JPH08108369A - Grinding wheel tool and its manufacture - Google Patents

Abstract

PURPOSE: To provide a grinding wheel tool which is excellent in the cutting quality of an abrasive grain and is excellent in holding performance of the abrasive grain and capable of forming the plural layer distribution of the abrasive grain and cutting concrete and stone or the like without requiring cooling water, and its manufacturing method which is excellent in productivity. CONSTITUTION: An organic paste agent is applied to a base material on which blast processing is performed, and powder of a mixture of self-fluxing alloy powder or self-fluxing alloy and transition metal or transition metal alloy is sprayed on this organic paste agent as a binding agent, and the organic paste agent is dried, and after organic paste agent is reapplied, an abrasive grain by a diamond particle or a cubic crystal boron nitride particle is sprayed. After this organic paste agent is dried, it is heated to a temperature of 900 to 1150 deg.C in a nonoxidating atmosphere such as a vacuum atmosphere, and the binding agent is fused, and the abrasive grain is fixed to the base material, and this is annealed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grindstone tool such as a diamond tool used for grinding and a method for producing the same, and more particularly to a method for firmly bonding abrasive grains to a substrate by a self-fluxing alloy or the like.

[0002]

2. Description of the Related Art As a general method for forming a grindstone in a grindstone tool using diamond particles or cubic boron nitride particles as abrasive grains, there are an electrodeposition bonding method and a metal sinter bonding method.

In the former electrodeposition bonding method, for example, a steel substrate is used as a material to be plated, a non-plated portion is masked with a resist for plating, nickel plating is applied to the base material, and then a surfactant is used to polish a predetermined amount. This is a method in which electroplating is performed using a nickel plating solution in which a dispersion liquid in which particles are dispersed is mixed and the eutectoid particles to be co-deposited are fixed with electrodeposited nickel.

In the latter metal-sinter bonding method, for example, abrasive grains and cobalt powder or mixed powder of cobalt, copper and tin, etc. are mixed and kept at a temperature of 900 to 1000 ° C. in a nitrogen atmosphere while maintaining a pressure of 250 kg /. By a so-called hot pressing method in which a pressure of cm ² is applied, the above-mentioned metal powder is powder-sintered to form a sintered chip with abrasive grains fixed, and the sintered chip is brazed or laser-welded to form a steel base material. It is a method of attaching to.

[0005]

However, most of the abrasive grains except a part of natural diamond are insulating,
In the former electrodeposition bonding method using diamond particles, as shown in FIG. 3, the diamond particles 5 are held on the steel base material 6 by the electrodeposited metal 7, and between the diamond particles 5 there is no electrodeposition. The deposited metal 7 shows swelling, but the adhesion of the electrodeposited metal 7 to the diamond particles 5 is poor, and the so-called poor wetting state occurs. Therefore, the diamond particles 5 substantially depend on the holding force of the electrodeposited metal 7. become. Therefore, although the sharpness during use is good depending on the exposed condition of the cutting edge of the diamond particles, the holding power of the diamond particles is weak, and especially when grinding, there is thermal expansion of the electrodeposited metal such as nickel due to generated heat Since loosening occurs in the fixing of the particles and the diamond particles are likely to fall off, wet grinding using cooling water is necessary, and it may still be difficult to handle depending on the material to be ground,
There is also a problem that the tool life is short. Furthermore, this electrodeposition method has a problem that the arrangement of diamond particles is limited to a single layer.

Further, in the latter sinter-bonding method by hot pressing using diamond particles, the diamond particles can be held in multiple layers in the sintered metal,
The wettability between the sintered metal and the diamond particles is poor, and similar to the case of the electrodeposition bonding method shown in FIG.
Since the retention of diamond particles depends on the holding force due to the shrinkage and internal strain of the surrounding sintered metal, the retention force is weak, wet grinding is necessary, and the utilization efficiency of diamond particles is poor. In addition, there is a problem that productivity cannot be obtained because it cannot be directly formed on the substrate.

The cubic boron nitride particles as abrasive grains also have a very high melting point, but they are electrically insulating and have poor adhesion of electrodeposited metal, and have a low coefficient of thermal expansion. Since it had poor wettability, it had the same problem as in the case of the above diamond particles.

In view of such a situation, the present invention has good sharpness of the abrasive grains, good retention of the abrasive grains, is capable of forming a multi-layer distribution of the abrasive grains, and is not limited to the kind of the material to be ground. An object of the present invention is to provide a grindstone tool capable of dry grinding that does not require cooling water and a method of manufacturing a grindstone tool with high productivity.

