JP3413372B2 - Diamond blade for cutting hard material and cutting device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a diamond blade suitably used for cutting a hard material such as a glass material, a ceramic material, a semiconductor single crystal material or a crystal material, and a cutting of the hard material using the diamond blade. Regarding the device.

[0002]

2. Related Art A conventional diamond blade and a cutting device using the diamond blade will be described with reference to FIGS. FIG. 5 shows an example of a conventional diamond blade. (A) is a front view of the conventional diamond blade, (b) is a sectional view taken along line BB of (a),
FIG. 7C is a schematic explanatory view of a diamond tip portion.

FIG. 6 is a partial cross-sectional explanatory view of a cutting device equipped with a conventional diamond blade. FIG. 6A shows a state before cutting the cutting object, and FIG. 6B shows cutting the cutting object. It is drawing which shows the state in the middle of being.

FIG. 7 is a partial cross-sectional explanatory view showing a state in which an object to be cut is being cut by a conventional diamond blade.
(A) shows the stress received by the cut object, and (b) is a drawing showing a state where the cut object contacts both side surfaces of the metal substrate of the diamond blade.

FIG. 8 is an enlarged partial sectional explanatory view showing a state during cutting of an object to be cut by a conventional diamond blade.
(A) shows a state in which the cutting resistance is large, (b) shows a state in which the diamond blade is warped to cause a warp on the cut surface, (c) shows a state at the end of cutting the cut object, FIG. 3D is a diagram showing a state in which burrs are generated on the cut surface of the object to be cut after cutting.

The conventional diamond blade 10 is shown in FIG.
As shown in FIG.
It is composed of a tip portion 14 having diamond abrasive grains fixed to its outer peripheral portion by metal bond, resin bond, electrodeposition or the like. Reference numeral 16 is a shaft hole formed in the center of the metal substrate 12. Reference numeral 18 denotes a cutting device, which has a rotary drive unit 20 incorporating a drive means such as a motor and a rotary shaft 22 connected to the rotary drive unit 20 [FIG. 6 (a)].
(B)].

When a conventional diamond blade 10 is used to cut a plate G made of a hard material such as a glass material, a ceramic material, a semiconductor single crystal material or a crystal material, a rod, a tube or the like, a diamond blade 1
The shape of the chip portion 14 of 0 is concave with respect to the metal substrate 12, that is, the shape of the tip surface is a flat surface [FIG.
(C)] Therefore, as the cutting of the object G by the diamond blade 10 progresses, a cutting resistance is generated between the object G and the diamond blade 10 [FIG. 7].
(A)].

Since the cutting resistance has two functions of bending the object G to be bent and bending the metal substrate 12 of the diamond blade 10 at the same time, the object G to be cut is a side surface of the metal substrate 12 of the diamond blade 10. 12a
, And chipping (a phenomenon in which a cut surface of the object to be cut G has cracks or chips) was generated [FIG. 7 (b)].

Further, due to the warp of the metal substrate 12 of the diamond blade 10 occurring during cutting [FIG. 8 (b)], the cutting surface M is warped, and the diamond blade 10 escapes at the end of cutting. Happened [Fig. 8
(C)], burr N remains at the end of cutting [FIG. 8]
(D)] was a problem.

[0010]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made extensive studies in order to solve the above problems,
First of all, in order to reduce the cutting resistance during cutting, the cutting resistance is reduced by making the shape of the tip surface of the diamond tip part a projection shape instead of a flat surface, especially the tip surface of the diamond tip part. It has been found that the cutting resistance is favorably reduced by setting the tip angle of the protrusion shape to preferably 45 ° to 120 °.

Secondly, the present inventors have found that when the diamond abrasive grain layer is provided on the side surface of the metal substrate of the diamond blade, the cutting resistance is received during the cutting to bend the object to be cut and contact the diamond blade. In addition to the chipping prevention that occurs in the above, the cutting surface is warped due to the warping of the diamond blade, the escape phenomenon of the diamond blade that occurs at the end of cutting is prevented, and the occurrence of burrs can be prevented. Was completed.

According to the present invention, the cutting resistance during cutting can be satisfactorily reduced, chipping that occurs when an object to be cut bends and contacts the blade due to cutting resistance during cutting, and at the end of cutting An object of the present invention is to provide a diamond blade for cutting a hard material and a cutting device capable of preventing a blade escape phenomenon that occurs and preventing burr from being generated.

