JPS61192337A - Apparatus for generating ultra-high pressure - Google Patents

Abstract

PURPOSE:To make it possible to prolong the life of the titled apparatus and to enlarge said apparatus in low cost, by using powder sintered tool steel in the innermost layers of a high pressure cylinder and an anvil. CONSTITUTION:For example, the alloy having the composition shown by a table I is used as powder sintered tool steel to be melted in a high frequency melting furnace and a spherical powder with an average particle size of 250mum is obtained by a nitrogen gas atomizing method. A metal capsule made of super-soft steel is filled with said powder at density of 60-70% and, after degassing and hermetical sealing, the press densification and sintering of the powder is performed in an argon gaseous atmosphere under a desired condition in a hot static pressure molding press apparatus and the molded sintered powder is further heated in a forging heating furnace and, after divided into lumps by a hammer, said lumps are annealed in an annealing furnace, polished, again processed in the annealing furnace and roughly cut at last. The hardened and tempered powder sintered tool steel forged material is subjected to polishing and finishing processing to be formed into a cylinder core 1 and an anvil core 7 which are, in turn, subjected to cold press fitting.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a belt device type ultra-high pressure generator used in the production of diamond, cubic boron nitride, etc.

[Prior art] I5 The types of ultra-high pressure generators are extremely diverse.

The most common ones are belt device type and girdle.

Device type, dual type piston cylinder device type, opposing.

Anvil device type, cubic anvil device type′, regular four-sided.

Body anvil device types have been developed and are in use. 2.
.

However, some of these devices utilize ultra-high pressure.

The operations used in industrial production are comparative.

It is a belt device type that is simple and has a relatively large internal volume compared to the size of the device. Figure 2 is a book.

FIG. 1 is a perspective view of the overall structure of a typical belt device type ultra-high pressure generating device used in the invention. The belt device type ultra-high pressure generator shown in Figure 2 does not have a drive mechanism itself.
It consists of a high-pressure cylinder A, an anvil B, and a press machine containing a drive/mechanism C.・Ambi 10 B with a pointed tip in the shape of Mt. Fuji is installed on the press machine facing from above and below, and high pressure cylinder A is installed on the press machine.
can be freely moved on the guide rail F by the moving table E.・Figure 3 shows a cross-sectional perspective view of a typical conventional high-pressure cylinder A and an upper anvil B. Since the upper and lower anobiles 15B are symmetrical, the cross section of the lower anobile is omitted.

It is. As shown in Figure 6, high pressure cylinder A and upper and lower holes.

Building B is combined to form one pressure space G.

This is done by the drive mechanism C that is built into the press.

When lower anvil B is pushed upward, a pressure space is created.

Ultra-high pressure is generated in G. A can-shaped sample cell H shown in Fig. 4 is confined within this pressure space.
0. Steel 11. Molybdenum 121 Salt 16. It is composed of graphite, lead 14, etc., and graphite or scrap diamond 1 is placed in this graphite container.
5. Seal iron/nickel 16, etc. as shown in the diagram, and add poppy seeds to this in the iron/nickel.Diamond 17
Insert one or more of them.・Approximately 60,000 atmospheres of ultra-high pressure is applied to the sample cell H. ・Meanwhile, approximately 3,000 atmospheres of ultra-high pressure is applied to the graphite.
Pass a large current of 18 amperes [...about 1.5 amps through the center]
When heated to 007:, the raw material melts into a slurry, forming a state similar to that of hundreds of underground magmas, and the carbon atoms of the scattered graphite pass through the iron and nickel layers as shown by the broken lines. Seed crystal.

Crystals form again on top of the diamond and grow into large diamonds.

From the above, in the ultra-high pressure generator.

High pressure cylinder A and upper and lower A receive the highest pressure.

It can be seen that the material selection for building B is very important.

In particular, since pressure as high as 60,000□1 atmosphere acts on the inner wall surface of the high-pressure cylinder, the thickness is simple.

The inner cylinder cannot withstand any material. .

Therefore, as shown in Fig. 6, the high-pressure cylinder Δ has a multilayer "fitting" structure so that it can withstand high internal pressure by applying pre-pressurized cotton. From the experimental data, the multi-layered structure has higher pressure resistance than the one-piece structure.

It has been found that the strength is increased, and the structure shown in FIG. 6 is generally employed. ``Conventionally, cemented carbide has been used for the portions of these high-pressure cylinders and upper and lower anvils that face the super-10 high-pressure generation space G.

[Problem that the invention seeks to solve]

However, with conventional cemented carbide, (1) the occurrence and progression of cracks and chips are severe and the lifespan is shortened.
Hot isostatic pressure is not sufficient for sintering.

Even if you use HIP processing, pinholes etc.

Defects cannot be completely prevented, especially large ones.

The product also suffers from a decrease in strength and lack of strength due to the mass effect.

Since the probability of failure increases rapidly, large parts are manufactured. .

, 5.

is difficult.

(2) Cemented carbide contains large amounts of expensive elements.

It is expensive because it has poor workability.

There were problems such as.

[Means for solving problems]

The object of the present invention is to provide an ultra-high pressure generator that solves the above-mentioned problems.

A powder sintering tool is attached to at least the part of the high-pressure cylinder and/or annovil facing the ultra-high pressure generation space.

This is a belt device type ultra-high pressure generating device characterized by the use of steel.

[Effect]

The present invention provides high-pressure cylinders and anvils with
This is based on the fact that high tool life has been achieved by using powder sintered tool steel.

The ultra-high pressure generator of the present invention uses cemented carbide.

The reason why it has a longer lifespan than conventional equipment is due to high performance.