[0009]

In order to achieve the above-mentioned object, the present invention applies an organic sizing agent to a blasted base material, and a self-fluxing alloy powder as a binder on the organic sizing agent. After spraying, the organic sizing agent is dried, the organic sizing agent is applied again, and after spraying diamond particles as abrasive grains,
The organic paste is dried, then heated to a temperature of 900 to 1150 ° C. in a non-oxidizing atmosphere, and the abrasive grains are fixed to the base material by fusion bonding of the binder, followed by gradual cooling. And a method of manufacturing a grindstone tool using cubic boron nitride particles as the abrasive grains, wherein the self-fluxing alloy contains 10% chromium by weight.
~ 20%, 2-5% silicon, 2-5% boron, 2 copper
-4%, molybdenum 2-4%, tungsten 2-4
%, Carbon 0.3 to 1.0% and iron 5% or less, and the balance is a nickel-based self-fluxing alloy of nickel, wherein the self-fluxing alloy is% by weight. so,
Chromium 10-20%, Silicon 2-5%, Boron 2-2
5%, 2-4% of copper, 2-4% of molybdenum, 2-4% of tungsten, 0.3-1.0% of carbon, 5% or less of iron and 10-20% of nickel, and the rest Is a cobalt-based self-fluxing alloy of cobalt, and a powder of a mixture containing a transition metal as a binder in an amount of less than 50% by weight and the balance being a self-fluxing alloy. Or a method for producing a grindstone tool using a powder of a mixture containing a transition metal alloy in an amount of less than 50% by weight and the remainder being a self-fluxing alloy, as the binder. And the non-oxidizing atmosphere is 1 ×
A method for producing a grindstone tool in a vacuum of 10 ^{−4 to} 5 × 10 ⁻⁴ torr, or a method for producing a grindstone tool in which the non-oxidizing atmosphere is an argon gas atmosphere, or the non-oxidizing method. The present invention proposes a method for manufacturing a grindstone tool in which the characteristic atmosphere is a hydrogen gas atmosphere, and also a grindstone tool obtained by these manufacturing methods.

[0010]

According to the above steps, by applying a binder such as self-fluxing alloy powder and abrasive grains such as diamond particles to the blasted base material through an organic sizing agent and heating at high temperature,
The bonding material fuses to the base material and also to the abrasive grains in a fluidly wet state.

The surface of the base material is cleaned and activated by the blasting treatment, and the anchoring effect improves the adhesion of the organic sizing agent and the binder. The water-soluble organic sizing agent adheres and holds the abrasive grains, volatilizes by heating at about 500 ° C. or higher, and at the same time, causes the bonding material to be substituted and adhered to the abrasive grains. As the organic sizing agent, methyl cellulose, cellulose ether such as hydroxypropylmethyl cellulose or hydroxyethyl methyl cellulose exhibits high viscosity and high elasticity according to its dilution concentration, and the workability in the method of the present invention is good and the retention of abrasive grains is high. It is good.

Oxygen is harmful when the fusion material such as a self-fluxing alloy is heated for fusion, and the presence of a slight amount of oxygen oxidizes the surface of the abrasive grains. In the case of diamond particles, graphitization is further promoted and fusion is caused. Be hindered. In order to prevent this, it is also effective to introduce an argon gas or hydrogen gas to create a non-oxidizing atmosphere, but in this case, in particular, when introducing substitution,
By interposing a vacuum suction step and avoiding oxygen from remaining as much as possible, the effect after fusion heating is further improved.
When a vacuum atmosphere is used as the non-oxidizing atmosphere, a high degree of vacuum of 1 × 10 ^{−4 to} 5 × 10 ⁻⁴ torr is preferable, and when the degree of vacuum is lower than this range, the abrasive grains are prevented from being oxidized. It is insufficient, and the effect is not so different even if the degree of vacuum is higher than this range.

When the fusion heating temperature is less than 900 ° C., the fusion between the binder such as self-fluxing alloy powder and the abrasive grains is insufficient and the holding power of the abrasive grains is poor, and when it exceeds 1150 ° C., the liquid phase is formed. The excessive flow of the binder deteriorates the state of holding the abrasive grains, and the embrittlement of the abrasive grains begins due to oxidation. For diamond particles,
Furthermore, when the base material contains iron, the iron and the carbon of the diamond particles react with each other, and brittle cementite is likely to be generated, which may make it unusable as a diamond tool.

