JP2001047366A - Metal-coated abrasive grain, its manufacture, and resin- bond grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heighten the holding strength of abrasive grains. SOLUTION: The surfaces of super-abrasive grains 1 are covered with metal covering layers 11 consisting of copper, and a chemical agent such as Mech-Etch Bond (trade mark) is applied to the surface of each covering layer 11 followed by a chemical etching process so that a surface is formed where a number of micro-projections 11a remain. Thus metal-covered abrasive grains 10 are accomplished, and a resin-bond whetstone is produced of such a structure that metal-covered abrasive grains 10 are contained dispersively in a resin bond phase.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal-coated abrasive grain dispersed and fixed in a binder phase in a resin-bonded grinding wheel or the like, a method for producing the same, and a resin-bonded grinding wheel provided with the metal-coated abrasive grain.

[0002]

2. Description of the Related Art Conventionally, for example, a resin-bonded grindstone is prepared by mixing a raw material powder of a thermoplastic resin such as a phenol resin or an epoxy resin with superabrasive grains such as diamond or CBN, and forming the mixture alone or together with an alloy as required. After pressing, press forming and sintering to form a resin bond abrasive layer. Since the resin bond phase holding the superabrasive grains is relatively soft and low in strength, the resin-bonded grindstone wears off the tip of the superabrasive grains when grinding a relatively hard work material. Before the drop, the resin binder phase supporting the superabrasive grains is crushed, worn or deformed, and the superabrasive grains fall off. Resin-bonded whetstones tend to cause severe wear and to lose sharpness due to abrasive particles falling off. Therefore, in order to improve the holding power and heat resistance of the superabrasive grains in the resin binder phase, for example, FIG.
As shown in FIG. 1, a technique in which a metal such as copper or nickel is coated on the surface of superabrasive grains 1 by electroless plating or the like to form a metal coating layer 2 to form metal coated abrasive grains 3 is employed. FIG. 7 shows a resin-bonded grindstone using such metal-coated abrasive grains 3. In this resin-bonded grindstone 4, an abrasive layer 6 is mounted on a base metal 5, and the abrasive layer 6 is made of thermoplastic resin. The metal-coated abrasive grains 3 are dispersed and arranged in a resin bonding phase 7 made of a resin.

[0003]

By the way, when grinding with such a resin-bonded grinding wheel 4, light metal grinding can prevent the metal-coated abrasive grains 3 from falling off, but heavy grinding requires a large load. Metal coating abrasive grains 3 on the surface of the abrasive layer 6
And the heat generated was too high to sufficiently suppress the grinding heat. The present invention has been made in view of the above circumstances, and has a metal-coated abrasive grain capable of improving the heat resistance of the abrasive grain by improving the abrasive grain holding strength so as to withstand heavy grinding, a method of manufacturing the same, and a resin bond. The purpose is to provide a whetstone.

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems and achieve the object, the metal-coated abrasive of the present invention according to claim 1 has a surface coated with a metal coating layer, The surface of this metal coating layer is chemically etched to form fine irregularities. In the metal-coated abrasive grain having the above-described configuration, the surface of the metal-coated layer is chemically roughened by etching, so that the entire surface of the metal-coated layer is roughened with, for example, hook-shaped protrusions. A fine uneven surface shape can be formed. At the time of bonding between the surface of the metal coating layer and the resin binder phase, the anchor effect is large, the mechanical bonding strength can be improved as compared with the conventional metal coating layer, and a large load is applied to the abrasive grains during heavy grinding. Even when it acts, it is possible to suppress the abrasive grains from falling off. Furthermore, since the surface area of the metal coating layer is large, it has high heat dissipation.

[0005] A resin-bonded grinding wheel according to the present invention is characterized in that the above-mentioned metal-coated abrasive grains are dispersed and fixed in a resin binder phase. In the resin bond whetstone having the above configuration, since the surface of the metal coating layer has a roughened shape with fine irregularities, it is intertwined with each other when bonding with the resin binder phase, and the anchor effect is large, so that the metal coating abrasive grains and the resin The mechanical bonding strength with the binder phase is greater than that of conventional metal-coated abrasive grains, and even when a heavy load acts on the abrasive grains during heavy grinding, the falling-off of the abrasive grains is suppressed well, and the surface area of the metal coating layer is reduced. Because of its large size, it has high heat dissipation and high heat resistance to grinding heat.

According to a third aspect of the present invention, there is provided a method for producing metal-coated abrasive grains, wherein a surface of the abrasive grains is coated with a metal coating layer, and the surface of the metal coating layer is chemically etched to form fine irregularities. It is characterized by forming. In the method of manufacturing the metal-coated abrasive grains, a metal coating layer is formed on the surface of the abrasive grains by electroless plating or the like, and thereafter, the surface of the metal coating layer is chemically etched. It is possible to form a rough and fine uneven surface shape with protruding protrusions having hook-like tips. Here, by applying an etching agent on the surface of the metal coating layer and roughening the surface, a surface shape having a large mechanical bonding strength with the resin binder phase can be obtained, and the production is easy.

