JP2003094341A - Metal bond super abrasive whetstone - Google Patents

Abstract

(57) [Problem] To improve the sharpness of a bronze-based metal bond used for grinding difficult-to-cut materials such as ceramics, cemented carbide, and cermet, thereby enabling high-efficiency grinding. SOLUTION: In a bronze metal bond (Cu-Sn composition), S
one or more hard particles selected from i ₃ N ₄ , Al ₂ O ₃ , SiC, WC, and B ₄ C;
One or more kinds of soft particles selected from oS ₂ , Cr ₂ O ₃ , and graphite are dispersed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention has a good sharpness,
The present invention relates to a long-life metal-bond superabrasive grindstone.
In particular, the present invention relates to a metal bond superabrasive grindstone capable of highly efficiently grinding difficult-to-cut materials such as ceramics, cemented carbide, and cermet.

[0002]

2. Description of the Related Art Conventionally, for grinding various materials such as glass, silicon, ferrite, cemented carbide and cermet,
Metal-bonded superabrasive grindstones are used because of their good sharpness and long life. A metal bond superabrasive grindstone generally has a form in which a sintered body of a mixture of diamond or CBN (cubic boron nitride) superabrasive particles and metal bond powder is bonded to the surface of a metal base metal. There is. Among the metal bonds, bronze-based metal bonds, steel-based metal bonds, cobalt-based metal bonds, nickel-based metal bonds, tungsten-based metal bonds, etc. are known, depending on the type of the metal as the main component. Cu-Sn) based metal bonds are most often used.

Particularly in the grinding of difficult-to-cut materials such as ceramics, cemented carbide, and cermet, the above-mentioned bronze-based metal bond reduces the working efficiency due to a decrease in sharpness, so MoS ₂ and Cr ₂ as solid lubricants O ₃ and graphite were added to slightly improve this problem. However, when a more efficient grinding process is required, satisfactory results cannot be obtained with the above solid lubricant alone.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems. That is, the sharpness of a bronze-based metal bond used for grinding difficult-to-cut materials such as ceramics, cemented carbide, and cermet is improved to enable high-efficiency grinding.

[0005]

In order to solve the above problems, the inventors of the present invention have mainly described in detail the composition of the Cu-Sn alloy in the bronze-based metal bond and the relationship between the kind and the amount of the additive. a result of attempting the study, _Si 3 _N 4 in the Cu-Sn alloy is a _matrix, Al _{2 O} 3,
Dispersing one or more kinds of hard particles selected from SiC, WC, and B ₄ C and one or more kinds of soft particles selected from MoS ₂ , Cr ₂ O ₃ , and graphite. According to ceramics, cemented carbide,
It has been found that there is a remarkable effect in improving high-efficiency grinding such as cermet. The specific configuration is as follows.

The metal-bonded superabrasive grain grindstone of the present invention is a metal-bonded superabrasive grain grindstone in which superabrasive grains composed of diamond or CBN are dispersed in a metallic bond phase. , Dispersed in the soft metal layer,
It is characterized by having hard particles and soft particles.

The soft metal layer is composed of Cu and Sn, the Cu content is 45 to 65% by weight, and the remaining amount is S.
It is characterized by being n. Regarding the composition of this soft metal layer, when grinding difficult-to-cut materials such as ceramics, cemented carbide, and cermet, Cu is 47 to 47
More preferably, it is 65% by weight and the balance is Sn. Further, it is more preferable that Cu is 49 to 63% by weight and the remaining amount is Sn.

The hard particles are made of Si._ThreeN_Four, A
l_TwoO_Three, SiC, WC, and B _FourSelected from C
Characterized by being one or more kinds of hard particles
To do. Hard particles are Si_ThreeN_Four, Al
_TwoO_Three, SiC, WC, and B_FourChoose from C or
It may be SiC or Al_TwoO_ThreeIs easy to obtain and priced
It is suitable because it is cheap. Also, the particle size of this hard particle
Is finer than superabrasive grains. For example, die
The grain size of yamond is according to JIS B 4130.
When using 200/230 degrees, the particle size of the hard particles
Uses a finer grain size 230/270 or equivalent
Good. Generally, it is finer than 2 ranks according to JIS standard.
It is more preferable to use a pad size. In addition, this hard grain
If the particle size is too small, the effect cannot be expected
And at least the average particle size is 1 μm or more.
Is preferable, and more preferably 5 μm or more. Well
Also, the proportion of hard particles occupied in the metallic binder phase is
The product ratio is preferably 5 to 45%. 5% not yet
At full, the effect of containing hard particles can hardly be expected,
If it exceeds 45%, the metallic binder phase becomes brittle and fractures.
This is because it becomes easier.

