JPH02180560A - Super abrasive grain grindstone and manufacture thereof - Google Patents

Abstract

PURPOSE:To enable grinding of high performance for the grinding of a material difficult to grind by strongly holding super abrasive grains by a bonding material of excellent wear resistance and having a pore as well. CONSTITUTION:A grindstone contains super abrasive grains at >=5vol.% and <=60vol.%. Moreover the bonding phase of the residual part is composed of 50-90vol.% of a carbide, nitride, oxide, silicide or at least one kind of those solid solutions and 10-50vol.% pore. The above super abrasive grain is composed of at least one kind of a diamond, cubic boron nitride and wurtzite boron nitride. As for the manufacture, the above abrasive grain layer component powder 1 is pressurized, DC and AC are simultaneously flowed by passing push rods 13a, 13b and the reaction of each component is started. Both DC and AC are cut off immediately after the reaction start and the temp. rise more than that is constrained. After completion of the reaction, a grindstone material strongly bonding the abrasive grain layer to the grindstone base metal is obtd.

Description

[Detailed description of the invention] [Industrial application gff] The present application relates to a grinding wheel using super abrasive grains such as diamond and a method for manufacturing the same, and specifically relates to a grinding wheel using super abrasive grains such as diamond, and more specifically, a grinding wheel using super abrasive grains such as diamond, and a method for manufacturing the same. The present invention relates to a new superabrasive grindstone suitable for high-precision, high-efficiency machining of materials, and a method for manufacturing the grindstone using simple equipment and means.

[Prior Art] Conventionally, this type of device is as follows.

Diamond, cubic boron nitride (hereinafter abbreviated as CBN)
and wurtzite boron nitride (hereinafter abbreviated as WON) are called superabrasive grains, and these superabrasive grains have far superior hardness and toughness than conventional alumina and silicon carbide abrasive grains, and have high wear resistance.

Therefore, a grindstone using these superabrasive grains exhibits excellent grinding performance that greatly exceeds the grinding performance of a grindstone using conventional abrasive grains.

In particular, the current situation is that high-efficiency machining of high-hardness, high-strength materials that have been developed one after another in recent years has no choice but to rely on these superabrasive grindstones.

Grinding wheels using superabrasive grains can be broadly classified into metal pound grinding wheels, resin pound grinding wheels, and vitrified pound grinding wheels, depending on the type of bonding material. Cu-5n alloy is the mainstream as a binding material for metal pound grinding wheels, and Z
An alloy containing n, Ml, or other metals is used.

Metal pound whetstones have a high abrasive grain storage capacity and the pound material has excellent abrasion resistance, but because of this excellent abrasion resistance, it wears out appropriately during the grinding process required for a whetstone, and the abrasive grains are gradually removed. The cutting edge lacks the self-forming ability of exposing and exposing.
It has the disadvantage of poor cutting quality.

Furthermore, as the binding material for the resin pound grindstone, phenol resin is mainly used, and in addition to this, resins such as polyimide and epoxy are also used.

Resin ponds are softer than other metals or bi-tripoid pond materials, so they have the characteristic of being able to reduce the impact that is applied to the grindstone during grinding operations.

However, on the other hand, there are disadvantages in that the holding power of the abrasive grains is weak, the abrasion of the pound material is large, and the abrasion of the grindstone is significant.

On the other hand, artificial glass frit is mainly used as the binding material for vitrified bond grinding wheels.
Natural ceramic raw materials, such as feldspar and clay, may also be used.

Vitrified bond grinding wheels made of these materials have wear resistance that is intermediate to metal pound or resin pound wheels, and take advantage of the high rigidity of the pound material itself, and are mainly used in the field of precision grinding. used.

In recent years, attempts have been made to process structural ceramic materials such as 51sN4 and SlC, which have high hardness and high strength, using this highly rigid vitrified pound grinding wheel, but satisfactory results have not yet been obtained.

This is thought to be due to the weak abrasive retention power of conventional vitrified bond grindstones when grinding these new materials, which are called difficult-to-machine materials, as well as the low wear resistance of the bonding material. ing.

Various improvements have been made with the aim of strengthening the abrasive retention force and improving the wear resistance of the bonding material.

One method is to add alumina or silicon carbide as aggregate to the glass bonding material as auxiliary abrasive grains in order to increase the wear resistance of the bonding material.The other method is to add glass frit material to each abrasive grain. The aim is to increase the abrasive retention force by selecting the optimal one for each case and increasing the physicochemical wettability of the abrasive grains and the binder.

Furthermore, there is also a method that combines these two improvements.

[Problems to be Solved by the Invention] The conventional techniques described above have the following problems.

When processing difficult-to-cut materials such as structural ceramics, which have recently been developed, superabrasives that meet market demands are needed from the standpoint of grinding efficiency and accuracy, as well as residual stress issues during grinding. Grain grindstones are not yet commercially available.

As mentioned above, metal pound grinding wheels are certainly superior in terms of abrasive retention and wear resistance of the bonding material, but when processing difficult-to-cut materials such as structural ceramics, it is especially important that there is no impact load during grinding. Grinding under high rigidity is required, and metal pound grinding wheels with inferior rigidity are not suitable for such purposes.

Vitrified bond grinding wheels generally consist of abrasive grains, a bonding material, and pores, but when processing difficult-to-cut materials, wear of the bonding material becomes more pronounced than wear of the abrasive grains. whetstones are commercially available.

By eliminating pores in the grinding wheel, the area for holding the abrasive grains is increased, thereby increasing the abrasive grain retention power.By eliminating pores, the strength of the bonding material itself is increased and its wear resistance is improved. The purpose is to

However, this type of whetstone does not have the ability to make new abrasive cutting edges appear during grinding, and it is necessary to perform shaping by truing and dressing to make cutting edges appear at the beginning of grinding work and often during grinding work. It takes time and effort.

Moreover, this is a major obstacle when applied to automatic grinding equipment, and is also difficult to apply to precision grinding.

Furthermore, the pores of a grindstone are closely related to the grinding performance itself. During grinding, the pores act as so-called chip pockets to remove chips, and when grinding a rigid material that is prone to clogging or the generation of grinding heat is a problem, the pores act as pockets that efficiently transport cooling water. It also acts as

As a result, the pores in the grindstone enable sharp grinding with less clogging and generation of grinding heat.