[0007]

An embodiment of the present invention will be described below with reference to the accompanying drawings. Note that the same reference numerals are assigned to the same parts as those in the above-described conventional technology, and the description will be simplified or omitted. FIG. 1 is an enlarged sectional view of a superabrasive according to the present embodiment, and FIG. 2 is a partial longitudinal sectional view of a resin-bonded grindstone in which an abrasive layer including the superabrasive shown in FIG. FIGS. 3 (a), 3 (b), 3 (c) and 3 (d) are views showing a production process of metal-coated abrasive grains according to the present embodiment, and FIGS.
Shows the surface of the metal-coated abrasive grains, (a) is a diagram of the present embodiment, (b) is a diagram of a conventional example, FIG. FIG. FIG.
The metal-coated abrasive grain 10 shown in FIG. 1 includes a super-abrasive grain 1 such as diamond or cBN inside, and the outer surface thereof has, for example, 2 to 10 μm.
A metal coating layer 11 having a thickness of about m is formed, and the metal coating layer 11 is formed of, for example, a copper coat layer or a nickel coat layer made of copper, copper oxide, cupric oxide, or the like. On the outer surface of the metal coating layer 11, there are formed a large number of fine projections 11a having a hook-like or anchor-like shape, for example, obtained by chemical etching.

The surface of the metal coating layer 11 is etched with a chemical for etching to form a fine surface having a height of, for example, 0.3 to 3.0 μm and an outer diameter of about 0.1 to 1.0 μm. A large number of protrusions 11a having a hook-like or anchor-like tip are formed, so that the outer surface of the metal coating layer 11 has a rough texture (Glengross) as shown in FIG. ) And a large number of fine irregularities are formed. That is, the tip of the caldera-shaped or column-shaped projection has a hook-like or anchor-like shape to form irregularities. On the other hand, the metal-coated abrasive grains 3 in which only the super-abrasive grains 1 are coated with copper as the metal-coated layer 2 (11) have a relatively smooth surface as shown in FIG. FIG. 2 shows a resin-bonded grindstone 20 according to the present embodiment. The resin-bonded grindstone 20 is provided with an abrasive layer 21 on a base metal 5. The abrasive layer 21 is made of a thermoplastic resin such as phenol. Metal-coated abrasive grains 10 in a resin-bound phase 7 such as resin or polyimide resin.
Are distributed and fixed. This metal-coated abrasive grain 1
0 denotes a large number of fine protrusions 11a on the outer surface of the metal coating layer 11.
Are remaining and roughened, and these projections 1
1a... Are connected in a state of being intertwined with the resin binding phase 7 because the tips are formed in a hook shape, an anchor shape, or the like, for example.
Its mechanical bonding strength is significantly higher than that of the superabrasive 1 having the conventional metal coating layer 2. Therefore, metal-coated abrasive grains 1
0 and the resin bonding phase 7 have a further improved mechanical bonding degree, and have a high abrasive grain holding force that can withstand heavy grinding.
0 increases the heat radiation effect.

Next, the metal-coated abrasive grains 1 according to the present embodiment
0 and a method of manufacturing the resin bond whetstone 20 using the abrasive grains 10 will be described. First, the outer surface of the superabrasive grain 1 shown in FIG. 3A is coated with, for example, copper by electroless plating. In this case, the superabrasive grains 1 and the copper constituting the copper coating layer 11A as the metal coating layer 11 are used in a weight ratio of, for example, 1: 1 and the obtained FIG. 3 (b) is obtained.
The super-abrasive grains indicated by have the same configuration as the metal-coated abrasive grains 3 of the prior art, and are referred to as copper-coated abrasive grains 10A. Next, an etching agent such as, for example, Mech Etch Bond (trademark) is applied to the outer surface of the copper-coated abrasive grains 10A to perform an etching treatment. Thus, as shown in FIG.
As shown in (d), a large number of projections 11a having tips such as hooks or anchors remain on the surface of the copper coating layer 11A, and the projections 11a have an island-like columnar shape as a whole. A metal-coated abrasive grain 10 shown in FIG. 1 having a caldera shape with a hole in the center of the caldera and having the copper coating layer 11A as the metal coating layer 11 is manufactured. Next, the metal-coated abrasive grains 10 are mixed with a raw material powder such as a thermoplastic resin or a thermosetting resin such as a phenol resin or a polyimide resin, and are molded together with the alloy 5 or independently, followed by press molding and firing. Thus, the resin bond whetstone 20 or its abrasive grain layer 21 can be formed.

As described above, according to the present embodiment, the metal-coated abrasive grains 10 with the surface of the metal-coated layer 11 roughened as the abrasive grains of the resin-bonded grinding stone 20 are dispersed and mixed in the resin binder phase 7. As a result, the metal coating layer 11 of the metal coating abrasive grains 10
For example, the resin bonding phase 7 enters the protrusions 11a having hook-shaped or anchor-shaped tips and the like, and is bonded, so that the mechanical bonding strength is high. Therefore, for example, even if a large load acts on the metal-coated abrasive grains 10 during heavy grinding, the metal bond abrasive grains 10 can be prevented from falling off from the resin bonding phase 7 and the life of the resin bond grinding stone 20 can be extended. In addition, the metal-coated abrasive grains 10 are
Has a large surface area due to the protrusions 11a..., And has a high heat dissipation property, so that the grinding heat generated in the metal-coated abrasive grains 10 during grinding can be efficiently released through the resin bonding phase 7, and in this respect also, the life of the resin bond grinding wheel 20 can be improved. Can be improved.