A grindstone tool that has completed the fusion heating will be distorted when used as a product when it is rapidly cooled in the cooling process, and may distort when used as a product. Cool the furnace in a non-oxidizing atmosphere.

The self-fluxing alloy is a general term for wear-resistant thermal spraying alloys mainly composed of nickel-chromium-silicon-boron or cobalt-nickel-chromium-silicon-boron. Available. Chromium in this self-fluxing alloy improves hardness and wear resistance by combination with nickel and / or cobalt, but in the present invention, in particular, chemical reactivity with abrasive grains is improved to improve wettability. Is meaningful to. If chromium is less than 10%, these effects cannot be expected so much, and if it exceeds 20%, improvement of these effects cannot be expected. Silicon and boron, whose oxides generated by heating act as a flux, lower the melting point of the molten alloy, increase the fluidity, and improve the wettability and fusion property to the abrasive grains. % Or less, the effect is small, and even if it is 5% or more, improvement of the effect cannot be expected.

In the present invention, a self-fluxing alloy containing copper, molybdenum and tungsten is preferably used. Copper in this self-fluxing alloy has the effect of lowering the melting point of the molten alloy and improving the wettability of the abrasive grains, and molybdenum is dispersed as an aggregate during the fusion heating to form a liquid phase self-fluxing alloy. Prevents excessive flow and prevents movement of abrasive grains. Further, molybdenum in this self-fluxing alloy exhibits a lubricating action when this grindstone tool product is used, and exhibits an effect as an active filler. If the content of each of copper and molybdenum is less than 2%, the effect cannot be expected. Even if the content of each of copper and molybdenum is more than 5%, the effect cannot be expected to be improved as much as the addition thereof.

Tungsten in this self-fluxing alloy exhibits an effective improvement in wear resistance within the above-mentioned range of components, and iron and carbon often enter as impurities, but this carbon forms a compound with chromium. It also has the function of finely dispersing in the casting alloy to improve the strength. Cobalt also has an effect of improving not only the wear resistance of the alloy but also the heat resistance within the above-mentioned range of components, and is advantageous for a difficult-to-grind material having a relatively high heat generation.

Then, by using a powder of a mixture of the self-fluxing alloy and a transition metal or an alloy of transition metals of less than 50% by weight as the binder, the binder is hardly impaired, and the binder is further reduced. The melting point can be lowered and the internal stress due to the self-fluxing alloy can be relaxed, and in the grindstone manufacturing process, the abrasive grains due to the diamond particles or the cubic boron nitride particles can be fixed and held without being damaged.
The transition metals include titanium, manganese, iron, zirconium, molybdenum and the like, atomic numbers 21 to 28 and 39 to 46.
It is a high melting point solid metal.

[0019]

EXAMPLES A method for manufacturing a grindstone tool according to the present invention will be described below in the case of a diamond tool with reference to an example according to the process chart of FIG. 10 made of alloy tool steel as the base material
Using a steel base material for cutters with a cm diameter,
Alumina abrasive grains of the mesh were blown at a pressure of 6 kg / cm ² for 5 minutes for blasting to clean the surface. An organic sizing agent prepared by diluting commercially available water-soluble methylcellulose with about 3.3 times the amount of water was applied to this steel base material, and 16% by weight of chromium was added as a self-fluxing alloy powder on it.
4.0% silicon, 4.0% boron, 4.0% iron,
A pre-alloyed commercial atomized powder of a nickel-based self-fluxing alloy containing 2.4% copper, 2.4% molybdenum, 2.4% tungsten, and 0.5% carbon with the balance being nickel. Was sprayed through a filter, and after spraying, this was kept at 80 ° C. for 10 minutes to dry the organic sizing agent. By this drying, the vacuum degree at the time of fusion heating is kept good.

Then, after applying the organic paste again,
1 carat (0.2 g) of 40-50 mesh diamond particles was sprayed, the protruding state was adjusted by pressing, and the organic sizing agent was dried at 80 ° C. for 10 minutes and 150 ° C. for 20 minutes. It should be noted that performing the drying in two steps has the meaning of avoiding rapid boiling of water in the organic sizing agent. The state of holding the diamond particles at this time is shown in FIG. That is, the self-fluxing alloy powder 2A is spread on the blasted steel base material 1, and the diamond particles 4 are held on the self-fluxing alloy powder 2A via the organic sizing agent 3. The self-fluxing alloy powder 2 is infiltrated with an organic sizing agent.

