JPH0525617B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a composite rod-shaped body having a hard head;
The present invention relates to a method for manufacturing a cylindrical body, preferably having a small diameter.

More specifically, the present invention includes a hard head such as a diamond sintered body or a high-pressure phase boron nitride sintered body;
The present invention relates to a method of manufacturing a rod-shaped composite material rod having a small cross section and having a supporting portion made of cemented carbide, for example, which is integrally formed with the head.

The composite material rod-shaped body or cylindrical body obtained by the manufacturing method of the present invention can be used as a material for a high-performance small-diameter drill or as a head portion of a dot printer.

Prior Art Drills made of cemented carbide are often used for drilling holes in metal and non-metal materials. Especially for drilling holes in printed circuit boards, the demand for which has been growing rapidly in recent years, the diameter is 1 mm.
The front and rear cemented carbide drills are used.

Various materials are used for printed circuit boards, but the main one used is a reinforced resin made by impregnating glass fiber with epoxy resin, which is generally called a colored epoxy board.

Drilling of such printed circuit boards is normally done using a highly rigid drill at a rotation speed of 50,000 to 60,000 rpm, but the glass fibers contained in the board wear out the carbide tool very quickly, A carbide drill reaches the end of its lifespan after 3000 to 5000 hits (hits refers to the number of holes drilled). These drill machines are equipped with an automatic tool changer, and the drill that has reached the end of its service life is automatically replaced.However, in order to improve production efficiency, the time required for automatic tool change is also an issue, and the drill life is reduced. There is a strong demand to reduce the number of tool changes, that is, the tool change time.

Looking at the characteristics of printed circuit boards, there is a strong demand for higher functionality by improving heat resistance, etc., and although it is actually possible to manufacture such board materials, it is generally difficult to produce such high-performance materials. Due to cutting, the life of conventional cemented carbide drills is extremely short, and the reality is that this substrate material cannot be put to practical use.

Furthermore, it is desired to increase the rotational speed of the drilling drill in order to drill holes in ordinary glass epoxy substrates with higher efficiency, but this also means that the lifespan of conventional cemented carbide drills rapidly decreases as the cutting speed increases. Since this decreases, high efficiency cannot be achieved from this point of view.

On the other hand, sintered diamond tools, whose usage has been rapidly increasing in recent years, are significantly harder and more wear resistant than carbide tools, and are extremely useful when cutting the reinforced resins mentioned above. Demonstrates high performance.

However, as shown in FIG. 1, this sintered diamond tool consists of a composite sintered body 13 in which a sintered diamond layer 11 is bonded to a support portion 12 of cemented carbide. When manufacturing a drill using this composite sintered body 13, as shown in FIG.
The composite sintered body 13 must be fixed to the tip of the sintered body 5 by some method.

However, the diameter of the tip of this drill is about 1 mm, and if a drill with such a small diameter does not have a very strong joint strength with the shank 15, it will come off from the joint 16 during the grinding process after joining, and it will not work properly. Drills cannot be manufactured. In particular, sintered diamond is difficult to grind, has high grinding resistance, and is insufficient in strength to the level of normal silver brazing. For example, electron beam welding can be considered as a bonding method with high bonding strength, but if electron beam welding were to be implemented, the drill manufacturing process would be complicated and the cost would be high, making it difficult to meet the rapid increase in demand for high-performance drills in recent years. Nakatsuta.

In order to strengthen the connection with the shank 15 and improve the cutting performance of the drill itself, it is ideal if the entire tip of the drill is made of cemented carbide and the head is made of a hard sintered body such as diamond. It is. For this purpose, an elongated composite rod made of cemented carbide with a hard head is required. However, with the conventional techniques, it has not been possible to manufacture a composite sintered body with such a small cross section and a large axial length.

In other words, when manufacturing a product with a large axial length relative to its cross-sectional area, even if the powder material is pressed in the axial direction and hot pressed, the pressure loss due to the powder material layer is large, and the pressure required at the axial center is large. This is because a strong sintered body cannot be obtained.
If this is further pressurized in the axial direction and a high-pressure hot press is performed, the pressure distribution inside the hot press container becomes extremely irregular, making it easy for deformations such as buckling and bending to occur. I can't get a body.

