is wound around a steel base, degreasing and pressure sintering, wherein (A) is a vertical sectional view and (B) is a horizontal sectional view. is there.

FIG. 3 shows an lAl type superabrasive grindstone as a product.

FIGS. 4A and 4B show a mold for sintering a green compact after degreasing, and FIG. 4A is a vertical sectional view and FIG. 4B is a horizontal sectional view.

FIG. 5 shows an example of a superabrasive grindstone as a product. (A) is a vertical sectional view, and (B) is a plan view.

6A and 6B show a conventional cold press die for pressing powder containing abrasive grains, wherein FIG. 6A is a vertical sectional view and FIG. 6B is a horizontal sectional view.

FIG. 7 is a plan view showing a grindstone sintered body formed into a ring shape.

FIG. 8 shows a superabrasive grindstone as a product, and (a)
Is a plan view, and (b) is a vertical sectional view.

FIG. 9 is a sectional view of a main part showing a two-blade doctor blade method.

Claims (4)

[Claims] 1. A slurry containing superabrasive grains and ceramic powder.
, The slurry is formed into a plate shape, and the obtained plate-shaped formed body is processed into a predetermined shape, and then fired, and then fired. 2. The method for producing a superabrasive ceramic bond whetstone according to claim 1, wherein said slurry is formed into a plate shape by a doctor blade method. 3. The slurry according to claim 1, wherein the volume ratio of the superabrasive grains to the ceramic powder is (5:95) to (50:50), the mixture is 30 to 80% by weight, and the remainder is an organic binder.
The organic binder comprises 0.5 to 20% by weight of a water-soluble resin binder, 0.5 to 5% by weight of a surfactant,
The method for manufacturing a superabrasive ceramic bond whetstone according to any one of claims 1 to 2, wherein the remaining part is made of water. 4. The organic binder according to claim 1, further comprising a plasticizer.
4. The method for producing a superabrasive ceramic bond whetstone according to claim 3, comprising 1 to 15% by weight and / or 0.05 to 10% by weight of a foaming agent.