JPH0655457A - Lightweight super abrasive grain metal bond wheel and its manufacture - Google Patents

Abstract

PURPOSE:To provide a super abrasive grain metal bond wheel whose super abrasive grain layer is highly adhesive while being very light in weight as well as to provide a means for efficiently manufacturing the super abrasive grain metal bond wheel. CONSTITUTION:The wheel is made up of a base metal 1, and of a super abrasive grain layer 4 adhering on the base metal 1. The base metal is made of aluminum alloys, and let the super abrasive grain layer 4 adhere to the base metal by means of sintering via a metal plating layer whose melting point is higher than the sintering temperature of the super abrasive grain layer 4 formed on the surface of the base metal 1. In order to manufacture the aforesaid wheel, a metal plating layer whose melting point is higher than the sintering temperature of the super abrasive grain layer 4 is formed over the surface of the base metal 1 made of aluminum alloys, the base metal 1 is then put into metallic molds 2 and 3, raw material for the super abrasive grain layer mainly composed of super abrasive grains and metallic powder is filled in the molds in such a way as to be brought into contact with the plating layer, the raw material for the super abrasive grain layer is then pressed with pressure so as to be molded, and a compact thus produced is sintered in the temperature range of 350 deg.C to temperature lower than the melting point of the base metal 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superabrasive metal bond wheel used for various grinding operations such as straight type, cup type, and double-sided grinding wheels. Regarding the wheel.

[0002]

2. Description of the Related Art Conventionally, a superabrasive grain metal bond wheel having a superabrasive grain layer fixed to a base metal has been used for various kinds of grinding of cemented carbide, ceramics, glass, tool steel and the like.

In such a metal bond wheel, an iron base metal having excellent strength is generally used, and a superabrasive grain layer is fixed to the outer periphery and the side surface of the base metal.

However, although such an iron base metal is excellent in strength, it has a heavy weight. Therefore, in a grinding machine having low spindle rigidity, the spindle swings during wheel rotation and stable grinding cannot be performed. There is a problem that the work is difficult. In addition, since the wheel mounting hole and the reference surface are rusted by the grinding fluid and moisture, there is a problem that accurate mounting cannot be performed and highly accurate grinding cannot be performed.

Therefore, as a solution to these drawbacks, a lightweight superabrasive metal bond wheel made of aluminum alloy has been developed in recent years. With such a base metal, the weight of the wheel is about one-third that of steel, and it is possible to significantly reduce the weight, and it is possible to perform stable grinding even with a grinding machine having low spindle rigidity.

As a method for manufacturing a metal bond wheel made of such an aluminum alloy base metal, a superabrasive grain layer is fixed to a conventional iron base metal by a direct attachment method, and the inner peripheral portion of the base metal is hollowed out after sintering. Alternatively, a method of bonding an aluminum alloy base metal using an adhesive or a method of pre-sintering a superabrasive grain layer in a ring shape, and applying an adhesive to the aluminum alloy base metal A method of using and bonding is known.

[0007]

However, in the former method, the outer circumference, which occupies most of the weight of the wheel, is made of iron, and not only the weight is not sufficiently reduced, but also the manufacturing process becomes complicated. In addition, the heat of grinding causes deterioration of the adhesive, which causes a problem in adhesive strength. Further, in the latter method, the ring of the superabrasive grain layer undergoes heat contraction during sintering and is deformed, so it is necessary to process the base metal made of aluminum alloy in accordance with the deformation, which complicates the manufacturing process, and Requires a high level of adhesive technology, and there is a problem in adhesive strength.

[0008] Therefore, the problem to be solved by the present invention is to solve the above-mentioned conventional problems, and a superabrasive grain metal bond wheel having a strong adhesion force of the superabrasive grain layer and excellent in light weight, and the above. It is to obtain a means for efficiently manufacturing a super-abrasive metal bond wheel.