Therefore, in hot pressing of a long and narrow sintered material, the sintered material is laid down so that the axial direction of the sintered material is perpendicular to the pressing direction. Even when a long and narrow composite material is hot-pressed using this method, the pressure in the direction perpendicular to the interface between different material layers is small, and a bond of sufficient strength between the material layers cannot be obtained.

OBJECT OF THE INVENTION The present invention aims to solve the above-mentioned problems of the prior art.More specifically, the present invention has a head made of a hard sintered body, and the head and the support part are integrally formed by a sintering process. The purpose of the present invention is to provide a method for manufacturing a joined rod-like body of a composite material having a small cross section and an elongated shape, preferably a cylindrical body having a small diameter, so that a drill having excellent wear resistance and rigidity can be easily and inexpensively manufactured therefrom. shall be.

A further object of the present invention is to easily and efficiently drill holes in difficult-to-cut substrates such as glass epoxy substrates.
Our goal is to provide long-life drills at low prices.

Furthermore, it is an object of the present invention to provide a method for producing a small cross-section composite material rod as an intermediate product that can easily produce elongated members that require a hard tip, such as the head of a dot printer. .

Structure of the Invention The present inventors manufactured a composite sintered body block by hot pressing a composite material block with a large cross-sectional area, and then manufactured a composite sintered body block with a small diameter in the direction of the material layer thickness of the block by electrical discharge machining using a pipe-shaped electrode. By hollowing out a cylindrical body, or by hollowing out a rod-shaped body by processing with a highly focused and high-energy beam such as an electron beam, laser beam, or ion beam, a composite sintered product with a small diameter, elongated, and hard head can be produced. It was a success in providing a cylindrical or rod-shaped body of material.

That is, according to the present invention, a first material layer for a hard sintered body containing 50% or more of diamond powder or high-pressure phase boron nitride powder; The hard sintered body and the second material layer to be joined are stacked in the same hot press container in the pressing direction, hot pressed under high temperature and high pressure to sinter the first material layer, The obtained hard sintered body was joined to the second material layer side to form a composite material block having a layer of hard sintered body with a predetermined thickness, and a pipe-shaped electrode was used from the composite material block. By hollowing out a cylindrical body in the material layer thickness direction by electrical discharge machining, a hard sintered body having a cross section with a diameter of 3 mm or less and 1/6 or less of the thickness in the material layer thickness direction of the composite material block is made into a head. Provided is a method for manufacturing an elongated composite material cylinder, which comprises cutting out two or more elongated composite material cylinders prepared for use.

Furthermore, according to the present invention, rods may be hollowed out from the composite material block in the direction of the material layer thickness by high-energy beam machining such as an electron beam, laser beam, or ion beam.

When hot pressing and sintering composite materials,
According to the invention, the axial length of the composite block must be no more than three times, preferably twice, the equivalent diameter DE. If a composite material block with an axial length exceeding three times is hot pressed, the pressure distribution within the composite material block will become irregular, resulting in bending or the like. In this specification, equivalent diameter means a value converted to the diameter of a circle having the same cross-sectional area.

The average particle size of the diamond powder or high-pressure phase boron nitride powder is preferably 30 μm or less, and a composite sintered material with excellent wear resistance and rigidity can be obtained with a diamond or high-pressure phase boron nitride sintered body having a particle size within this range.

However, when making chips for cutting tools using diamond powder, if diamond powder with an average particle size exceeding 10 μm is used as a raw material, the cutting edge of the cutting tool obtained by processing this composite sintered material cylinder The hard sintered part is preferably made of diamond or high-pressure phase boron nitride with a diameter of 10 μm or less, since the hard sintered part cannot be formed sharply and therefore does not have high performance.

According to a preferred feature of the invention, the axial length of the hard sintered portion is between 0.3 and 2 mm.