[0013]

In order to solve the above-mentioned problems, a diamond blade for cutting a hard material according to the present invention,
A glass material, a ceramic material, a semiconductor single crystal material, or a crystal material having a disk-shaped metal substrate and a diamond tip portion provided on the outer peripheral portion of the metal substrate and having diamond abrasive grains fixed by a metal bond or a resin bond. in hard material cutting diamond blade for cutting certain hard materials, 該Chi abrasive layer formed by fixing abrasive grains on the inner side a and the tip portion of the metal substrate
While being provided continuously over the entire circumference of the cup portion, the shape of the tip surface of the diamond tip portion is formed into a protrusion shape,
The tip angle of the projection shape of the tip surface of the diamond tip portion is set to 45 ° to 120 ° so that the side surface height of the abrasive grain layer is smaller than the side surface height of the diamond tip portion. It is characterized in that the abrasive grains constituting the abrasive grain layer are finer than the diamond abrasive grains constituting the diamond tip portion.

The tip angle of the projection of the tip surface of the diamond tip portion is more preferably 60 ° to 90 °.
Is set to.

When the tip angle of the projection of the diamond tip portion is less than 45 °, the cutting resistance is reduced, but the friction of the diamond tip portion is increased, the life of the diamond blade is shortened accordingly, and the tip angle is also increased. Is more than 120 °, the effect of reducing the cutting resistance is reduced to that extent, but the effect of the present invention is still achieved in these angle ranges.

The side surface height of the abrasive grain layer is smaller than the side surface height of the diamond tip portion, that is, the thickness of the abrasive grain layer is slightly smaller than the thickness of the diamond tip portion, for example, 0.05 mm. It is preferable to have a thickness that is thin to the extent.

It is preferable that the abrasive grains forming the abrasive grain layer are diamond abrasive grains forming the diamond tip portion, for example, # 170, and finer abrasive grains, for example, # 200.

The abrasive grain layer may be provided on the entire side surface of the metal substrate, or may be provided partially. When partially provided, the installation mode is not particularly limited, and for example, a spiral, spiral, radial, multiple concentric, multiple point-like installation mode can be appropriately adopted. .

The abrasive grains constituting the abrasive grain layer are diamond
It is preferably composed of abrasive grains and / or other abrasive grains. So
Other abrasive grains include SiC, Al₂O₃, ZrO₂，
Si ₃N_Four, CBN or BN.
These abrasive grains can be used alone or in combination.
It is also possible.

Examples of hard materials to be cut by the diamond blade include glass materials, ceramic materials, semiconductor single crystal materials, and crystal materials. Examples of the glass material include quartz glass material, soda-lime glass material, borosilicate glass material, lead glass material and the like.

If a hard material cutting device is constituted by the above-mentioned diamond blade and a rotary drive unit for rotating the diamond blade at a high speed, a hard material such as a glass material, a ceramic material, a semiconductor single crystal material, or a quartz material can be used. You can cut things with reduced cutting resistance,
It is possible to prevent chipping and prevent burrs from occurring.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. 1 to 4 in the accompanying drawings. FIG. 1 shows one embodiment of the diamond blade of the present invention. (A) is a front view of the diamond blade of the present invention, (b) is a sectional view taken along line AA of (a), (c). FIG. 4 is a schematic side view showing a diamond tip portion.

2A and 2B are partial cross-sectional explanatory views of a cutting device equipped with a diamond blade of the present invention. FIG. 2A shows a state before cutting the cutting object, and FIG. 2B shows cutting the cutting object. It is drawing which shows the state in the middle of doing.

FIG. 3 is a partial cross-sectional explanatory view showing a state during cutting of an object to be cut by the diamond blade of the present invention,
(A) shows the stress received by the object to be cut, and (b) is a drawing showing a state in which the object to be cut comes into contact with both sides of the metal substrate of the diamond blade and is ground by the diamond abrasive grain layer.

FIG. 4 is an enlarged partial cross-sectional explanatory view showing a state in which an object to be cut is being cut by the diamond blade of the present invention. FIG. 4A shows a state in which the cutting resistance is small, and FIG. Is a diagram showing a state in which the cutting surface does not warp and the escape phenomenon of the diamond blade does not occur, and (c) is a drawing showing a state in which burrs do not occur on the cut surface of the cut object after the cutting is completed. .