[0009]

In order to solve the above-mentioned problems, the present invention comprises a base metal and a superabrasive grain layer adhered to the base metal, wherein the base metal is made of an aluminum alloy, and The abrasive grain layer is fixed by sintering through a metal plating layer having a melting point higher than the sintering temperature of the superabrasive grain layer formed on the surface of the base metal.

Further, in the method for manufacturing a super-abrasive grain metal bond wheel, a metal plating layer having a melting point higher than the sintering temperature of the super-abrasive grain layer is formed on the surface of an aluminum alloy base metal, and the base metal is placed in a mold. The superabrasive grain layer raw material containing superabrasive grains and metal powder as main components is filled so as to be in contact with the plating layer, and thereafter the superabrasive grain layer raw material is pressure-molded. ℃
To sintering at a temperature range lower than the melting point of the base metal to form a superabrasive grain layer, and at the same time, the superabrasive grain layer is fixed to the base metal.

If the difference in linear expansion coefficient between the aluminum alloy and the superabrasive grain layer is large, it may cause cracking or peeling of the superabrasive grain layer, and the linear expansion coefficient of the aluminum alloy is
From the coefficient of linear expansion of the superabrasive layer equal to or higher than 21 × 10 ^-6 / ° C
The following range is desirable. The coefficient of linear expansion of the superabrasive layer raw material changes depending on the type of metal bond, the content of superabrasive particles (concentration), and the amount of additives (filler), so use an aluminum alloy with a coefficient of linear expansion that matches the coefficient. To do. The linear expansion coefficient of the base metal can be adjusted by using, for example, an aluminum alloy containing a large amount of silicon.

As the metal plating formed on the surface of the base metal,
A material formed by conventional electrolytic plating can be used, and nickel plating or copper plating, which has excellent adhesion to an aluminum wheel, is desirable.

Further, as the metal bond which can be sintered at a temperature lower than the melting point of the aluminum alloy, a bronze-based metal bond having a high tin ratio, whose main components are copper and tin, can be used.

Wheels using the above materials can be manufactured by a conventional hot pressing method. At that time, the pressure is preferably 25 MPa or more in order to obtain adhesion between the metal plating on the surface of the base metal and the raw material for the superabrasive layer.

[0015]

In the super-abrasive grain metal bond wheel of the present invention, the raw material for the super-abrasive grain layer is solidified due to the high temperature during sintering, and the metal plating layer on the surface of the aluminum alloy base metal is the super-abrasive grain layer and the metal. To form a superabrasive grain layer, which is fixed to the aluminum alloy.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 (a) is a diagram showing the working process of the present invention.
First, a metal plating layer is formed on the surface of the aluminum alloy base metal 1 by a conventional method. Next, the lower pressing die 2 and the outer die 3 are arranged below and around the base metal 1. And base metal 1
Then, the space created by the lower pressing die 2 and the outer die 3 is filled with the superabrasive layer raw material. Further, the raw material for the superabrasive layer is pressed from above by the upper pressing die 5, and then sintered by the hot pressing method. As a result, the superabrasive grain layer 4 is fixed to the outer periphery of the base metal 1. After that, the inclined portion 6 is cut according to the width of the superabrasive grain layer 4, and the superabrasive metal bond wheel 7 shown in FIG.
Is completed.

FIG. 2 is a partial plan view of the super-abrasive metal bond wheel 7, where 1 is a base metal, 8 is a plating layer on the outer peripheral portion of the base metal 1, and 4 is a super-abrasive grain layer. Although the so-called straight type wheel has been described in the embodiments of FIGS. 1 and 2, the present invention is not limited to this, and is of course applicable to a cup type, a double-sided grinding wheel and the like. .

[Test Example] As an example product, an aluminum alloy casting AC8 having a linear expansion coefficient of 19 × 10 ⁻⁶ / ° C. on a base metal
Using A, a copper plating layer having a thickness of 30 μm was formed on the surface of the base metal. Further, a bronze-based metal bond of 65% by weight of copper and 35% by weight of tin and a grain size of superabrasive grains #
170 (mesh size) synthetic diamond was filled at a content rate of 25% by volume. This was sintered for 2 hours at a temperature of 500 ° C. and 30 MPa by the above method. After that, cutting is performed, wheel outer diameter 150 mm, superabrasive layer thickness 3 m
m, width of superabrasive layer 5 mm, wheel mounting hole diameter 31.7
A 5 mm superabrasive metal bond wheel was created.