Further, the soft particles are composed of MoS ₂ , Cr.
It is characterized by being one kind or two or more kinds of soft particles selected from ₂ O ₃ , h-BN (hexagonal boron nitride) and graphite. In the case of soft particles, the effect may be expected even if the particles are coarser than the superabrasive particles. Generally, the average particle size of the soft particles is 1 to 1000 μm, and the most commonly used range is 5 to 800 μm. Further, the proportion of the soft particles occupied in the metal binder phase is preferably 5 to 40% in volume ratio. If it is less than 5%, the effect of containing soft particles can hardly be expected,
This is because if it exceeds 40%, the metallic binder phase becomes brittle and easily breaks.

The metal-bonded superabrasive grindstone of the present invention is characterized by being used for grinding ceramics, cemented carbide, cermet and the like.

[0011]

(Example 1) In the metal-bonded superabrasive grindstone of Example 1, diamond is dispersed in the metal bonding phase, and in the metal bonding phase, a soft metal layer (65 wt% Cu-35) is used.
Wt% Sn), and hard particles (SiC) and soft particles (graphite) dispersed in the soft metal layer. This metal bond superabrasive grindstone was manufactured by the following method. First, C so as to be 65 wt% Cu and 35 wt% Sn
The u powder and the Sn powder were weighed and mixed, and this mixture was mixed with a ball mill until uniform. Thereafter, SiC (average particle size of about 15 μm) and graphite (average particle size of about 20 μm) were further added to the mixture and mixed until they became uniform.
The final mixing ratio was Cu: Sn: SiC: graphite = 52% by weight: 28% by weight: 10% by weight: 10% by weight.
Further, this mixture was added with diamond grain size # 800 (average grain size 20 μm) so as to have a concentration of 100, and the mixture was filled in a predetermined die and sintered by hot pressing to obtain the metal of Example 1. A bonded superabrasive stone was manufactured. The grindstone is a straight type (1A1 type) having an outer diameter of 200 mm, a grindstone thickness of 10 mm, and an abrasive grain layer thickness of 3 mm.

(Comparative Example 1) As Comparative Example 1, a metal-bonded superabrasive grindstone containing no hard particles (SiC) was manufactured. That is, the metal bond superabrasive grindstone of Comparative Example 1
Diamond is dispersed in the metal binding phase, and the soft metal layer (58 wt% Cu-42 wt% S is included in the metal binding phase.
n) and soft particles (graphite) dispersed in the soft metal layer. This metal bond superabrasive grindstone was manufactured by the following method. First, 65 wt% Cu, 35 wt%
Cu powder and Sn powder were weighed and mixed so as to become Sn,
This mixture was mixed with a ball mill until uniform.
After that, the mixture is further added with graphite (average particle size of about 20 μm)
Was added and mixed until they were uniform. The final mixing ratio is Cu: Sn: graphite = 58% by weight: 31% by weight:
It was 11% by weight. Next, this mixture was added with diamond # 800 (average particle size 20 μm) so that the degree of concentration was 100, and the mixture was filled in a predetermined die and sintered by a hot pressing method to carry out the metal bond of the example. A superabrasive whetstone was manufactured. The size of the grindstone is the same as in Example 1, and the outer diameter is 200
mm, the thickness of the grindstone is 10 mm, and the thickness of the abrasive layer is 3 mm, which is a straight type (1A1 type).

A grinding test was conducted to confirm the effect of the present invention. Each of the above metal-bonded superabrasive grindstones was attached to a horizontal axis surface grinder, and a TiN-based cermet was ground for comparison. The grinding condition is a grinding wheel peripheral speed of 160.
0 m / min, workpiece speed 50 mm / min, cutting depth 0.
8 mm / pass, grinding fluid JIS W2 (2% aqueous solution). The result is shown in FIG. Example 1 had a low grinding resistance and exhibited stable sharpness. On the contrary, Comparative Example 1
Had the same grinding resistance as in Example 1 at the start of the grinding process, but the grinding resistance gradually increased, and it became impossible to continue the grinding test.