The degree of vacuum in the heat treatment furnace is set to 3 × 10 ^-4 torr.
r, and heated to 870 ° C. in about 7 hours to sufficiently volatilize and remove the organic sizing agent. Then, the composition is maintained at 870 ° C. for 1 hour to stabilize the composition of the self-fluxing alloy, and further, about 1
The temperature was raised to 1100 ° C. in 5 minutes and kept for 10 to 15 minutes. After that, gradual cooling was performed in a vacuum atmosphere in a heat treatment furnace to cool to room temperature to obtain a diamond tool, that is, a cutter sample in which diamond particles were held in a single layer, as shown in FIG. 2 (b). That is, the self-fluxing alloy 2B is fused to the steel base material 1, wets the diamond particles 4 in a rising shape, and is chemically bonded or fused to the diamond particles 4.

The cutter sample thus obtained was
It was attached to a grinding tool (sander) and subjected to a grinding test.
That is, this grinding tool is attached to a test device, and a grinding tool with a 5 kg weight slides along a guide that descends obliquely so that the cutter portion is loaded on the material to be ground in a natural falling state. Prepare 30 cuts for each of the stones made of concrete and red granite,
Grinding was performed in a dry state without using cooling water, and the grinding speed was investigated. In addition, the cuttability of 30-cut crystallized glass was investigated by the same method. The stone material and the crystallized glass are each 20 mm thick and 300 mm long.

Cutter samples of the same size were manufactured by the above-mentioned conventional electrodeposition bonding method and metal sinter bonding method to form Conventional Example 1 and Conventional Example 2, and the cutters of the examples manufactured by the above-mentioned method of the present invention. A grinding test was performed in the same manner as the sample. The results are shown in Table 1.

[0024]

[Table 1]

The cutter sample according to the present invention is about twice as large as that of the conventional electrodeposition bonding method and about 1.5 times as much as that of the metal sinter bonding method for concrete and stone.
It showed sharpness that can be ground at double the grinding speed, and showed that the crystallized glass also had a cutting ability 4 to 6 times that of the conventional method.

Next, a diamond bit sample having an inner diameter of 20 mm was manufactured. The procedure was the same as for the cutter sample, except that diamond particles of 40 to 50 mesh were applied in a total amount of 1.5 carats.

25k of the manufactured diamond bit sample
It was attached to an electric drill tool equipped with a weight of g, and in a free fall state, a drilling test by grinding was performed in a dry specification without using cooling water. 10 for reinforced concrete material as perforated material
A 80 mm thick drainage mast lid with mm diameter rebar was used, and 30 mm thick red granite was used as the stone material, and 12 holes were drilled for the reinforced concrete material and 20 holes were drilled for the stone material.

Diamond bit samples having the same substrate size as those of the diamond bit samples according to the above-mentioned embodiments were manufactured by the above-mentioned electrodeposition bonding method and sintered metal bonding method, respectively. The same test was performed as No. 2. The results are shown in Table 2.

[0029]

[Table 2]

The diamond bit sample according to the present invention comprises:
It shows that there is no abnormality even if 12 holes are drilled in reinforced concrete material, and that it has at least several times the drilling capacity compared to those using the conventional electrodeposition bonding method and metal sinter bonding method.
Even if stones were drilled with 20 holes, there was no abnormality,
A similar drilling ability could be expected.

As the base material in the grindstone tool of the present invention,
Carbon steel for machine structure (S45C etc.), tough steel (SCM
Etc.), carbon tool steel (SK etc.), alloy tool steel (SKS etc.)
Alternatively, a steel base material made of stainless steel (SUS) or the like and a cemented carbide base material made of tungsten carbide or titanium carbide can be selected and used according to the application.

The application range of the grindstone tool obtained by the manufacturing method of the present invention is wide, and it is not limited to the cutters and bits of the above-mentioned embodiments, but also to blades having a diameter of 9 inches or more, cup wheels, core bits, diamond wire saws, etc. It can be applied and can be used as an object to be ground, such as concrete, reinforced concrete, brick, stone, crystallized glass, building block, porcelain tile, roof tile, hard carbon, FRP,
It can be ground by a dry method without using any object such as metal and without using cooling water.

[0033]

As is apparent from the above description, according to the present invention, the following effects can be obtained. (1) A binder such as a self-fluxing alloy has a good wettability between the base material and the abrasive grains through the organic sizing agent, and because they bond by fusion, the retention force of the base material is strong and the durability of the tool is high. Is improved. (2) The retention of the abrasive grains is strong, and the amount of protrusion of the abrasive grains can be increased with a relatively small amount of the binder, so that a sharp cutting product can be produced. (3) Since the abrasive grains are sharp, less heat is generated and the heat resistance of the constituent materials such as the binder is good, and dry grinding can be performed without using cooling water regardless of the material to be ground. (4) The protrusion amount of the abrasive grains can be easily adjusted by adjusting the viscosity of the organic paste, adjusting the particle size and supply amount of the binder, and adjusting the pressure when applying the abrasive grains.