Therefore, a grindstone that does not contain pores that functions in this way is
In addition to the above-mentioned drawbacks, especially for grinding high-strength, high-toughness materials,
In this case, clogging is likely to occur, which increases grinding resistance and generates significant grinding heat.

Furthermore, there was a problem in that this heat could not be efficiently removed by cooling water.

The generation of grinding heat causes microcracks to occur on the surface of the rigid material, reducing the strength and reliability of the material.

The present application was made in view of the problems of the prior art, and its purpose is to provide a system that can do the following.

The purpose of the present invention is to improve the above-mentioned drawbacks and problems of conventional vitrified bond superabrasive grinding wheels in the grinding of hard, high-strength, difficult-to-cut materials. The excellent bonding material strongly holds the superabrasive grains and also has pores, making it suitable for grinding difficult-to-cut materials.
An object of the present invention is to provide a new superabrasive grindstone that enables high-performance grinding and a method for manufacturing the grindstone using simple equipment and means.

[a[! Means for Solving] In order to achieve the above object, the present invention is as follows.

The present inventor has developed a method for processing high-hardness, high-strength rigid materials.
We have been conducting extensive research with the aim of developing a pound material for grinding wheels with excellent wear resistance and abrasive grain retention.

As a result, an abrasive layer forming powder containing a component that participates in a self-heating reaction that has the property of reducing its volume due to reaction is used as part or all of the starting raw material for the binder component, and the self-heating reaction is ignited. By starting the process and sintering the powder that makes up the abrasive grain layer, the abrasive grains are firmly held by the reaction product.
In addition, it was discovered that a grindstone having uniform pores can be obtained, and that the bonding material thereof has excellent wear resistance, and based on this knowledge, the present invention was completed.

That is, the present invention includes superabrasive powder containing (a) metal carbide,
(b) a component consisting of at least one element of nitride, boride, oxide, silicide, or a solid solution thereof; When blending the components that produce at least one kind, blending and molding the mixed powder so that the volume % of component (b) is 20% or more of the remaining starting material composition excluding the superabrasive grains, It is characterized by starting and advancing a self-heating reaction by heating a part or the whole thereof, and sintering the abrasive grain PJ 11 powder containing superabrasive grains, in which the superabrasive grains are contained at 5% by volume or more and 50% by volume. %, and the remaining binder phase is composed of at least one of carbides, nitrides, oxides, silicides, or solid solutions thereof, and pores.

In the synthesis of certain ceramics, especially high melting point compounds,
The heat of compound formation from its constituent elements reaches several 10 to several 100 kJ per mole.

This large heat of formation propagates into the raw material powder one after another, exciting and starting reactions one after another, and sustaining the reactions.

For example, one knife! When synthesizing TI and C powders, TI and C powders in a stoichiometric ratio of TI and C are mixed and molded,
When ignition and reaction are started from one end using a heating wire made of tungsten or the like, the reaction spreads throughout the molded body, and TIC can be synthesized without external heating.

This method of synthesizing ceramics does not require a special furnace for synthesis, is economical, and has recently attracted attention.

This reaction is self-propagating from a thousand properties.
Ing Hlgh-Temperature Synt
It is called hesig (abbreviated as 5H5) and is a Japanese B1? There is no unified name for this reaction yet, and it is called a self-heating reaction or self-combustion reaction.

The former name is adopted here.

Table 1 shows some examples of high melting point ceramics that can be synthesized by such self-heating reactions.

Example of high-melting point ceramics The characteristics of self-heating reactions are that the heat of reaction is extremely large, and that the volume decreases due to the reaction is large, although the proportion depends on the material.
In many cases, it reaches 30%.

In the present invention, a component that participates in a self-heating reaction that has the property of reducing its volume due to reaction is used as a part or the whole of the starting raw material for the binder component, but for this purpose, the following raw materials and components are used. You can use that reaction.

Nitrogen atmosphere 1) ^l → ^1N 2) Tl◆28 = TIB! 3) 2Ta * C+ 28 = TaBa +
TaC4) 3Cr20m+8^l◆4C→2Crs
C*◆3^l, 0゜5) Mo5s ◆2^1 Rei2
Sl -h Mo5I2+^1,0° The temperature increase due to heat accompanying the self-heating reaction can be calculated on the assumption that all of the heat of formation is used to raise the temperature of the product.

When the heat of adiabatic synthesis reaction calculated in this way reaches the melting point of the product, a liquid phase appears during the reaction, atoms diffuse easily, and the self-heating reaction progresses easily.

The synthesis of TlB2 from TI and 8 is such an example.

On the other hand, in the reaction of synthesizing -SIC from SI and C, the heat of formation is as small as 1 mol of aqkJ, and the resulting temperature increase does not reach the melting point of SIC, 2400°C.

For two reasons, this reaction stops halfway even if it ignites once.

When using this type of reaction, the reaction can be continued by preheating the compact to about 1000° C. and igniting it so that a portion of the liquid phase is generated during the reaction.

In the present invention, by utilizing the reaction in which a part of the liquid phase is generated during the reaction, it is possible to distribute the binder so as to sufficiently envelop the abrasive grains, and physically strengthen the holding power of the abrasive grains. It is considered that it was made.

In addition to diamond, the present invention also includes diamond as a superabrasive grain.
CBN%WON can be used, but in order to increase the retention of these abrasive grains by the binder, it is necessary to use metal powders that have a chemical affinity with carbon, nitrogen, and boron as the starting material for the binder. Items 4a and 5 of the periodic table, which are highly metallic and produce highly hard ceramics through reaction.
a. Powders of group Ba metals are suitable.

This is because these metals easily react with the low-pressure phase materials that are thought to thinly cover the grain surfaces of diamond and CBN%IBM, and the reaction product forms the superabrasive grain and the ceramic bonding material. This is thought to be because it plays a role of mediating the bond with.

The grinding wheel according to the present invention was able to exhibit much better abrasive retention power than when ceramic compound powder was simply used as a binder, but this result was due to the combination of the above-mentioned physical and chemical effects. it is conceivable that.