When the first material layer is mainly composed of diamond powder, it contains diamond powder alone or contains 70% or more of diamond, with the remainder being Fe, Co or
There is a mixed powder to which binder powder whose main component is Ni is added. A preferred example of the first material layer of diamond powder is a mixed powder of 70% or more diamond powder and WC-5 to 15% Co powder.

Note that when diamond alone powder is used as the material for the first material layer, the binder component in the second material layer is dissolved into the first material layer powder during sintering of the first material layer. Sintering of the first material layer is achieved by soaking.

When the first material layer is high-pressure phase boron nitride-based, high-pressure phase boron nitride powder alone, or 50% or more of high-pressure phase boron nitride and carbides or nitrides of group 4a, 5a, or 6a elements,
Some are sintered with carbonitride and aluminum and/or silicon added as binders.
Here, high-pressure phase boron nitride means cubic boron nitride and wurtzite boron nitride.

The second material layer forming the support portion is made of a so-called cemented carbide, that is, a carbide, nitride, carbonitride, boride, silicide, or a mutual solid solution carbide of elements of groups 4a, 5a, and 6a of the periodic table. Fe, Co or Ni
sintered alloys or cermets bonded with iron group metals, or their powder raw materials. An example of a cermet is carbide (Mo,w)C with Ni or
Some are bonded with iron group metals such as Co.

Another second material layer may be a sintered alloy called a so-called heavy metal containing 80 to 98% by weight of W with the remainder being Ni-Fe or Ni-Fe-Cu, or a powder raw material thereof.

The second material layer may be a solid cemented carbide that has already been sintered, or may be a powder of a cemented carbide material. However, in view of handling convenience during hot pressing and ease of applying high pressure, it is preferable to use a sintered cemented carbide block.

One of the important features of the method for manufacturing a composite material rod or cylinder of the present invention is that the hard sintered part and the support part are joined during the sintering process of the hard sintered part.

Therefore, the components of the second material layer need to be materials that can be bonded to the first material layer during the sintering process of the first material layer.

However, within the range of the components of the hard sintered part and the support part mentioned above, such combinations are infinite, and in the sintering process of diamond or high-pressure phase boron nitride by hot pressing under high pressure and high temperature, the above-mentioned combinations are possible. The iron-based metal binding material in the support member is infiltrated into the support member, and a strong bond between the hard sintered part and the support part can be easily achieved. Therefore, it goes without saying that those skilled in the art can select the components of the hard sintered part and the supporting part as necessary within the above-mentioned range. Further, the high-pressure phase boron nitride powder can be sintered alone as described above, and bonding with the support portion is achieved during the sintering process.

Furthermore, according to one aspect of the present invention, the first
An intermediate bonding layer having a thickness of 0.5 mm or less is placed between the first material layer and the second material layer, and hot pressing is performed.

The intermediate bonding layer is made of less than 70% high-pressure phase boron nitride and the remainder is one of carbides, nitrides, carbonitrides, or borides of Ti, Zr, and Hf in group 4a of the periodic table, or a mixture thereof. Those mainly composed of solid solution compounds and those containing Al and/or Si.
Those containing 0.1% by weight or more are preferable.

Furthermore, according to one aspect of the present invention, the second
The material layer, that is, the support portion is composed of two or more material layers in the axial direction. One such example is that the supporting side layer of the second material layer is WC-Co, and the hard head side layer is made of carbide (Mo,w)C with Ni or
Some are made of cermets bonded with iron group metals such as Co.

Furthermore, the first material layer is placed above and below the second material layer, hot-pressed, and the resulting composite material block is coaxially hollowed out into a rod-like body or cylinder with a small cross section, and hard heads are attached at both the top and bottom ends. It is also possible to produce a rod-shaped body having a section.

Next, the shape of the composite sintered material cylinder obtained by the manufacturing method of the present invention will be explained.

The attached FIGS. 3a and 3b are perspective views of examples of composite material cylinders obtained by the manufacturing method of the present invention.

In the cylindrical body of composite sintered material shown in FIG. 3a, the hard sintered part 21 is directly joined to the support part 22.

On the other hand, in the composite sintered material cylindrical body shown in FIG.