(5) Since the distribution of the abrasive grains at the time of manufacture can be arbitrarily performed, the distribution density of the abrasive grains can be arbitrarily adjusted. (6) During manufacturing, the abrasive grains and the binder can be temporarily fixed with an organic sizing agent, so masking is not required unlike the conventional electrodeposition bonding method. Further, since the abrasive grains can be directly placed on the base material, there is no need for a complicated process such as welding of a sintered tip unlike the metal sinter bonding method. (7) Therefore, the process is simple and the productivity is good. (8) Since the productivity is good, mass production is possible and products can be provided at low cost.

(9) Since the combination of the abrasive grains and the bonding material via the organic paste can be made into multiple layers, the abrasive grains can be arbitrarily arranged in a single layer or multiple layers. (10) Since the abrasive grains have good holding power and good sharpness, dry grinding is possible regardless of the type of object to be ground, and has a wide range of applications.

[Brief description of drawings]

FIG. 1 is a process drawing of the method of the present invention.

FIG. 2 is a partial schematic view showing a diamond particle holding state in a grindstone tool using diamond particles according to the manufacturing method of the present invention, where (a) is a state before a heating step, and (b) is a diagram.
[Fig. 3] is a schematic view showing a situation after a heating step.

FIG. 3 is a partial schematic view showing a state of holding diamond particles in a grindstone tool using diamond particles by a conventional electrodeposition bonding method.

[Explanation of symbols]

 1 Steel substrate 2A Self-fluxing alloy powder 2B Self-fluxing alloy 3 Organic sizing agent 4 Diamond particles

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B24D 3/00 320 B 340 C22C 19/05 BZ 19/07 Z

Claims (10)

[Claims] 1. An organic sizing agent is applied to a blasted base material, a powder of a self-fluxing alloy is spread as a binding material on the organic sizing agent, the organic sizing agent is dried, and the organic sizing agent is again used. After applying a sizing agent and spraying diamond particles as abrasive grains, the organic sizing agent is dried, and then heated to a temperature of 900 to 1150 ° C. in a non-oxidizing atmosphere to fuse the binder. A method for manufacturing a grindstone tool, characterized in that the abrasive grains are fixed to the base material and gradually cooled. 2. A method of manufacturing a grindstone tool according to claim 1, wherein cubic boron nitride particles are used as the abrasive grains. 3. The self-fluxing alloy contains 10% chromium by weight.
~ 20%, 2-5% silicon, 2-5% boron, 2 copper
-4%, molybdenum 2-4%, tungsten 2-4
%, Carbon 0.3 to 1.0% and iron 5% or less, and the balance is a nickel-based self-fluxing alloy of nickel, the method for manufacturing a grindstone tool according to claim 1 or 2. . 4. The self-fluxing alloy contains 10% chromium by weight.
~ 20%, 2-5% silicon, 2-5% boron, 2 copper
-4%, molybdenum 2-4%, tungsten 2-4
%, Carbon 0.3 to 1.0%, iron 5% or less and nickel 10 to 20%, the balance being a cobalt-based self-fluxing alloy of cobalt. A method for manufacturing the described grindstone tool. 5. The grindstone according to claim 1, wherein a powder of a mixture containing a transition metal in an amount of less than 50% by weight and the balance being a self-fluxing alloy is used as the binder. Tool manufacturing method. 6. A powder of a mixture containing an alloy of a transition metal in an amount of less than 50% by weight, the balance being a self-fluxing alloy, is used as the binder. Method for manufacturing whetstone tools. 7. The non-oxidizing atmosphere is 1 × 10 ^{−4 to} 5 × 1.
A vacuum of 0 ^-4 torr.
The method for manufacturing a grindstone tool according to claim 6. 8. The method for manufacturing a grindstone tool according to claim 1, wherein the non-oxidizing atmosphere is an argon gas atmosphere. 9. The method of manufacturing a grindstone tool according to claim 1, wherein the non-oxidizing atmosphere is a hydrogen gas atmosphere. 10. A grindstone tool obtained by the method for manufacturing a grindstone tool according to any one of claims 1 to 9.