1 to 4, members which are the same as or similar to those in FIGS. 5 to 8 may be described using the same reference numerals.

In FIG. 1, a diamond blade 11 for cutting a hard material according to the present invention has a disk-shaped metal substrate 12 rotating at a high speed and a diamond abrasive grain on its outer peripheral portion by metal bonding or resin bonding, as in the conventional case. It is composed of a fixed chip portion 15. Reference numeral 16 is a shaft hole formed in the center of the metal substrate 12. Reference numeral 18 denotes a hard material cutting device, which is the same as the conventional rotary drive unit 20 and rotary shaft 2.
2 and 2 [FIGS. 2 (a) and 2 (b)].

The first characteristic of the diamond blade 11 of the present invention is that, as the cross-sectional shape of the diamond tip portion 15, as shown in FIG. 1 (c), the shape of the projection is such that the tip surface has a tip angle θ. It was done. With such a shape, the cutting resistance is reduced as shown in FIG. 4A as compared with the conventional flat tip shape.

It is preferable that the tip angle θ of the projection shape of the tip surface of the diamond tip portion 15 is set in the range of 45 ° to 120 °. If the tip angle θ is less than 45 °, the cutting resistance decreases, but the diamond tip portion 15
Friction increases, the life of the diamond blade 11 shortens as much, and when the tip angle θ of the diamond tip portion exceeds 120 °, the effect of reducing the cutting resistance becomes smaller, but the action and effect of the present invention are reduced. There is no change in the achievement.

A more preferable range of the tip angle θ is 60 °.
~ 90 °. In the illustrated example, the case of θ = 90 ° is shown as a preferable example.

The second characteristic of the diamond blade 11 of the present invention is that the diamond abrasive grain layer 13 is provided on the side surface 12a of the metal substrate 12 of the diamond blade 11 as shown in FIGS. 1 (a) and 1 (b). is there.

By providing the diamond abrasive grain layer 13 in this manner, the cutting resistance is exerted during cutting and the object to be cut G is cut.
Is bent and comes into contact with the diamond blade 11,
It is possible to prevent chipping, which cannot be avoided by the conventional diamond blade 10.

Furthermore, since both side surfaces 12a of the metal substrate 12 of the diamond blade 11 are coated with diamond abrasive grains to form the diamond abrasive grain layer 13, the diamond blade 11 is coated with the diamond abrasive grain layer 13, The strength is increased and the diamond blade 11 does not warp during cutting. Therefore, the cutting surface does not warp, the escape phenomenon of the diamond blade 11 at the end of cutting does not occur, and the occurrence of burr is complete. Are prevented by [Fig. 4 (a) (b)]
(C)].

The diamond abrasive grains used in the diamond blade 11 of the present invention are the diamond tip portion 1
For No. 5, about 170 may be set as in the conventional case.
On the other hand, the diamond abrasive grains of the diamond abrasive grain layer 13 are
Finer abrasive grains than the diamond abrasive grains of the diamond tip portion 15, for example, about # 200 are preferable.

The side height of the diamond abrasive grain layer 13 is preferably smaller than the side height of the diamond tip portion 15. If the side surface height of the diamond abrasive grain layer 13 is larger than the side surface height of the diamond tip portion, there is a disadvantage that the cutting operation itself becomes difficult.

The diamond abrasive grain layer 13 may be provided on the entire side surface 12a of the metal substrate 12, or may be provided partially. When partially provided, the installation mode is not particularly limited, and for example, a spiral, spiral, radial, multiple concentric, multiple point-like installation mode can be appropriately adopted. .

Examples of hard materials to be cut by the diamond blade 11 of the present invention include glass materials, ceramic materials, semiconductor single crystal materials, and quartz materials. Examples of the glass material include quartz glass material, soda-lime glass material, borosilicate glass material, lead glass material and the like.

As a concrete ceramic material, Si is used.
C rods, alumina rods and the like can be cited, and as semiconductor single crystal materials, there are silicon single crystal, gallium arsenide single crystal and the like.

[0039]

EXAMPLES Examples of the present invention will be described below.