However, the composite material rod-shaped body hollowed out from the composite material block by a high-energy beam such as an electron beam, laser beam, or ion beam according to the present invention is not limited to a cylindrical shape, but may of course be prismatic.

The composite sintered material cylinders or rods obtained by the method of the invention have a cross section with a diameter or equivalent diameter of 3 mm or less. Composite material cylinders or rods with cross-sections of diameters exceeding 3 mm or equivalent diameters are unsuitable as materials for drilling holes in printed circuit boards, and even if they are used after grinding, the grinding cost becomes large and uneconomical. .

Moreover, the length of the hard sintered part 21 in the axial direction is 0.3~
The range is 2mm. If the length is less than 0.3 mm, no improvement in machinability can be expected when used as the tip of a drill, and if the length exceeds 2 mm, a large amount of expensive diamond powder etc. will be used, which is uneconomical. Further, cylinders or rods having a diameter of more than 3 mm can be manufactured with relatively good quality by conventional methods other than the method of the present invention.

Furthermore, the length of the support part 22 needs to be five times or more the length of the hard sintered part 21. When manufacturing a drill, it is necessary to ensure the length of the face of the drill and embed the end in the shank, so as described above, a support portion that is five times or more longer is required.

Next, FIG. 4 shows an example in which a rod-shaped or cylindrical composite material obtained by the manufacturing method of the present invention is applied to a drill.

As shown in FIG. 4a, a composite material rod (in the illustrated example, a cylindrical body) is attached to the tip of the shank 25 of the drill.
A hole 26 having substantially the same diameter is bored. Push the support side end of the composite material rod-shaped body 23 into this hole 26,
Fix it. At this time, brazing material may be dropped into the hole 26 and brazing may be performed.

As shown in FIG. 4a, the composite material rod-shaped body 23 fixed to the shank is processed with a blade, and as shown in FIG. 4b.
I obtained a drill as shown below.

Next, to explain the method of hollowing out the composite material rod-shaped body shown in FIGS. 3 and 4, the composite sintered body block 33 obtained by hot pressing as described above will be described.
As shown in FIG. 5a, a diamond sintered body layer 31 with a thickness of 1 mm and a cemented carbide layer 3 bonded thereto are formed.
2, and when an intermediate bonding layer is included, the diamond sintered body layer 31 and the cemented carbide layer 32 are bonded via the intermediate bonding layer as shown in FIG. 5b.

As shown in Fig. 6, these composite sintered blocks have an equivalent diameter of 3 in the coaxial direction with the composite sintered blocks.
A cylindrical body with a cross section of mm or less is hollowed out by electric discharge machining using a pipe-shaped electrode, and the cylindrical body is hollowed out as shown in Fig. 3a.
A composite material cylinder having a hard head as shown in FIG.

In this electric discharge machining method using a pipe-shaped electrode, a high voltage is applied between the electrode and the composite sintered block while maintaining a constant gap between the electrode and the processed part of the composite sintered body block. Alternatively, the pipe-shaped electrode and the composite sintered block are placed facing each other in an insulating liquid, and a voltage is applied.

FIG. 7 shows a pipe-shaped electrode used in the method of the invention. The electrodes shown in FIG.
c is installed vertically. Pipe electrode 4
1 consists of a hollow cylindrical body as shown in Fig. 7b,
A gas vent hole 42 is provided in the upper portion thereof, and constitutes an escape hole for gaseous material vaporized by electric discharge.

FIG. 8 shows an electrode means comprising a large number of pipe-shaped electrodes, FIG. 8a is a side view thereof, and FIG. 8b is a plan view showing the arrangement of the composite sintered body block and the electrodes. The pipe-shaped electrode used in the method of the present invention is not limited to these, but may be of any structure as long as it can be hollowed out of a cylindrical body from the composite sintered block. For example, a honeycomb-shaped electrode may be used.

However, the electric discharge machining method itself using a pipe-shaped electrode is not a direct object of the present invention and is known per se, so no further explanation will be given.

On the other hand, when processing with a highly convergent, high-energy beam such as an electron beam, laser beam, or ion beam, a rod-shaped body with an arbitrary cross section is hollowed out from a composite sintered block, and the present invention also applies to these high-energy beam processes. Since this is not a direct subject of this and is known per se, no further explanation will be given.