Furthermore, in order to strengthen the retention of the abrasive grains by the binder, as the abrasive grains, the abrasive grains from No. 4a of the periodic table can be used.

5a, abrasive grains whose surface is thinly coated with a Ba group metal can be used as the starting material. This metal on the surface can participate in the reaction in the same way as the additive metal powder, and is effective in making the bond between the abrasive grains and the binder even stronger.

The wear resistance of the bonding material mainly depends on its hardness, and the material for the bonding material must be selected in accordance with the strength and hardness of the material to be stiffened.

The bonding material for the whetstone does not just have to have excellent wear resistance as mentioned above; As the abrasive grains wear out during the grinding process, the bonding material itself gradually wears down, and new abrasive grain edges appear one after another, so that good cutting quality must be continuously checked.

Therefore, for example, in the case of relatively soft rigid materials, highly hard and wear-resistant materials such as TIC and Tl1h are rather unsuitable as bonding materials for grinding wheels; .

Materials with relatively low hardness such as oxides and silicides are more suitable.

On the other hand, for the processing of many high-hardness, high-strength structural ceramics that have recently been developed, carbides, nitrides, and
Borides or solid solutions thereof are suitable.

In the present invention, as a starting material for the constituent components of the grinding wheel binding material,
At least one of metal carbides, nitrides, borides, oxides, silicides, or solid solutions thereof can be used alone or in combination with components that produce a ceramic compound through a self-heating reaction.

In this latter case, the ceramic component such as metal carbide that is added has the following two roles.

One is that when the reaction heat associated with a self-heating reaction is extremely large, the addition of this component dilutes the reaction heat, thereby suppressing the temperature of the entire grindstone at a certain appropriate point.

The other is that when the porosity increases significantly due to the self-heating reaction, the addition of the above components relatively reduces the amount of components involved in the self-heating reaction and adjusts the porosity in the grinding wheel. .

For example, when Tl1h is selected as the binder for diamond abrasive grains and titanium powder and borax powder are used as the starting materials, the reaction heat associated with the reaction of Tl◆2B→71B is extremely large, and the reaction part at this time The temperature is 3000℃
It becomes close too.

At this time, the equilibrium temperature of the abrasive grain layer (layer consisting of superabrasive grains and binder) reaches as high as 1,500 t to 2,000° C., and conversion to a soft low-pressure phase occurs on the surface of the diamond abrasive grain.

Some of them can participate in the reaction with TI and become TiC, but
Most of the other particles are interposed as they are between the abrasive grains and the binder, which is undesirable because the abrasive retention force of the binder is significantly reduced.

Here, if a compound such as alumina or silicon carbide is added in addition to the (1+8) mixed powder as a raw material for the binder component, the heat of formation of τ1B is the same, but the abrasive layer The temperature is suppressed below the inverse variation #h temperature of diamond, and it is possible to obtain a superabrasive grindstone having a bonding material with excellent abrasive grain retention and wear resistance.

However, if the amount of components involved in the self-heating reaction in the starting material of the binder component is less than 20% by volume, the dispersion of the reaction heat becomes large and the exothermic reaction cannot be sustained, so ignition is possible. But it stops midway.

゛In such cases, the self-heating reaction can be sustained by heating the abrasive grain layer to a high temperature, but in this method, the reverse conversion to the low-pressure phase occurs on the superabrasive grain surface as described above, Undesirable.

As a result of experiments, the amount of the component involved in the self-heating reaction in the starting material of the binder component is required to be 20% by volume or more, preferably 40% by volume or more.

Here, the upper limit of this component is determined by the type of self-heating reaction used, and if the temperature rise accompanying the reaction is small, the upper limit of this component is 100% by volume, that is, the entire binder component is the component participating in the reaction. It can be composed of

The volumetric shrinkage associated with the self-heating reaction is often 15-30%, as mentioned above.

However, in reality, the starting material for the reaction is a powder compact, and in addition to the pores at that time, pores due to the vaporization of volatile components at the high temperature part during the reaction are also added, resulting in a state without pressurization. The porosity of this type of reaction product reaches 50 to 60%.

In cases such as clip-feed grinding with high depth of cut and low feed conditions, such high-porosity grinding wheels may be appropriate, but in other applications, the abrasive retention power and wear resistance of the bonding material may be affected. Therefore, it is necessary to adjust the porosity to 10 to 40%.

As a starting material for the grinding wheel binding material component, a ceramic compound that does not participate in the self-heating reaction has the effect of relatively reducing the amount of the exothermic reaction component and adjusting the porosity after the reaction. .

Diamond, CBN%IIIBN, as described above, can be used as the abrasive grains of the superabrasive grindstone according to the present invention, but from the viewpoint of chemical affinity with the material to be stiffened, it is difficult to grind high-hardness iron-based materials. A grindstone using CBN%WON abrasive grains is suitable for grinding, and a grindstone using diamond abrasive grains is suitable for grinding high hardness ceramic materials.

The content of abrasive grains in this case needs to be at least 5% by volume or more from the viewpoint of grinding performance, but if the amount exceeds 60%, the amount of abrasive grains becomes relatively too large, and the abrasive grains due to the binding material Holding force becomes weaker and grinding performance deteriorates.

The superabrasive grain content in the grindstone according to the present invention is 5% by volume or more,
Less than 60% by volume, preferably 10-40% by volume
is within the range of

Matrix-type grinding wheels, which are commercially available as an improved version of conventional grinding wheels, sacrifice the pores that play an important role in the grinding process, as described above, to increase the holding power of the abrasive grains, and to increase the retention of the binder. It was developed with the aim of increasing wear resistance.

In the method for manufacturing a superabrasive grindstone according to the present invention, a component that generates a ceramic compound and new pores through a self-heating reaction is used as part or all of the starting materials for the binder component, which is important in grinding processing. It has high abrasive retention without sacrificing the pores.

It has the characteristic that a bonding material with high wear resistance can be easily formed.

This allows the superabrasive grindstone to exhibit its inherent excellent grinding properties.

The superabrasive grindstone according to the present invention can be applied by applying pressure such as a hot press,
Although heating methods are useful in manufacturing, they are not always necessary.
It can be manufactured by the method described below.

