JP2945956B2 - Impact sample recovery method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact sample recovery method. More specifically, the present invention
The present invention relates to a new impact sample recovery method that is useful for creating new materials and high-performance and high-performance materials.

[0002]

2. Description of the Related Art Conventionally, various devices have been devised to create high-performance and high-performance substances and materials, such as vapor phase growth, liquid phase growth, sintering, and impact pressure. The methods of synthesizing materials using various means have been proposed and put to practical use. Among these various methods,
The powder pressing technique by the impact pressure is one of the methods that are receiving attention. In this method, for example, a sample powder is sealed in a collection container without any gap, and a flying object accelerated by a one-stage gun or a two-stage light gas gun collides with the projectile, and is contained therein. It is characterized in that an impact pressure is instantaneously generated in the powder.

[0003] In this method, that is, the impact sample recovery method, the duration of the impact pressure is extremely short, on the order of microseconds, the surface of the powder particles is instantaneously strongly heated, and the pressure is 10 GPa or more. Because pressure is possible,
As a result, it becomes possible to obtain a bulk of almost true specific gravity while remaining amorphous without being crystallized.
It is expected as a technique for synthesizing diamond and c-BN, additive-free sintering, and sintering of composite materials.

A conventional method for recovering a shock sample will be further described with reference to the drawings. For example, as shown in FIG.
The sample (2) is placed in a collection container (3) for protecting it from shock wave destruction, and the collection container (3) is stored in a storage body (1) for storing and protecting it. At the same time, cover the sample (2) with the screw lid (4),
Flying object (8) consisting of servo (6) and metal flying plate (7)
Is accelerated by, for example, explosives or explosives, and collided with the collection container (3).

However, such a conventional impact sample recovery method is not necessarily a completed technique as a method for synthesizing a material that requires higher functionality and higher performance. This is because, in the conventional impact sample recovery method, the pressure and temperature do not rapidly decrease or drop in the process of releasing the impact pressure and impact temperature, and the sample is cooled in a very slow adiabatic expansion process, and rapid cooling is performed. This is because there was a disadvantage that it was not possible.

Therefore, the present invention solves the above-mentioned problems of the prior art, enables synthesis of a new substance by extremely rapid cooling, and enables creation of a new material having higher performance and higher performance. An object of the present invention is to provide an impact test recovery method.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention solves the above-mentioned problem. In the process of releasing from the compression state generated instantaneously by the shock wave, when the shock wave propagates to the back surface of the sample, the pressure becomes completely zero. The present invention provides a shock sample recovery method characterized by generating a rarefaction wave and rapidly adiabatically expanding the compression state of the sample.

That is, the present invention as described above has been completed based on the results of a detailed study of the mechanism from the generation of an impact pressure to the release process in an impact sample recovery method, which has been hardly understood until now. Then, the compression state of the sample that is instantaneously generated by the impact pressure becomes an instantaneous release process.In this release process, the dilute wave generated in the flying object overtakes the shock wave in the impact pressure sample, and the release process Is started and the pressure is gradually released, and the release process is an adiabatic expansion process, based on the finding that the speed of the adiabatic expansion depends on the generation mechanism of the rarefaction wave and the strength of the rarefaction wave.

The inventor of the present invention has taken the above findings into consideration, for example, by providing a sufficient space behind the sample in the container instead of packing the sample in the collection container without gaps, thereby compressing the sample. They found that the state could be rapidly adiabatically expanded and completed it as an invention.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS That is, in the present invention, for example,
Create a free surface of the sample, such as by providing sufficient space behind the sample in the container, and then cover the container,
Using a sharp dilute wave generated on a free surface, a sample in a shock-compressed state is rapidly adiabatically expanded, that is, the sample is recovered by increasing the speed of the adiabatic expansion process itself.

For this reason, when synthesizing a substance utilizing a high-temperature and high-pressure state instantaneously generated by a shock wave, the rapid quenching effect is increased by increasing the adiabatic expansion rate in the release process, which is usually not possible. Possible material synthesis is also possible as impact synthesis. Of course, the present invention is not limited in its aspect only by providing a sufficient space behind the sample in the container. Any method can be employed as long as a shock wave propagates to the back surface of the sample and a dilute wave with completely zero pressure can be generated and the compressed state of the sample can be rapidly adiabatically expanded.

Hereinafter, examples will be shown, and embodiments of the present invention will be described in more detail.

[0013]

FIG. 1 illustrates an apparatus configuration for the method of the present invention. Specifically, the sample (2) is placed in a collection container (3) for protecting the sample from shock wave destruction,
Further, the collection container (3) is stored in a storage body (1) for storing and protecting the collection container, and the sample (2) is covered with a screw lid (4). On the other hand, the flying object (8) for generating a shock wave is composed of, for example, a servo (6) and a metal flying plate (7), and the flying object (8) is accelerated by, for example, explosive or explosive, etc. Collision with (3). Further, in the present invention, for example, by providing a sufficient gap (5) on the back surface of the sample (2),
When a shock wave propagates to the back surface of a sample, it is possible to generate a rare wave with completely zero pressure.