Effects of the Invention By the method of the present invention, the head has a hard sintered body, which was very difficult to obtain with the conventional technology, the cross section perpendicular to the axis is 3 mm or less, and the ratio of the diameter to the total length is 1. : It is possible to produce an elongated composite sintered cylinder having a diameter of 6 or more.

Not only is it difficult to make an elongated composite sintered cylindrical body having such dimensions using conventional techniques, but even if it could be made, its durability would be extremely short, making it completely impractical.

In contrast, the present invention makes it possible for the first time to industrially manufacture a practical, long-life, high-performance small-diameter drill element for drilling small-diameter holes in a printed circuit board made of glass fiber-reinforced epoxy resin, which is generally referred to as a glass-epoxy board. provided a method.

The elongated composite sintered cylindrical body according to the present invention can be used in a wide range of fields, such as long-life head elements of dot printers, in addition to the above-mentioned small-diameter drill elements, and greatly contributes to reducing production costs and improving quality. It is.

Hereinafter, the manufacturing method of the present invention will be explained with reference to Examples. However, these Examples are merely illustrative of the present invention, and do not limit the scope of the present invention in any way.

In this specification, % is expressed in volume percent unless otherwise specified.

Example 1 WC-12%Co with an outer diameter of 18 mm, an inner diameter of 14 mm, and a height of 15 mm.
Cemented carbide ring, outer diameter 14mm, height 12mm WC−
12%Co cemented carbide cylinder block, outer diameter 14mm, thickness 0.5mm WC-12%Co cemented carbide disc and grain size 0.5μ
A mixed powder was prepared, consisting of 85% diamond powder with a particle diameter of 0.5 μm or less and WC-15% Co cemented carbide powder with a particle size of 0.5 μm or less.

A superalloy cylindrical block is inserted into the inner diameter of the superalloy ring, and the mixed diamond powder is filled into a recess with a diameter of 14 mm and a depth of 3 mm formed by the inner surface of the cemented carbide ring and the top surface of the cemented carbide cylindrical block, and then processed. After pressing the mixed powder to a height of 1.5 mm and capping it with a cemented carbide disk, place it in an ultra-high pressure sintering device and press it.
Sintering was performed for 15 minutes at a temperature of 55 kb and 1370°C.
After cooling, the upper cemented carbide disk of the enclosure was removed by depressurization and removed by grinding, and a 1 mm thick sintered diamond layer was bonded to the top surface of the 12 mm high cemented carbide support and formed around it. A composite block was obtained in which the cemented carbide ring was also bonded to the support and to the sintered diamond layer.

As shown in Fig. 6, this composite block was installed in an electrical discharge machine equipped with a pipe-shaped electrode, and subjected to electrical discharge machining to produce a diameter of 1 mm from the axial direction of the composite block.
A cylindrical body was hollowed out using a round bar with a length of 13 mm, the support part of which was made of WC-12% Co cemented carbide, and a sintered diamond layer of 1 mm in length was fixedly formed at one end.

Example 2 Outer diameter made of WC-12%Co cemented carbide, respectively
18mm, inner diameter 14mm, height 20mm ring, outer diameter 14
mm, 18 mm height cylindrical block, outer diameter 14 mm, thickness
0.5mm disk and 90 diamond powder with particle size of 3μm
Mixed powder consisting of % and remainder Co powder, particle size 3μm
High-pressure phase boron nitride (hereinafter referred to as cubic boron nitride)
60% powder (abbreviated as CBN) and the remainder (TiN−10
A mixed powder consisting of a powder having a composition of (wt% Al) was prepared.

After applying a solution of the CBN mixed powder in a solvent to a thickness of 50 μm on the top surface of a cemented carbide cylindrical block, the solvent was removed by heating, and the cemented carbide cylindrical block subjected to this treatment was made into a cemented carbide ring with an inner diameter of 50 μm. inserted into.