A single component or a mixed powder that generates a ceramic compound through a self-heating reaction is added to the superabrasive powder, and if necessary, a ceramic compound is added to the abrasive layer constituent powder after molding or into a mold. At least a part or the whole of the molded body filled with the mixed powder is heated to initiate and advance the reaction.

The self-heating reaction can be ignited and started at room temperature or under heating conditions of 1200° C. or lower, for example, by bringing a heated tungsten wire close.

FIG. 1 shows an embodiment of a grindstone manufacturing apparatus using a heating wire that is used for manufacturing a grindstone according to the present invention.

The powder 1 forming the abrasive layer formed with the grinding wheel base 2 is placed in a container 6 in which the atmosphere can be adjusted as shown in FIG. Place a tungsten wire 4 for heating as shown in the figure.

Next, this tungsten wire 4 is heated by energizing it,
This initiates a self-heating reaction.

The reaction occurs throughout the powder constituting the cylindrical abrasive grain layer.
It is possible to obtain a grindstone material in which a sintered abrasive grain layer is firmly bonded around the sintered abrasive grain layer.

The ignition atmosphere for the reaction may be an oxidizing atmosphere in cases where the product of the exothermic reaction is an oxide and the component added to the starting material is an oxide ceramic, but in other cases. A vacuum atmosphere, nitrogen atmosphere or inert atmosphere is preferable.

As a method of igniting the self-heating reaction, there is also a method using a heating wire as described above, but it always contains metal powder as a part of its components, like the starting material of the grindstone according to the present invention. In such a case, it is also possible to use an ignition method that utilizes instantaneous heating through direct energization.

FIG. 2 shows a grindstone manufacturing apparatus using a discharge heating method.

In the figure, 11 is a mold, 12 is an insulating material cylinder, 13a is an upper push n%, 13b is a lower push rod, 14 is an insulating sheet, 15
is a pedestal, 1B is a pressure ram, and 1F is a mold support ring.

As shown in FIG. 2, the lower push rod 13b is set in a cylindrical mold 11 made of iron or the like with an insulating cylinder 12 of sintered alumina or the like inside, and then the lower push rod 13b is placed on top of the lower push rod 13b together with the grindstone base metal 2.
Load the abrasive layer constituent powder 1 and press the upper part 13m on top of it.
, and pressurize the upper push rod 13a with the pressurizing ram ta1 through the insulating sheet weight 4 made of thin Teflon or the like. Apply light pressure to about 300 lbs.

A thin insulating sheet 14 made of Teflon or the like is also placed between the metal pedestal 15 and the lower push rod 13b.

The upper and lower push rods 13a and 13b are made of graphite or metal, and are connected to a power source for discharge heating. Discharge heating is performed by the pressurizing ram 16, and the upper and lower push rods 13a, 1
With the powder 1 making up the abrasive layer layer lightly pressurized through 3b, a superimposed current of grammar and direct current is applied to the circuit of the upper push rod 13a - the powder 1 making up the abrasive grain layer - the grinding wheel base 2 - the lower push rod 13 b. This is carried out by flowing, thereby starting a reaction in the powder 1 constituting the abrasive grain layer, and sintering it.

For example, in the case of a molded body obtained by mixing diamond abrasive grains with an equimolar mixture of titanium and carbon at 70% by volume, a superimposed current of a direct current of SOO^ and a high frequency current SOO^ of 5 OGHz per CI2 is applied for several seconds. When flowing, the temperature of the molded body instantaneously reaches 1000° C. or more, and the reaction begins.

In this case, heating occurs mainly at the grain contacts between the metal powders and between the metal powder and the carbon powder, which initiates a chemical reaction, and if the current is stopped at this point, the entire abrasive grain layer will be heated. There is no need to heat the superabrasive more than necessary, and reverse conversion on the surface of the superabrasive grain, which has a negative effect, can be suppressed, which is advantageous.

Furthermore, this method allows for more uniform ignition, rather than ignition at one location on the molded body as is the case with the tungsten wire method, and is effective in increasing the uniformity of the resulting grindstone.

In addition, in the production of the grindstone according to the present invention, pressurization is not necessarily necessary as described above, but if it is desired to keep the porosity of the finished grindstone low, ignition may be performed with the forming mold filled with the starting material. However, the reaction can also be allowed to proceed while pressurizing.

Except for small-diameter grinding wheels for internal grinding, grinding wheels using general super-abrasive grains are expensive, so
It has a composite structure consisting of an abrasive grain layer with a thickness of 1 to 5 mm containing abrasive grains and an alloy part that does not contain abrasive grains.

Although the example described above is an example of a method for manufacturing a grinding wheel with such a composite structure, a comparatively small diameter superabrasive grinding wheel with an alloy-free structure can also be manufactured by a method similar to that described above.

As a method for manufacturing the grindstone according to the present invention, there is a method using impact compression.

This method is particularly suitable for manufacturing a grindstone with a large diameter and a thin abrasive grain layer, which is difficult to manufacture using a normal grindstone manufacturing method.

In the impact compression of powder, high temperatures are generated due to the adiabatic compression.

The degree of generation of this high temperature can be adjusted by the initial density of the powder, and the lower the initial density, the higher the temperature generated under constant pressure.

The initiation of a self-heating reaction by impact compression utilizes the heat accompanying such adiabatic compression of powder.

In this method, the starting material is once compressed to a high density and the pores are reduced to almost zero, but most of the exothermic reaction occurs not during compression but after the pressure is released, so the pores generated by this reaction are It can be left as is in the product abrasive layer.

FIG. 3 shows an embodiment of a cylindrical shock wave compression device that can be used in the grindstone manufacturing method according to the present invention.

Metal or wooden plugs 20a at the top and bottom.

In a cylindrical sample container 22 having a metal center rod 24 along its central axis as shown in FIG. 3, a thin cylinder formed inside the center rod 24 and the cylindrical sample container 22 The abrasive layer constituting powder 1 is uniformly filled into the space of .

Here, as the material for the cylindrical sample container 22, scrap metal, plastic, and paper can be used.

The outside of the cylindrical sample container 22 is filled with explosives 25.