Has not been disassembled. High pressure cylinder and anobil.

Since the pressure gradient is especially steep in the part facing the ultra-high pressure generation space, the inside of the material is based on this pressure gradient.

, 4.

Measured in the usual way to prevent plastic flow.

The hardness of the material, that is, the material to be measured with an indenter of a predetermined shape.

The dog compresses and compresses the load to the size of its indentation.

It is considered reasonable to use a carbide base metal that exhibits a high value of hardness calculated by the ratio of grain size. 'but,
In reality, cracking and chipping occur when using cemented carbide, and this phenomenon progresses rapidly at high hardness levels.

At the same time, it is clear that it is necessary to have high toughness. These two characteristics are generally contradictory.

Therefore, it is considered necessary to maintain a balance between these two characteristics in accordance with the application and usage conditions. .

The material used in the present invention has lower hardness than cemented carbide but high toughness, so the overall balance of both properties meets the conditions for use in a belt device type ultra-high pressure generator.

It is believed that this will result in a long life. 15 [
Example] The present invention will be described in detail below using an example. .

FIG. 1 shows a powder sintered tool steel showing an embodiment of the present invention.

High pressure cylinder A and anvil using the innermost layer.

In FIG. 1, which is a longitudinal sectional view of B, 1 is a cylinder core 2°, 2 is a shim, 3 is a first ring, and 4 is a second ring.

5 is the third ring, 6 is the safety ring, 7 is the anvil core, 8 is the first ring for tightening the anvil, and 9 is the anvil.

The second ring for tightening the building is shown. In this embodiment, powder sintered tool steel was used for the cylinder core 1 and anvil core 7 shown in FIG. 1, and this will be explained. Table 1 An alloy having the composition shown in Table 1 was melted in a high frequency melting furnace.

The average particle size was 250μ by nitrogen gas atomization.

A spherical powder was obtained. This was filled into a metal capsule made of extremely mild steel at a density of 60 to 70 cm, degassed and sealed, and then heated to 1.180 cm using a hot isostatic pressing machine (HIP).
.

In a high temperature, high pressure argon gas atmosphere of 1,000 atmospheres.

Consolidation and sintering of the powder was done all at once. Plus this.

was heated in a forging heating furnace and bloomed with a hammer.

After that, annealing was performed in an annealing furnace. Then, by grinding 2.1
The surface capsule is removed and heated in a forging furnace.

After finish forging with a hammer, it is fired again in an annealing furnace.

It was dulled. After rough cutting the powder sintered tool steel forging made in this way and quenching and tempering it, the first
As shown in the figure, the cylinder core 1 and anvil core 7 were subjected to a grinding finish, and then cold press pressure and pre-compression were applied by hand.During press-fitting, special attention was paid to the consistency of the taper angle of the press-fitting surface and the finish. It goes without saying that surface roughness and tightening allowance are important for machining accuracy.
The microstructure of powder sintered steel and tool steel made through more than 10 processes has carbides finely and uniformly dispersed, and has excellent heat treatment characteristics, toughness, and grindability. It has been confirmed that the quality is significantly superior to that of ordinary welded tool steel that does not use. Table 2 shows the powder sintered tool steel forgings used in this example.

A comparison of the mechanical properties of this and conventional cemented carbide is shown. .

Margin below.

, 7.

Table 2 Compared to conventional cemented carbide, the material of the present invention is not only cheaper and superior in terms of grindability and toughness, but also has lower hardness as shown in Table 2. Although it is low in strength, it has excellent tensile strength and compressive strength. .

In this example, forging is performed after powder sintering.
Defects such as pinholes during sintering are completely removed, and the decrease in strength due to mass effect is also significantly reduced.Furthermore, regardless of the size and shape during sintering, by forging, it can be formed into a ring shape or other large size. It has the feature that it can be applied to members with large diameters, and can also be used for ultra-high pressure/pressure generating devices that are expected to become even larger in the future.

The high-pressure cylinder and anvil of this example are currently undergoing use tests and are currently using conventional cemented carbide! ..., 8
.

The lifespan is approximately twice that of those using gold. [Effects of the Invention] As described above, the ultra-high pressure generator of the present invention has the following advantages.

Longer life than conventional equipment using cemented carbide.

It is something to be achieved. In addition, it is inexpensive and can be made larger, leading to the development of belt device type ultra-high pressure generators.

This is something that can make a significant contribution.

[Brief explanation of drawings]

FIG. 1 shows a high-pressure cylinder according to an embodiment of the present invention. Fig. 2 is a longitudinal cross-sectional view of Anobil, Fig. 2 is a perspective view of the overall structure of the 10-belt device type ultra-high pressure generator used in the present invention, and Fig. 3
The figure shows a cross-sectional perspective view of a typical conventional high-pressure cylinder and anvil, and FIG. 4 shows a cross-sectional perspective view of a sample cell inserted into the pressure space of the belt device type ultra-high pressure generator main device.
I5Δ...High pressure cylinder, Dan...Upper, lower anobyl. C... Drive mechanism, D... Press machine, E...
Moving table, F... Guide rail, G... Pressure space, H... Sample cell, 1... Cylinder core, 2... Shim s 203...
・First ring, 4...Second ring, “
5...Third ring, 6...Safety ring,
7... Anvil core, 8... First ring for anvil tightening, 9... Second ring for anvil tightening.

Claims (1)

[Claims] In belt-type ultra-high pressure generators used for the production of diamonds, cubic boron nitride, etc., powder sintered tool steel is used in at least the portion of the high-pressure cylinder and/or anvil that faces the ultra-high pressure generation space. Characteristic belt device type ultra-high pressure generator.