Next, the diamond mixed powder was filled into the recess formed by the inner surface of the cemented carbide ring and the top surface of the cemented carbide cylindrical block coated with the CBN mixed powder, and then pressure molded to form a 1.8 mm thick block. After forming the diamond mixed powder layer, it was covered with a cemented carbide disk.

Next, this container was placed in an ultra-high pressure sintering device and sintered at a pressure of 55kb and a temperature of 1400℃ for 10 minutes.
After cooling and reducing the pressure, the container was taken out. When the upper cemented carbide disk of the container is removed by grinding, a 1.2 mm thick sintered diamond layer is bonded to the top surface of the 18 mm high cemented carbide support via a 25 μm thick sintered CBN layer, and the surrounding A composite block was obtained in which the cemented carbide ring was bonded to the support and to the sintered diamond layer.

This composite block was installed in an electric discharge machine equipped with a pipe-shaped electrode, and the support part was made of WC-12% Co cemented carbide using a round bar with a diameter of 2 mm and a length of 19.2 mm from the axial direction of the composite. A cylindrical body was hollowed out, and a sintered diamond layer with a length of 1.2 mm was bonded to one end of the cylindrical body through a sintered CBN interface layer with a thickness of 25 μm.

Example 3 ( _Mo7 , _W3 ) Made of C-11%Co cemented carbide,
A cylindrical block with an outer diameter of 24 mm and a height of 25 mm with a circular recess of 20 mm in diameter and 3 mm in depth on the top surface, a WC-12% Co cemented carbide disk with an outer diameter of 20 mm and a thickness of 0.5 mm, and a grain size of 0.5 μ.
A mixed diamond powder was prepared, consisting of 80% diamond powder of m and the remainder WC-15% Co cemented carbide powder with a particle size of 0.5 μm or less.

This diamond mixed powder was filled into the recess on the upper surface of the cemented carbide cylindrical block and then pressurized to a height of 2.3 mm.
A layer of diamond mixed powder was formed. Next, this was covered with a cemented carbide disk, placed in an ultra-high pressure sintering device, and sintered at a pressure of 55 kb and a temperature of 1400°C for 15 minutes.

After sintering, the sealed container is taken out and the cemented carbide lid on the top surface is ground and removed to reveal a sintered diamond layer with a thickness of _1.5 mm in the circular recess on _the top surface. A composite block was obtained that was firmly bonded to the %Co alloy container.

This composite block was mounted on an electron beam processing machine, and the supporting body part was (Mo ₇ , W ₃ )C-11%Co using a round bar with a diameter of 2 mm and a length of 23.5 mm from the axial direction of the composite block. A rod-shaped body made of cemented carbide and having a 1.5 mm long sintered diamond layer fixedly formed on one end was hollowed out.

Example 4 WC-12%Co with an outer diameter of 18 mm, an inner diameter of 14 mm, and a height of 15 mm.
Cemented carbide ring, outer diameter 14mm, height 12mm 96% by weight
Cylindrical block made of W-3wt%Ni-1wt%Cu alloy, WC-12%Co with outer diameter 14mm and thickness 0.5mm.
Cemented carbide disc and 85% CBN with grain size 3μm and the remainder
After mixing TiN _0.82 powder and Al powder at a weight ratio of 80:20, heat treatment was performed in a vacuum furnace at 1000℃ for 30 minutes, and the powder was ground to 0.3 μm and CBN was obtained.
A mixed powder was prepared.

A W alloy cylindrical block is inserted into the inner diameter of the cemented carbide ring, and the CBN mixed powder is filled into a recess with a diameter of 14 mm and a depth of 3 mm formed by the inner surface of the cemented carbide ring and the upper surface of the W alloy cylindrical block. Pressurize to height
A 1.7 mm CBN mixed powder layer was formed. Next, a cemented carbide disc is placed over the lid, and the entire cemented carbide container is placed in an ultra-high pressure sintering device, after which pressure is applied.
Sintering was performed at 50kb and 1250℃ for 20 minutes.

After sintering, take out the cemented carbide container and remove the WC on the top surface.
-12%Co cemented carbide lid height 12mm when removed by polishing
A composite block was obtained in which a sintered CBN layer with a thickness of 1 mm was bonded to the upper surface of the W alloy support part, and a cemented carbide ring was bonded to the support body and the sintered CBN layer around the periphery.