As a comparative example, an abrasive grain layer having the same dimensions and the same composition and sintered in a ring shape in advance was fixed to an aluminum alloy base metal with an adhesive.

Both products were mounted on a rotation tester and the number of rotations was increased until the wheel broke. As a result, the example product was not destroyed even at 21,000 rpm (peripheral speed: 164 m / sec), which is the upper limit of the rotation speed of the machine. On the other hand, in the comparative example, 13,000 rotations (peripheral speed: 102 m /
In seconds), the superabrasive grain layer came off the base metal and broke.

Next, a grinding test was actually conducted using the product of this example and the product of the comparative example. The wheel size and the content of the composition are the same as those of the above test example products. Grinding conditions were a 100 cc grinding test using a surface crushing machine of 2 horsepower and alumina ceramics at a wheel rotation speed of 2000 rpm (peripheral speed: 16 m / sec) and a cut of 0.02 mm / pass.

FIG. 3 shows the chipping (lack of the ground surface of the workpiece), surface roughness (Rmax), grinding ratio (amount of workpiece removed / amount of wheel polished) and average power consumption during grinding. The product of this example showed a clear superiority.

[0023]

According to the present invention, the following effects can be obtained.

(1) Since the weight is reduced, highly accurate grinding can be performed even by a grinding machine having a low spindle rigidity.

(2) Since the metal plating layer and the metal bond are metallically bonded to each other, the aluminum alloy base metal having excellent lightweight properties and the superabrasive grain layer can be reliably bonded, and the bonding strength is high. Excellent in safety.

(3) Since the pressure-sensitive sintering of the abrasive grain layer and the fixing to the base metal can be performed at the same time, the manufacturing process is simplified and the productivity is good.

(4) Since the pressure-sensitive sintering of the abrasive grain layer and the fixing to the base metal can be performed at the same time, the shape of the abrasive grain layer can be formed into an arbitrary shape.

[Brief description of drawings]

FIG. 1A is a sectional view for explaining a manufacturing process of the present invention, and FIG. 1B is a sectional view of a superabrasive metal bond wheel manufactured according to the present invention.

FIG. 2 is a partial plan view of a superabrasive metal bond wheel manufactured according to the present invention.

FIG. 3 is a diagram showing test results.

[Explanation of symbols]

 1 Aluminum alloy base metal 2 Bottom pressing type 3 External type 4 Superabrasive grain layer 5 Top pressing type 6 Deleted part 7 Superabrasive grain metal bond wheel 8 Metal plating layer

Claims (3)

[Claims] 1. A superabrasive grain comprising a base metal and a superabrasive grain layer adhered to the base metal, wherein the base metal is made of an aluminum alloy, and the superabrasive grain layer is formed on the surface of the base metal. A lightweight superabrasive metal bond wheel characterized by being fixed by sintering through a metal plating layer having a melting point higher than the sintering temperature of the layer. 2. The linear expansion coefficient of the aluminum alloy base metal is equal to or higher than the linear expansion coefficient of the superabrasive grain layer and is 21 × 10 ^−6.
The lightweight super-abrasive metal bond wheel according to claim 1, wherein the weight is in the range of / ° C or less. 3. A metal plating layer having a melting point higher than the sintering temperature of the superabrasive grain layer is formed on the surface of the aluminum alloy base metal, and the base metal is incorporated into a mold to be in contact with the plating layer. A raw material for the superabrasive grain layer containing superabrasive grains and metal powders as main components is filled, and then the raw material for the superabrasive grain layer is pressure-molded, and the compact is heated from 350 ° C. to a temperature lower than the melting point of the base metal. A method for manufacturing a lightweight super-abrasive metal bond wheel that is sintered in a temperature range.