(Example 1) Outer diameter 300 mm, thickness 1.0 mm
On the metal substrate of
mm, width of diamond tip part is 7 mm, diamond abrasive grain of count # 170 is sintered with metal bond and the tip angle of diamond tip part is 90 °. A quartz glass rod having an outer diameter of 80 mm was cut using a blade having a thickness of 0.1 mm and an electrodeposition layer of diamond abrasive grains of # 200.

Detection of cutting resistance: A motor is used to rotate the diamond blade. When cutting resistance is applied to the blade, a load is also applied to the rotating motor, so that the current value flowing through the motor increases. By measuring this current value, the magnitude of the cutting resistance can be detected.

In order to detect the cutting resistance, the current value of the motor for rotating the diamond blade is set to a cutting depth of 5 mm, 1
0mm, 15mm, 20mm, 30mm, 40mm, 60mm, 80
Measurement was made in mm, and the results are shown in Table 1. Further, the numerical values in Table 1 are shown as a graph in FIG. As is clear from Table 1 and FIG. 9, as the cutting progressed, the current value increased and showed the maximum current value at the center of the quartz glass rod, but the current value did not increase so much and the cutting resistance was It was shown to be small.

After the completion of the cutting, the cut surface of the quartz glass rod was observed. As a result, no chipping or burr was generated and no warp was observed.

(Comparative Example 1) Outer diameter 300 mm, thickness 1.0 mm
On the metal substrate of
A quartz glass rod having an outer diameter of 80 mm was cut using a diamond blade having a diamond tip portion of a conventional shape in which a diamond tip portion having a diameter of 7 mm, a diamond tip portion width of 7 mm, and # 170 diamond abrasive grains were sintered by metal bonding.

In order to detect the cutting resistance, the current value of the motor for rotating the diamond blade was measured,
The results are shown in Table 1 and FIG. As the cutting progressed, the current value increased, showing the maximum current value at the center of the quartz glass rod.

When the cut surface of the quartz glass rod after cutting was observed, chips were found on the cut surface. In addition, burrs remained at the end of cutting, and the cut surface was warped by 1 mm. Further, when the side surface of the diamond blade was observed, it was found that scratches were generated in the portion in contact with the quartz glass rod.

(Example 2) Outer diameter 300 mm, thickness 1.0 mm
On the metal substrate of
mm, the width of the diamond tip part is 7 mm, and the diamond abrasive grain of # 170 is sintered with metal bond, and the tip angle of the diamond tip part is 125 °.
A quartz glass rod having an outer diameter of 80 mm was cut using a blade having a thickness of 0.1 mm and an electrodeposited layer of # 200 diamond abrasive grains on both sides from the diamond tip to 80 mm inward.

The current values for detecting the cutting resistance are shown in Table 1.
And as shown in FIG. The maximum current value is shown in Example 1.
However, when the cut surface of the quartz glass rod was observed after completion of the cutting, chipping and burrs were not generated, but it was warped by 0.3 mm.

(Example 3) Outer diameter 300 mm, thickness 1.0 mm
On the metal substrate of
mm, width of diamond tip part is 7mm, diamond abrasive grain of count # 170 is sintered by metal bond and the tip angle of diamond tip part is 40 °. A quartz glass rod having an outer diameter of 80 mm was cut using a blade having a thickness of 0.1 mm and an electrodeposition layer of diamond abrasive grains of # 200.

The current values for detecting the cutting resistance are shown in Table 1.
And as shown in FIG. The maximum current value is shown in Example 1.
Was the same as After the completion of the cutting, the cut surface of the quartz glass rod was observed, but no chipping or burrs were generated, and there was no warpage. However, the tip of the diamond tip was heavily worn, and the tip was reduced by 1 mm.

[0051]

[Table 1]

(Example 4) Outer diameter 300 mm, thickness 1.0 mm
On the metal substrate of
mm, width of diamond tip part is 7 mm, diamond abrasive grain of count # 170 is sintered with metal bond and the tip angle of diamond tip part is 90 °. A rod of SiC having an outer diameter of 60 mm was cut using a blade having a thickness of 0.1 mm and an electrodeposited layer of diamond abrasive grains of # 200.