Next, the bending strength of the metal-coated abrasive grains 10 according to the embodiment of the present invention, the resin-bonded grindstone 20 having the metal-coated abrasive grains dispersed therein, and the metal-coated abrasive grain 1 of the conventional example and the resin-bonded grindstone 6 having the metal-coated abrasive grains 1 dispersed therein are arranged. Was compared. In each of the embodiment and the conventional example, the superabrasive grains 1 are made of diamond, the metal coating layers 11 and 12 are made of copper, and the resin bonding phase 7 is made of phenol resin. When the bending strength of the metal-coated abrasive grain 10 according to the embodiment in which the thickness of the metal coating layer 11 is equal to the thickness of the metal-coated layer 2 is compared with that of the metal-coated abrasive grain 3 according to the conventional example, as shown in FIG. It was about 12.1 kgf, about 9.9 kgf in the conventional example, and the bending strength of the present example was improved by about 20%.

In this embodiment, the super-abrasive grains 1 made of diamond, cBN, etc. are used as the abrasive grains. However, the present invention is not limited to this, and general abrasive grains such as SiC and Al ₂ O ₃ may be used. Can be used. The agent for etching the copper coating layer 11A is not limited to Mech-etch bond (trademark), and an oxidizing agent such as potassium persulfate and a pit generator may be used. When the superabrasive 1 is coated with the metal coating layer 11, the metal coating layer 11 does not necessarily have to be coated by electroless plating, and may be formed by other methods, for example, electroplating, PVD, CVD, or the like. In addition, the metal-coated abrasive grains of the present invention can be used for grinding wheels other than the resin-bonded grinding wheel.

[0013]

As described above, according to the metal-coated abrasive grains of the present invention, the surface of the abrasive grains is coated with a metal coating layer, and the surface of the metal coating layer is finely etched by chemical etching. Since the unevenness is formed, the anchor effect is large when bonding with a binder phase made of, for example, resin, and the mechanical bonding strength is larger than that of the conventional metal coating layer. However, the abrasive grains are prevented from falling off, and the metal coating layer has a large surface area, so that it has high heat dissipation and high heat resistance.

The resin-bonded grindstone according to the present invention is formed by dispersing and fixing the above-described metal-coated abrasive grains in a resin binder phase, so that the metal-coated abrasive grains have a roughened surface having fine irregularities. Because of this, the resin enters the unevenness when bonding with the resin binder phase, the anchor effect is large, the mechanical bond strength with the resin binder phase is larger than conventional metal-coated abrasive grains, and a large load is applied to the abrasive grains during heavy grinding Even when the voltage is applied, the abrasive grains are prevented from falling off. In addition, since the surface area of the metal coating layer is large, the metal coating layer has high heat dissipation even with respect to grinding heat, and can improve the life of the grinding wheel.

Further, in the method for producing metal-coated abrasive grains according to the present invention, the surface of the abrasive grains is coated with a metal coating layer, and the metal coating layer is chemically etched to form, for example, a hook or anchor at the tip. Because it forms fine projections in the shape of
By simply applying a chemical for etching treatment to the surface of the metal coating layer, a large number of fine irregularities can be formed on the entire surface of the metal coating layer, and processing is easy.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a metal-coated abrasive grain according to an embodiment of the present invention.

FIG. 2 is a partial longitudinal sectional view of a resin-bonded grindstone provided with the metal-coated abrasive grains shown in FIG.

FIG. 3 is an explanatory view of a main part showing a method for producing metal-coated abrasive grains according to the present embodiment.

4A and 4B show surfaces of metal-coated abrasive grains, wherein FIG. 4A is a diagram of the present embodiment, and FIG. 4B is a diagram showing a conventional example.

FIG. 5 is a view showing the transverse rupture strength of metal-coated abrasive grains according to an example of the present invention and a conventional example.

FIG. 6 is a cross-sectional view of a conventional metal-coated abrasive grain.

7 is a partial cross-sectional view of a resin-bonded grindstone provided with the metal-coated abrasive grains shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Super-abrasive grain 7 Resin bonding phase 10 Metal-coated abrasive grain 11 Metal-coated layer 11a Projection 20 Resin bond whetstone 21 Abrasive grain layer

Claims (3)

[Claims] 1. A metal-coated abrasive in which the surface of the abrasive is coated with a metal coating layer, and the surface of the metal coating is chemically etched to form fine irregularities. 2. A resin-bonded grinding wheel, wherein the metal-coated abrasive grains according to claim 1 are dispersed and fixed in a resin binder phase. 3. A method for producing metal-coated abrasive grains, wherein a surface of the abrasive grains is coated with a metal coating layer, and the surface of the metal coating layer is chemically etched to form fine irregularities. .