By detonating the explosive 25 with the detonator 18 and propagating the explosion downward, a detonation shock wave is first transmitted to the cylindrical sample container 22, and then this shock wave detonates the powder 1 constituting the abrasive grain layer. f
I-hit compression.

This impact compression initiates a reaction in the powder constituting the abrasive grain layer, and at the same time sintering occurs, it is firmly joined to the middle rod 24.

Here, it is advantageous if the center rod 24 is made of iron or aluminum alloy so that after the abrasive grain layer is sintered, the center rod can be used as it is as a grindstone base metal.

On the other hand, if the diameter of the grinding wheel is relatively small,
4, that is, the powder constituting the abrasive grain layer is directly filled into the cylindrical sample container 22, and the explosive 25 is placed outside of it.
It is also possible to detonate the sample with the detonator 18 and impact-compress the sample to produce a grindstone material.

In addition, as a method of impact compression, as shown in FIG. 4, another drive tube 26 with a large diameter is placed outside the cylindrical sample container 22 of FIG. A space is created in between, and an explosive 25 is placed outside the drive tube 26. It is also possible to use a method of detonating the explosive 25 with the detonator 18 and causing it to collide with the cylindrical sample container 22 to generate a shock wave, which is then propagated to the sample to impact-compress the powder constituting the abrasive layer. can.

Also, depending on the shape of the target grinding wheel, especially when the width of the abrasive grain layer in the circumferential direction of the wheel is large but the thickness is thin, such as a cup wheel type, the cylindrical method described above may be used. In some cases, it may be easier to manufacture grindstones using the plane wave method.

FIG. 5 shows an embodiment of a planar If compression device that can be used for manufacturing a grindstone according to the present invention.

This device consists of an explosive lens 2 for producing plane 'aIi waves.
Explosive system including 8 and sample container 30m.

It consists of momentum traps 32a and 32b to facilitate the collection of 30b.

The powder constituting the abrasive grain layer is filled into the sample chamber 31 provided in the sample containers 30a and 30b, and this is set in a momentum trap (iron block) 32a.

The material for the sample containers 30a, 30b can be selected from a wide range of materials depending on the target grindstone material, but iron, brass, copper, and stainless steel are generally suitable from the cost standpoint.

The upper part of FIG. 5 shows the explosive configuration of this device. A conical explosive lens 28 is detonated by the detonator 18 at its apex, and the combustion in the explosive lens 28 is carried out downward in a plane. It is designed to be propagated in the direction.

Furthermore, the planar combustion is propagated to the explosive 25 below, causing planar combustion of this explosive, and the detonation shock wave generated by the combustion accelerates the metal drive plate 29 below at a high speed. collides with the sample container 30a.

This collision generates a plane shock wave in the sample volume of 930 m, and the powder constituting the abrasive grain layer is compressed by impact. As a result, a self-heating reaction is started as in the case of the cylindrical method, and sintering of the abrasive grain layer occurs.

In the case of this plane wave method, as well as the cylindrical method, the sample container 3
A direct method in which the explosive 25 is placed in direct contact with 0a can also be used.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

[Effect] Explain along with the effects.

[Examples of the Invention] (Examples 1 to 341 See Figures) Alumina powder with an average abrasive grain of 5 μm was added to a powder obtained by equally mixing titanium powder with an average particle size of 10 μl and amorphous carbon powder with an average particle size of 0.5 μm. They were mixed in a volume ratio of 4=1 to prepare a starting material for the binder component.

Further, diamond powder having an average particle size of 100 μm was mixed with this mixed powder at a volume ratio of 4:1 to obtain a starting material for the abrasive layer constituents. From this powder, a molded body having an outer diameter of 100 saφ and a thickness of 5 mm was obtained, having an aluminum base metal of sOl■φ×5-11 as a grinding wheel base metal in the center.

The abrasive layer constituent powder 1 with the aluminum grinding wheel base 2 is placed on the heat-resistant brick 3 of the apparatus shown in FIG. After the atmosphere was replaced with argon, a tungsten wire 4 was placed 1ssllll above the abrasive layer constituent powder 1.
was energized to make it red hot, heating a part of the powder 1 constituting the abrasive grain layer, igniting it, and starting a reaction.

The reaction proceeded uniformly over the entire powder 1 constituting the abrasive layer around the grinding wheel base 2, and after the reaction was completed, a grinding wheel material in which the abrasive layer was firmly bonded to the aluminum base was obtained.

When the constituent components of the binder in the abrasive grain layer of the obtained grinding wheel were investigated by X-ray diffraction analysis, it was found that T, which is a reaction product with alumina,
It consisted of an IC.

Next, a part of this abrasive grain layer was polished and its structure was observed with an optical microscope. It was found that fine TIC particles generated by the reaction surrounded the diamond particles in the 10θμ layer, and there were gaps between the diamond particles and these particles. No cracks were observed, and a tight adhesive state was obtained.

The bonding material part has a structure in which alumina particles and pores of several microns to several hundred microns are uniformly dispersed between several microns of TIC, which is a reaction product, and the porosity of this abrasive layer is Approximately 2
It was 5%.

Next, the upper and lower surfaces of the sintered disc-shaped grinding wheel material with this aluminum base metal were lightly polished with coarse grains of StC to balance the upper and lower surfaces, and a center hole was drilled in the aluminum base metal. After adjusting the grinding wheel balance and truing, a grinding wheel that can be used for grinding tests was obtained.

For comparison with this whetstone, we also used diamond powder of 100 μm and glass frit with a particle size of 1 μm or less in a volume ratio of 4:! After blending and mixing to give the following results, using the same aluminum base metal as the above-mentioned whetstone, it was fired at 1050 tons to create a whetstone having the same shape and size as the above-mentioned whetstone.

Note that the porosity of this grindstone was about 25%.

A grindstone for a grinding test was made from this grindstone material in the same manner as the above-mentioned grindstone.

The grinding performance of these two whetstones is 100% as a rigid material.
Using sintered alumina in the form of a flat plate measuring 200 as x 20 mm, the amount of diameter wear of each grindstone on the trunk was measured when the amount of grinding under certain conditions reached 25 cc, and the amount of wear was evaluated.