This composite block was placed in an ion beam processing machine, and the ion beam was used to form a round bar with a diameter of 1 mm and a length of 13 mm from the axial direction of the composite block, and the support part was 96% W-3% Ni-1% Cu. Made of alloy,
A rod-shaped body with a 1 mm long sintered CBN fixedly formed at one end was hollowed out.

Example 5 WC-12%Co with an outer diameter of 40 mm, an inner diameter of 36 mm, and a height of 40 mm.
Cemented carbide ring, outer diameter 36mm, height 34mm WC-12
%Co cemented carbide cylindrical block, outer diameter 36mm, thickness 0.5
mm WC-12%Co cemented carbide disk and grain size 3μm
CBN powder 60% by volume and remainder (TiN-10% by weight Al)
A CBN mixed powder consisting of powder with the following composition was prepared.

First, the CBN mixed powder was pressure-molded into a disk with a diameter of 36 mm and a thickness of 2.5 mm, and the inner diameter of the cemented carbide ring was molded from the bottom to the cemented carbide disk, CBN molded body, cemented carbide cylindrical block, and CBN molded body. , cemented carbide disks were stacked in this order, and the entire container was placed in an ultra-high pressure sintering device and sintered at a pressure of 40 kb and a temperature of 1200° C. for 20 minutes.

After sintering, when the block is taken out and the top and bottom cemented carbide lids are ground and removed, a sintered CBN layer with a diameter of 36 mm and a thickness of 1.5 mm is firmly formed on the top and bottom surfaces of the 34 mm high cemented carbide cylindrical block, and the surrounding area is made of cemented carbide. A composite block covered with an alloy ring was obtained.

Next, this composite block is mounted on a laser processing machine, and a sintered CBN layer with a length of 1.5 mm is fixed to both ends of a round bar with a diameter of 2.5 mm and a length of 37 mm using a laser beam from the axial direction of the composite block. I hollowed out the formed thing.

This round bar was further cut into two parts at the center in the length direction, resulting in a round bar with a diameter of 2.5 mm and a length of 18 mm.The support part was made of WC-12%Co cemented carbide and one end had a length of 1.5 mm.
A rod-shaped body was obtained in which a sintered CBN layer of mm thick was firmly formed.

[Brief explanation of the drawing]

FIG. 1 shows the structure of a conventional composite diamond sintered body. FIG. 2 shows a drill in which a conventional composite sintered body is fixed to the cutting edge. Figures 3a and 3b each show an example of a composite sintered material cylinder produced by the method of the invention. FIG. 4a illustrates a method of making a drill using a composite cylinder obtained by the method of the invention, and FIG. 4b shows the drill. FIG. 5a shows an example of a composite block obtained according to the method of the invention, and FIG. 5b shows an example of a composite block with an intermediate joint. 6th
The figure shows the location of hollowing out a cylinder from a composite block according to the invention. FIG. 7 shows a pipe-shaped electrode used in the method of the present invention, FIG. FIG. 2 is a schematic diagram of a pipe-shaped electrode. FIG. 8 shows an electrode means comprising a large number of pipe-shaped electrodes, FIG. 8a is a side view thereof, and FIG. 8b is a plan view showing the arrangement of the composite sintered body block and the electrodes. (Main reference numbers), 11... Sintered diamond layer of conventional diamond tool, 12... Cemented carbide support, 13... Conventional composite sintered diamond chip, 15... Shank, 21... ...Hard sintered part of composite sintered material cylindrical body according to the method of the present invention, 2
2... Support part, 23... Composite sintered material cylindrical body of the present invention, 24... Intermediate joint part, 31... Hard sintered part of composite material block, 32... Support part, 33...
Composite material block, 34... Middle joint, 40...
... Electrode support part, 41 (41a, 41b, 43
c)... Pipe-shaped electrode, 42... Gas vent hole.