In order to detect the cutting resistance, the current value of the motor for rotating the blade was measured, and Table 2 and FIG.
The result is as shown in 0. As the cutting progressed, the current value increased, and the maximum current value was shown at the center of the SiC rod, but the increase in current value was not so large that the cutting resistance was small. After the completion of cutting, the cut surface was observed, but there was no occurrence of chips or burrs and there was no warpage.

(Example 5) Outer diameter 300 mm, thickness 1.0 mm
On the metal substrate of
mm, width of diamond tip part is 7 mm, diamond abrasive grain of count # 170 is sintered with metal bond and the tip angle of diamond tip part is 90 °. An alumina rod having an outer diameter of 60 mm was cut using a blade having a thickness of 0.1 mm and an electrodeposition layer of diamond abrasive grains of # 200 count.

In order to detect the cutting resistance, the current value of the motor for rotating the blade was measured, and Table 2 and FIG.
The result is as shown in 0. As the cutting progressed, the current value increased and showed the maximum current value at the central part of the alumina rod, but the increase in current value was not so large that the cutting resistance was small. After the completion of cutting, the cut surface was observed, but there was no occurrence of chips or burrs and there was no warpage.

(Example 6) Outer diameter 300 mm, thickness 1.0 mm
On the metal substrate of
mm, width of diamond tip part is 7 mm, diamond abrasive grain of count # 170 is sintered with metal bond and the tip angle of diamond tip part is 90 °. A gallium arsenide single crystal having an outer diameter of 50 mm was cut using a blade having a thickness of 0.1 mm and an electrodeposition layer of diamond abrasive grains of # 200.

In order to detect the cutting resistance, the current value of the motor for rotating the blade was measured, and Table 2 and FIG.
The result is as shown in 0. As the cutting progressed, the current value increased and showed the maximum current value in the central part of the gallium arsenide single crystal, but the increase in current value was not large,
It showed that the cutting resistance was small. After the completion of cutting, the cut surface was observed, but there was no occurrence of chips or burrs and there was no warpage.

[0058]

[Table 2]

(Examples 7 to 9) A cutting process was performed in the same manner as in Example 1 except that a soda-lime glass rod, a lead glass rod, and a quartz rod were used instead of the quartz glass rod. Results similar to 1 were obtained.

[0060]

As described above, according to the present invention, it is possible to satisfactorily reduce the cutting resistance during cutting, and when the object to be cut bends due to the cutting resistance during cutting and comes into contact with the diamond blade. It is possible to prevent the chipping that occurs in the above, prevent the escape phenomenon of the diamond blade that occurs at the end of cutting, and prevent the occurrence of burrs.

[Brief description of drawings]

1 shows an embodiment of a diamond blade of the present invention, (a) is a front view of the diamond blade of the present invention, (b) is a sectional view taken along line AA of (a) and (c). ) Is a schematic side view of a diamond tip portion.

FIG. 2 is a partial cross-sectional explanatory view of a cutting device equipped with a diamond blade of the present invention, where (a) shows a state before cutting an object to be cut, and (b) shows cutting the object to be cut. It is drawing which shows the state in the middle.

FIG. 3 is a partial cross-sectional explanatory view showing a state during cutting of an object to be cut by the diamond blade of the present invention, (a) shows stress received by the object to be cut, and (b) shows a metal substrate of the diamond blade. It is drawing which shows the state which a to-be-cut object contacts both side surfaces and is ground by a diamond abrasive grain layer.

FIG. 4 is an enlarged partial cross-sectional explanatory view showing a state in which an object to be cut is being cut by the diamond blade of the present invention, (a) shows a state in which cutting resistance is small, and (b) shows that the diamond blade warps. Without showing the warp on the cut surface without showing the escape phenomenon of the diamond blade,
(C) is a drawing showing a state in which burrs do not occur on the cut surface of the object to be cut after the cutting.

FIG. 5 shows an example of a conventional diamond blade, (a) is a front view of the conventional diamond blade,
(B) is the BB sectional view taken on the line of (a), and (c) is the explanatory explanatory view of the diamond tip part.

FIG. 6 is a partial cross-sectional explanatory view of a cutting device equipped with a conventional diamond blade, in which (a) shows a state before cutting an object to be cut, and (b) shows a state of cutting the object to be cut. It is drawing which shows the state inside.