The grinding test conditions were: peripheral speed 1500■/■1n, table feed Q 10s/sIn, horizontal feed 2s+m, and depth of cut 0.0.
5 mm, wet type.

As a result, in the case of the grindstone according to the present invention, the wear amount of the grindstone diameter was 55 μm when the grinding amount was 25 cc.

On the other hand, the amount of wear in the case of the grindstone for specific tightening reached 275 μm, which is nearly five times that in the case of the grindstone according to the present invention, and the wear resistance was significantly inferior.

There was no difference in sound during grinding between the grindstone of the present invention and the comparative grindstone.

(See Example 2 to Figure 1) Aluminum (^l) powder with an average particle size of 5 μm and an average particle size of 5 μm
Tantalum carbon/nitride (Ta(CN)') powder was blended and mixed in a volume ratio with Conil to obtain a starting raw material powder for a binder component.

On the other hand, CBN powder with joO~150 μs and 20~40 μs
IIBN powder of μm was blended and mixed at a ratio of l=1 to obtain a superabrasive powder.

Next, the starting raw material powder of the binder component described above and the superabrasive grain constituent powder were blended and mixed in a volume ratio of 3=2 to obtain an abrasive layer constituent powder.

From this powder, a molded integral body having an aluminum base metal in the center and having an outer diameter of 100 m5+ and a thickness of 5 mm was produced using the same method as in Example 1.

This abrasive grain N component powder 1 attached to the aluminum alloy grinding wheel base 2 was placed on the heat-resistant brick 3 of the apparatus shown in FIG. 1, and after replacing the atmosphere with nitrogen, the same method as in Example 1 was used. , the tungsten wire 4 is energized, and the abrasive layer constituting powder l
A portion of it was heated and ignited.

After the reaction was completed, the abrasive material in which the abrasive grain layer was bonded to the aluminum alloy was taken out, and the powder constituting the abrasive grain layer and its structure were examined in the same manner as in Example 1.

As a result, the abrasive layer was composed of CN and the reaction product ^IN, and no AI was detected.

In addition, in the structure observation, Ta (CM) and the reaction product ^IN
A uniform structure in which M CON and WBN were firmly bound together was observed, and it was found that the bond between the binder and the abrasive grains was sufficiently strong.

Moreover, the porosity in the grindstone obtained here was 23%.

The upper and lower surfaces of this grindstone material were polished by the same method as in Example 1, and then a grindstone for a grinding test was produced.

For comparison, CBN% 111N powder similar to this example was used, and superabrasive powder mixed at the same ratio was used.
: A grinding wheel material having the same shape and dimensions as in this example was obtained by hot pressing a powder containing 60% by volume of low melting point glass frit using the same aluminum base metal as in this example.

The porosity of this grindstone was 23%, the same as in this example.

Next, the grinding performance of these two grindstones was evaluated using the same surface grinding method as the actual weight bias.

Here, the work material is high-speed steel 5 hardened to HRc@S.
Using a flat plate of IIH-3, it was set at a circumferential speed of 12SO*/mi.
n, table feed Iss/mln, horizontal feed 21m,'
Surface grinding was carried out under conditions of a depth of cut of 0.1-mm, and when the amount of grinding reached 5 Occ, the diameter wear amount of the carp grindstone was measured, and the performance was evaluated from the wear amount.

The grindstone diameter wear amount during 50cc grinding of the grindstone according to the present invention was 43 μm, and the amount of grinding was also not abnormal.

On the other hand, the grindstone prepared for comparison had a larger amount of grinding than at the beginning of grinding, and the test was stopped midway because a pattern like grinding burn began to appear on the grinding surface.

In addition, in the figure, 5 is an insulating tube, 7 is a power supply, and 8 is an O-ring.

(See Example 3 to Figure 2) Titanium (TI) powder with an average particle size of 10μ and an average particle size of 0.
Amorphous carbon powder with an average particle size of 5 μm and amorphous boron powder with an average particle size of 1 μm were blended and mixed at a molar ratio of 2:2:1 to obtain a starting material powder for the binder component. .

Next, this powder and diamond powder having an average particle size of 150 μm were blended and mixed at a volume ratio of 5:1 to obtain an abrasive layer constituting powder.

Raise the pressure ram 16 shown in FIG.
With a raised above the mold 11, first set the inner diameter to 49.9.
A grindstone base metal 2 made of aluminum alloy with a diameter of φ and a thickness of 10 mm is placed on the lower push rod 13b, and after filling the abrasive layer constituent powder 1 thereon, the upper push rod 13a is lowered and the grinding wheel base 2 is placed on the lower push rod 13b. Pressure ram 16't'' was pressurized to about 50 MPa.

Next, the upper and lower push rods made of graphite are 13m long.

A direct current of aOO^ and 70
Alternating currents of 0^ and 5OOHx were simultaneously flowed for about 10 seconds to initiate a reaction between titanium, carbon, and borax.

Immediately after the start of the reaction, both direct current and alternating current were turned off to prevent further temperature rise. After a few seconds, the reaction was completed, and a grinding wheel material was obtained in which the abrasive grain layer was firmly bonded to the aluminum alloy grinding wheel base.

When the constituent components of this abrasive grain layer were examined by X-ray diffraction, they were found to be TIC and TIB! , no metal TI was detected, and
No reverse conversion of diamond to the low-pressure phase was also observed.

Next, the upper and lower surfaces of this whetstone material were lightly polished to balance the upper and lower surfaces, and then used as a rotating whetstone.

When a small piece of silicon nitride sintered body was polished using one set of this grindstone, there was no abnormal amount of grinding, and the grinding state was good.

In addition, in the figure, 12 is an insulating material cylinder, 4 is an insulating sheet, 1
5 is a pedestal, and 17 is a mold support ring.

(Refer to Example 4 to Figure 3) The molar ratio of titanium oxide (T102) powder with an average particle size of 20μ, amorphous carbon powder with an average particle size of 0.5μI, and aluminum powder with an average particle size of 10μ is 3. :3:4 and mixed.

Furthermore, this mixed powder and MgO50 with an average abrasive grain of 5μ
Powder consisting of 50 volume % of 5IOt having an average particle size of 7 μm was blended and mixed at a volume ratio of 1:3 to obtain a starting material for a binder component.