Claims (1)

[Scope of Claims] 1. A first material layer for a hard sintered body containing 50% or more of diamond powder or high-pressure phase boron nitride powder; The hard sintered body and the second material layer to be joined are stacked in the same hot press container in the pressing direction, and hot pressed under high temperature and high pressure to sinter the first material layer. , the obtained hard sintered body is joined to the second material layer side to form a composite material block having a layer of the hard sintered body with a predetermined thickness, and an electrode having a hollow cylindrical portion in the axial direction is formed. By hollowing out a cylindrical body from the composite material block in the material layer thickness direction using electrical discharge machining, the cylinder has a cross section with a diameter of 1/6 or less of the material layer thickness direction of the composite material block and 3 mm or less. 1. A method for producing an elongated composite material cylinder, the method comprising cutting two or more elongated composite material cylinders each having a hard sintered body at the head. 2. The method for manufacturing an elongated composite material cylinder according to claim 1, wherein the diamond powder or high-pressure phase boron nitride powder in the hard sintered part has an average particle size of 30 μm or less. 3. The method for manufacturing an elongated composite material cylinder according to claim 1, wherein the diamond powder or high-pressure phase boron nitride powder in the hard sintered part has an average particle size of 10 μm or less. 4 The second material layer is made of materials from periodic table 4a, 5a,
The elongated composite material cylinder according to any one of claims 1 to 3, which is a cemented carbide made by bonding carbides of group 6a elements or their mutual solid solution carbides with iron group metals. How the body is manufactured. 5. Claims 1 to 3, characterized in that the second material layer contains 80 to 98% by weight of W, with the remainder being an alloy consisting of Ni-Fe or Ni-Fe-Cu. A method for manufacturing an elongated composite material cylinder according to any one of the above. 6. Claim 1, characterized in that hot pressing is performed with an intermediate bonding layer having a thickness of 0.5 mm or less arranged between the first material layer and the second material layer.
6. A method for manufacturing an elongated composite material cylinder according to any one of items 5 to 6. 7. The method for manufacturing an elongated composite material cylinder according to any one of claims 1 to 6, wherein the electrode having the hollow cylindrical portion in the axial direction is a pipe-shaped electrode. 8. A first material layer for a hard sintered body containing 50% or more of diamond powder or high-pressure phase boron nitride powder, and a hard sintered body of the first material in the sintering process of the first material layer. The second material layer to be joined is stacked in the same hot press container in the pressing direction, hot pressed under high temperature and high pressure to sinter the first material layer, and the obtained hard sintered material layer is sintered. The compact is joined to the second material layer side to form a composite material block having a layer of hard sintered compact with a predetermined thickness, and processed by high-energy beam processing such as an electron beam, laser beam, or ion beam. A hard sintered body having a cross section with an equivalent diameter of 1/6 or less of the thickness of the composite material block in the material layer thickness direction and 3 mm or less by hollowing out a rod body from the composite material block in the material layer thickness direction. 1. A method for producing an elongated composite material rod, the method comprising cutting two or more elongated composite material rods having a head thereof. 9. The method of manufacturing a slender composite material rod according to claim 8, wherein the diamond powder or high-pressure phase boron nitride powder in the hard sintered part has an average particle size of 30 μm or less. 10. The method for manufacturing a slender composite material rod according to claim 8, wherein the diamond powder or high-pressure phase boron nitride powder in the hard sintered part has an average particle size of 10 μm or less. 11 The above-mentioned second material layer is made of materials from periodic table 4a, 5a,
The elongated rod-shaped composite material according to any one of claims 8 to 10, which is a cemented carbide made by bonding carbides of group 6a elements or their mutual solid solution carbides with iron group metals. How the body is manufactured. 12. Claims 8 to 10, characterized in that the second material layer contains 80 to 98% by weight of W, with the remainder being an alloy consisting of Ni-Fe or Ni-Fe-Cu. A method for producing an elongated composite material rod according to any one of the above. 13 Claims 8 to 12, characterized in that hot pressing is performed with an intermediate bonding layer having a thickness of 0.5 mm or less arranged between the first material layer and the second material layer. A method for producing an elongated composite material rod according to any one of the above.