(Example 2) In the metal-bonded superabrasive grindstone of Example 2, diamond is dispersed in the metal bonding phase, and the soft metal layer (58 wt% Cu-42% by weight) is contained in the metal bonding phase.
Wt% Sn), and hard particles (SiC) and soft particles (graphite) dispersed in the soft metal layer. This metal bond superabrasive grindstone was manufactured by the following method. First, C is added so as to be 58 wt% Cu and 42 wt% Sn.
The u powder and the Sn powder were weighed and mixed, and this mixture was mixed with a ball mill until uniform. Thereafter, SiC (average particle size of about 15 μm) and graphite (average particle size of about 20 μm) were further added to the mixture and mixed until they became uniform.
The final mixing ratio was Cu: Sn: SiC: graphite = 46% by weight: 34% by weight: 12% by weight: 8% by weight. Next, diamond # 600 (average particle size 30
The metal-bonded superabrasive grindstone of the example was manufactured by filling a predetermined metal mold with a mixture having a concentration of 125 μm) and sintering it by a hot pressing method. The grindstone is a straight type (1FF1 type) with an outer diameter of 125 mm, a grindstone thickness of 2 mm, and a roundness R1 mm of the abrasive grain layer with R.

(Comparative Example 2) As Comparative Example 2, a metal bond superabrasive grindstone containing no hard particles (SiC) was manufactured. That is, the metal bond superabrasive grindstone of Comparative Example 2 is
Diamond is dispersed in the metal binding phase, and the soft metal layer (58 wt% Cu-42 wt% S is included in the metal binding phase.
n) and soft particles (graphite) dispersed in the soft metal layer. This metal bond superabrasive grindstone was manufactured by the following method. First, 58 wt% Cu, 42 wt%
Cu powder and Sn powder were weighed and mixed so as to become Sn,
This mixture was mixed with a ball mill until uniform.
After that, the mixture is further added with graphite (average particle size of about 20 μm)
Was added and mixed until they were uniform. The final mixing ratio is Cu: Sn: graphite = 53% by weight: 38% by weight:
It was 9% by weight. Then add diamond # 6 to this mix.
00 (average particle size: 30 μm) was added to the glass in such a manner that the degree of concentration was 125, and the mixture was filled in a predetermined mold and sintered by a hot press method to manufacture the metal bond superabrasive grindstone of the example. The size of the grindstone is the same as in Example 2.

Next, the following grinding test was carried out to confirm the effect of the present invention. The metal bond superabrasive grindstones of Example 2 and Comparative Example 2 were attached to a universal tool grinder, and TiN was used.
Grinding of the system cermet chip was performed. The grinding conditions are grinding wheel peripheral speed 1400 m / min, workpiece speed 50 mm /
Min, depth of cut 0.8 mm / pass, grinding fluid JIS / W
2 (2% aqueous solution). As a result, in Example 2, twice the dress interval as in Conventional Example 2 was obtained.

In the bronze-based metal bond (Cu-Sn composition), S is added to the Cu-Sn alloy that is the matrix.
i ₃ N ₄ , Al ₂ O ₃ , one or more kinds of hard particles selected from SiC, WC, and B ₄ C, and M
By dispersing one or more kinds of soft particles selected from oS ₂ , Cr ₂ O ₃ and graphite, it becomes possible to perform high-efficiency grinding of ceramics, cemented carbide, cermet and the like.

[Brief description of drawings]

FIG. 1 is a schematic view of a superabrasive layer.

FIG. 2 is a graph showing the grinding test results of Example 1 and Comparative Example 1.

[Explanation of symbols]

M Soft metal layer D super abrasive grain h Hard particles s Soft particles

Claims (5)

[Claims] 1. A metal bond superabrasive grain grindstone in which superabrasive grains of diamond or CBN are dispersed in a metal bond phase, wherein the metal bond phase is dispersed in a soft metal layer and the soft metal layer. A metal-bonded superabrasive grindstone characterized by having hard particles and soft particles. 2. The metal-bonded superabrasive grindstone according to claim 1, wherein the soft metal layer is composed of Cu and Sn, the Cu content is 45 to 65% by weight, and the balance is Sn. . 3. The hard particles are made of Si ₃ N ₄ and Al.
1 selected from ₂ O ₃ , SiC, WC, and B ₄ C
The metal-bonded superabrasive grindstone according to claim 1 or 2, characterized in that the particles are hard particles of two or more kinds. 4. The soft particles are MoS ₂ , Cr ₂ O ₃ ,
The metal-bonded superabrasive grindstone according to any one of claims 1 to 3, which is one kind or two or more kinds of soft particles selected from h-BN and graphite. 5. The metal-bonded superabrasive grindstone according to any one of claims 1 to 4, which is used for grinding ceramics, cemented carbide, cermet and the like.