Next, superabrasive powder consisting of 50 volume% of CBN powder with an average particle size of 100 μm and 50 volume% of diamond powder with an average particle diameter of 100 μm is added to this powder to give a mixing ratio of 20 volume%, and the starting material powder for the grinding wheel is added to the powder. Obtained.

This powder was subjected to impact compression using an impact compression device of the type shown in FIG. 3 without a center rod 24.

Here, the inner diameter is 50 m, the height is 50 m, and the wall thickness is 3.2 m.
A cylindrical sample container 22 made of iron was used, and powder of the abrasive layer structure was filled therein so that the initial relative density was 55%.

Again, explosion! Eight NFG was used as 1125, and this ANFO was filled on the outside of the cylindrical sample container 22 so that the thickness in the radial direction was 40 mm, and it was detonated to impact-compress the powder constituting the abrasive grain layer.

After the impact treatment, the outer iron cylindrical part of the sample was removed by cutting, and when a part of the grinding wheel material was exposed, the surface was further prepared using a SIG grinding wheel, and then balanced.
After truing, it was made into a whetstone with a diameter of 45φ.

When this grindstone was used to grind the inner diameter of a cylindrical alumina sintered body having an inner diameter of 2001 mm and an outer diameter of 240 mm, it showed good grinding performance with low grinding resistance.

The binder components of this abrasive grain layer are MgO and StO.

In addition, Ding IC and Hachi produced by the reaction! , O5, and no metal Al was observed.

Furthermore, the porosity of this grindstone was somewhat high at 32%.

(Refer to Example 5 to Figure 3) In Example 1, the alumina powder portion of the starting materials for the binder component was divided into wcso volume % and NbN50 volume %.
Example except that it was replaced with a mixed powder of The starting materials having the same abrasive layer constituents were used and subjected to impact compression using the impact compression apparatus shown in FIG.

Here, an aluminum alloy round bar with an outer diameter of 90mm is used as a medium bar,
24, and as the cylindrical sample container 22, an iron cylinder with an inner diameter of foam 2 and a wall thickness of 41 mm was used.

A thin cylindrical space formed by the inner rod 24 and the cylindrical sample container 22 outside thereof was filled with the abrasive layer constituent powder so that the initial relative density was 60%.

ANF'Q was used as the explosive 25 and filled so that the thickness in the radial direction was SO+*s, which was detonated with the detonator 18 and compressed by impact. And the aluminum alloy inner rod 24
A cylindrical grinding wheel material with .

Next, a disk-shaped grindstone material with a thickness of 5 mm was cut from this round bar, a shaft hole was provided in the center, and the grindstone was balanced and trued to produce a rotary grindstone.

Using this grindstone, the grinding performance of the grindstone was evaluated in the same manner as in Example 1.

As a result, the grinding wheel diameter wear amount with a grinding amount of 25cc is 53
It was μ theory. The binding material component of this grinding wheel is WClN
bN and TiC, which is a reaction product.

The porosity of this whetstone was 18%.

In the figure, 19 is an upper plate, 20a is a plug, 20b is a plug, 21 is an explosive container, 23 is a lower plate, 26 is a drive tube, and 27 is a space.

(See Example 6 to Figure 5) Mo01 powder with an average particle size of 10 μm, ^I powder with an average particle size of 10 μm, and silicon powder with an average particle size of 5 μm in a molar ratio of 1:2.
:2 was blended and mixed.

Further, this powder, 10% by volume of Zr511 powder having an average particle size of 1 Gμm, and 3 parts of TaN powder having an average particle size of 10 μm were blended in a ratio of 2=1 and mixed to obtain a starting raw material powder for a binder component.

Next, this powder and impact synthetic diamond powder having a particle size of lθ to 20 μm were blended at a volume ratio of 2:1 and mixed to obtain an abrasive layer-constituting powder.

This powder was impact compressed using a planar shock wave generator shown in FIG.

Sample container 30a in FIG. 30b is made of iron, with an outer diameter of 49.91-1 and a thickness of 10 in the sample chamber with an inner diameter of 50-1.
The aluminum alloy disk of the intestine and the powder constituting the abrasive grain layer were stacked and arranged.

The thickness of the abrasive grain layer here was approximately 51, and the relative packing density thereof was 60%.

Shock compression was performed by colliding the lower sample container 3Oa with a drive plate 29 made of iron with a thickness of 3.2 mm accelerated by a plane detonation wave obtained using an explosive lens 28.

After impact treatment, iron sample container 30a.

30b was removed by cutting, and the sample was recovered with the abrasive grain layer firmly bonded to the aluminum alloy grindstone base metal.

As a result of X-ray diffraction, the bonding material of this grindstone was found to be ZrSi2, TaH, and MoSi.
,AI,0,.

Also, the porosity of this whetstone is %22%. there were.

This grindstone material was processed in the same manner as in Example 3 to form a rotary grindstone, and when a small piece of the CON sintered body was polished using this grindstone, a good grinding state was obtained.

In addition, in the figure, 31 is a momentum trap for the sample 132a, and 32b is a momentum trap.

[Effects of the Invention] As detailed above, the present invention provides superabrasive powder with (a) a component consisting of at least one of metal carbides, nitrides, borides, oxides, silicides, or solid solutions thereof; (b) Carbides, nitrides, borides, oxides,
When blending components that produce at least one type of silicide or solid solution thereof, blending so that the volume percent of component (b) is 20% or more of the remaining starting material composition excluding superabrasive grains. , is characterized by molding the mixed powder and heating a part or the whole of it to initiate and advance a self-heating reaction, and sintering the powder constituting the abrasive layer containing superabrasive grains. A superabrasive grinding wheel containing 5% by volume or more and less than 60% by volume, with the remaining binder phase consisting of carbides, nitrides, borides, oxides, silicides, or at least one of these solid solutions and pores, is a simple method. It can be manufactured using equipment and means.

The superabrasive grindstone according to the present invention is suitable for high-precision, high-efficiency machining of high-hardness hardened steel and high-hardness ceramic materials.