FIG. 7 is a partial cross-sectional explanatory view showing a state during cutting of an object to be cut by a conventional diamond blade, (a) shows stress received by the object to be cut, and (b) shows both sides of a metal substrate of the diamond blade. It is drawing which shows the state in which a to-be-cut object contacts a surface.

FIG. 8 is an enlarged partial cross-sectional explanatory view showing a state in which an object to be cut is being cut by a conventional diamond blade, (a) shows a large cutting resistance, and (b) shows that the diamond blade is warped. The state where the cut surface warps is shown, (c) shows the state at the end of cutting of the cut object,
(D) is a drawing showing a state in which burrs are generated on the cut surface of the object to be cut after cutting.

9 is a graph showing changes in the current value of the diamond blade rotating motor during cutting in Examples 1 to 3 and Comparative Example 1. FIG.

FIG. 10 is a graph showing changes in current value of a diamond blade rotation motor during cutting in Examples 4 to 6.

[Explanation of symbols]

10: Conventional diamond blade, 11: Diamond blade of the present invention, 12: Metal substrate, 12a: Side surface of metal substrate, 13: Diamond abrasive grain layer, 14: Conventional diamond tip portion, 15: Diamond tip portion of the present invention , 16: shaft hole, 18: cutting device, 20: rotary drive unit, 22: rotary shaft, G: object to be cut.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI B24D 5/12 B24D 5/12 Z 5/14 5/14 H01L 21/304 611 H01L 21/304 611S (72) Inventor Toru Mizuno Fukushima Prefecture Iwase-gun Kagamiishi-cho Okagami Fukushima Factory 173 Atok Co., Ltd. Inside the Fukushima Factory (72) Inventor Akihiko Sugama 88, Kawakubo, Kanaya Tamura-cho, Koriyama City, Fukushima Prefecture Shinetsu Quartz Co., Ltd. 1357-3 Fujidan, Kiyoike, Tendo, Shizuoka Prefecture Shintetsu Yamagata Quartz Co., Ltd. (72) Inventor Yoshiaki Ise 1357, Fujidan, Kiyoike, Tendo, Yamagata Yamagata Shinetsu Quartz Co., Ltd. (56) References Special Kaihei 4-82670 (JP, A) JP 8-216031 (JP, A) JP 6-134751 (JP, A) JP 8-309702 (JP, A) JP 7-276244 ( JP A) JP-A-62-68282 (JP, A) JP-B-33-9098 (JP, B1) JP-B-35-1749 (JP, B1) Jikkyo 8-7-1807 (JP, Y2) (58) Survey Areas (Int.Cl. ⁷ , DB name) B24D 5/00-5/12

Claims (5)

(57) [Claims] 1. A glass material, a ceramic material, or a semiconductor single crystal having a disk-shaped metal substrate and a diamond tip portion provided on the outer peripheral portion of the metal substrate and having diamond abrasive grains fixed thereto by metal bond or resin bond. In a hard material cutting diamond blade for cutting a hard material that is a material or a quartz material, an abrasive grain layer formed by fixing abrasive grains to the side surface of the metal substrate and inside the tip portion is continuous to the tip portion. Is provided over the entire circumference , and the tip surface shape of the diamond tip portion is made to be a projection shape, and the tip angle of the projection shape of the tip surface of the diamond tip portion is set to 45 ° to 120 °. The side surface height of the abrasive grain layer is smaller than the side surface height of the diamond tip portion, and the abrasive grains forming the abrasive grain layer are A diamond blade for cutting a hard material, characterized in that the abrasive grains are finer than the diamond abrasive grains constituting the end tip portion. 2. The diamond blade for cutting a hard material according to claim 1, wherein the abrasive grain layer is partially provided on a side surface of the metal substrate. 3. The diamond blade for cutting a hard material according to claim 1, wherein the abrasive grains constituting the abrasive grain layer are diamond abrasive grains and / or other abrasive grains. 4. The other abrasive grains are SiC, Al ₂ O.
_The diamond blade for cutting a hard material according to claim 3, which is ₃ , ZrO ₂ , Si ₃ N ₄ , CBN or BN. 5. A hard material cutting device, comprising: the diamond blade according to any one of claims 1 to 4; and a rotary drive unit for rotating the diamond blade at a high speed.