[Brief explanation of the drawing]

Figure 1 is a schematic vertical cross-sectional view of a grindstone manufacturing device using heating wires, Figure 2 is a schematic vertical cross-sectional view of a grindstone manufacturing device using electric discharge, and Figures 3 and 4 are cylindrical impact compression. FIG. 5 is a schematic longitudinal sectional view of a planar impact compression device. 111. Abrasive grain layer constituent powder, 206. Whetstone base metal, 310. Heat-resistant brick, 401. Tungsten wire 610. container, 910. Gas replacement valve, 10, vacuum evacuation valve, 11, mold, 13a. ,,upper push rod, 13b. ,,lower push rod, 16,,,pressure ram, 18. 22. 24. 25. 28. 29. 30m. , detonator 1, cylindrical sample container, middle rod 1, explosive m%, explosive lens 1, drive plate, 30 m), ,, sample container. Figure 5 Procedural amendment January 1, 1999 Name of the invention Super abrasive grindstone and relation to the case of the person amending its manufacturing method Patent applicant name Sumitomo Coal Mining Co., Ltd. Agent Address 060 Address Sapporo City Center Kita 1-jo Nishi 3-3-3 Chest, 7 Esther Building Claims column Detailed description of the invention column Shift Contents of the amendment (1) Claims from page 1, line 5 on page 3 to line 15 on page 3 of the specification amend it to legal text. "1. Contains 5% by volume or more and less than 60% by volume of superabrasive grains,
The remaining binder phase is a carbide, nitride, boride, oxide, silicide, or a solid solution thereof.
A superabrasive grindstone characterized by comprising 90% by volume and 10 to 50% by volume of pores. 2. The superabrasive grindstone according to claim 1, wherein the superabrasive grains are composed of at least 1 fl of diamond, cubic boron nitride, or wurtzite boron nitride. 3. The superabrasive powder contains (a) a component consisting of at least one of metal carbides, nitrides, borides, oxides, silicides, or solid solutions thereof, and (b) carbides, nitrides, and borides by a self-heating reaction. monster,
At least one of an oxide, a silicide, or a solid solution thereof
The following ingredients that produce rice: a) Metal powder B) Mixed powder of metal powder and carbon powder) Mixed powder of metal powder and boron powder bundle 2) Mixed powder of metal powder, carbon powder, and boron powder bundle To mixed powder of metal powder, carbon powder and metal oxide powder) To mixed powder of metal powder, boron powder bundle and metal oxide powder To) Mixed powder of metal powder, carbon powder, boron powder bundle and metal oxide powder h) When blending the mixed powder of metal powder, silicon powder, and metal oxide powder, component (b) that participates in a self-heating reaction.
After molding the abrasive layer constituting powder, which is blended and mixed so that the volume percent of the starting material composition is 20% or more after excluding the superabrasive grains, or during molding, part or all of the molded body is By heating and initiating and advancing a self-heating reaction,
Characterized by sintering a powder constituting an abrasive layer containing superabrasive grains.Contains 5% by volume or more but once less than 5% by volume of superabrasive grains, and the remaining binder phase is a carbide, nitride, boride, or oxide. , a method for producing a superabrasive grindstone characterized by comprising at least 1 fi of 50 to 90 volume % of silicides and solid solutions thereof and 10 to 50 volume % of pores. 4. The method for producing a superabrasive grindstone according to claim 3, wherein the self-heating reaction is initiated and progressed by impact-compressing the powder constituting the abrasive layer or its compact. 5. The method for producing a superabrasive grindstone according to claim 3, wherein a self-heating reaction is initiated and progressed by heating the abrasive layer-constituting powder or its compact by applying electricity." Correct "50" to "60". (3) Correct to "Cylindrical shock wave compression device" and "Cylindrical shock compression device" on page 30, line 9 of the specification. (4) "rt1 impact compression device" on page 43, line 19 and page 45, line 8 of the specification is corrected to "cylindrical impact compression device." (5) "Wave generator" on page 4, lines 10 to 11 of the specification is referred to as a "plane impact compression device." “More than compensating for flat impact.

Claims (1)

[Claims] 1. Contains 5% by volume or more and less than 60% by volume of superabrasive grains, and the remaining binder phase is at least one of carbides, nitrides, borides, oxides, silicides, or solid solutions thereof. Seeds 50-90
% by volume and pores of 10 to 50% by volume. 2. The superabrasive grindstone according to claim 1, wherein the superabrasive grains are made of at least one of diamond, cubic boron nitride, and wurtzite boron nitride. 3. The superabrasive powder contains (a) a component consisting of at least one of metal carbides, nitrides, borides, oxides, silicides, or solid solutions thereof, and (b) carbides, nitrides, and borides by a self-heating reaction. monster,
At least one of an oxide, a silicide, or a solid solution thereof
A) Metal powder B) Mixed powder of metal powder and carbon powder C) Mixed powder of metal powder and boron powder D) Mixed powder of metal powder, carbon powder and boron powder E) Metal Mixed powder of powder, carbon powder and metal oxide powder F) Mixed powder of metal powder, boron powder and metal oxide powder G) Mixed powder of metal powder, carbon powder, boron powder and metal oxide powder C) Metal When blending the mixed powder of the powder, silicon powder, and metal oxide powder, the volume percent of the component (b) that participates in the self-heating reaction is 20% or more of the remaining starting material composition excluding the superabrasive grains. After molding the abrasive layer composition powder blended and mixed as described above, or during molding, a part or the whole of the compact is heated to initiate and advance a self-heating reaction, thereby forming an abrasive layer composition containing superabrasive grains. Contains 5% by volume or more and less than 50% by volume of superabrasive grains characterized by sintering powder, and the remaining binder phase is at least one of carbides, nitrides, borides, oxides, silicides, and solid solutions thereof. A method for producing a superabrasive grindstone characterized by comprising 50-90% by volume of seeds and 10-50% by volume of pores. 4. The method for producing a superabrasive grindstone according to claim 3, wherein the self-heating reaction is initiated and progressed by impact-compressing the powder constituting the abrasive layer or its compact. 5. The method for producing a superabrasive grindstone according to claim 3, wherein the self-heating reaction is initiated and progressed by heating the abrasive layer constituting powder or its molded product by applying electricity.