In the case where the air gap (5) is provided on the back surface of the sample, the collection container (3) is greatly deformed. Therefore, in order to hold the sample without destroying the collection container, the flying object (8) is required. It is desirable that the collision speed in ()) is 1.6 km / sec or less, and the impact pressure is 30 GPa or less.
Of course, such a limitation does not exist when the present invention is realized without providing a gap on the back surface of the sample.

Further, in the present invention, it is desirable to use a highly elastic metal such as SUS304 or platinum as the material of the flying plate and the recovery container. So, in a real example,
Using the above apparatus, for example, a particle size of approximately 1 to 10
A mixture obtained by mixing a micron B—N—C—O-based powder and a copper powder having a particle size of 100 μm in a weight ratio of 1:24 is referred to as S
The container is filled in a US304 collection container (3), and the porosity of the green compact sample (2) is set to 26% by press pressure, and closed by the screw cap (4).

The back of the sample (2) and the screw lid (4)
Is provided with a gap (5) of 2 mm. Collection container (3)
Was inserted into the insertion hole located at the center of the iron storage body (1) to obtain a recovery assembly. Using this as a target, the SUMO attached to the servo (6) and its front surface by gunfire
A projectile (8) comprising a metal flying plate (7) made of S304 is collided to generate a shock wave, and this shock wave is sampled (2).
Let through.

At this time, the collision speed was 1.3 km / s, the impact pressure in the sample was about 11 GPa, and the impact temperature was about 2 GPa.
At 000 ° C., the time change of the pressure when the impact pressure is generated is as illustrated in FIG. 2, and the time change of the temperature is as illustrated in FIG. As shown in FIGS. 2 and 3, there is no essential difference in the compression process between the present invention and the conventional method, but the time until the impact pressure is released to the atmospheric pressure in the release process. In the case of the present invention, while the time from the start of impact compression to the release of pressure is 1.0 μsec, the conventional method takes 1.6 μsec.

Also, the adiabatic release from the start of the rise in the impact temperature to the residual temperature takes 1.0 μsec in the present invention, while 1.6 μsec in the conventional method.
According to the present invention, it is understood that a more rapid release process can be realized, and more complete rapid quenching can be achieved. After the impact compression treatment, for example, the sample (2) is taken out from the collection container (3), immersed in nitric acid to remove copper, and the solution is filtered to collect a precipitate.

When the recovered sample is analyzed by the powder X-ray diffraction method, no new peak is observed in the conventional method, but in the method of the present invention, a new series of peaks appear and it is confirmed that the powder crystals are frozen. . That is, the speed of the adiabatic expansion is increased, and the freezing of the crystal phase is enabled.

[0020]

As described above in detail, the present invention realizes a rapid adiabatic expansion process and enables a material having a metastable phase which cannot be frozen by a conventional method to be subjected to impact synthesis, thereby achieving higher performance and higher performance. Creation of high-performance materials becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of the configuration of an apparatus for the method of the present invention.

FIG. 2 is a relationship diagram showing a pressure change with respect to time when an impact pressure is generated by the method of the present invention and the conventional method.

FIG. 3 is a relationship diagram showing a temperature change with respect to time when an impact pressure is generated by the method of the present invention and the conventional method.

FIG. 4 is a schematic diagram showing an apparatus configuration for a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Storage body 2 Sample 3 Collection container 4 Screw cover 5 Air gap 6 Servo 7 Metal flying plate 8 Flying object

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B01J 3/08 C01B 21/064 C01B 31/06

Claims (4)

(57) [Claims] A sample is placed in a collection container, and the collection container is collected.
Put it in a storage case for protection
Cover, and apply an impact to the bottom of the collection container to remove the sample.
Impact sample recovery method that recovers by compressing only by impact
In the process of releasing from the compression state instantaneously generated by the shock wave generated on the bottom surface of the recovery container , when the shock wave propagates to the back of the sample, a completely zero dilute wave is generated, and the compression state of the sample is rapidly insulated Rapid cooling by expanding
Then, the sample that has been subjected to the compression
A method for recovering an impact sample, comprising recovering the impact sample. 2. A method for generating a completely zero rare wave.
2. The method according to claim 1, further comprising providing a sufficient space on the back surface of the sample. 3. Impact by a flying object at a speed of 1.6 km / sec or less.
And the impact pressure is reduced to 30 GPa or less.
Claims not to destroy the container
2. The method for recovering an impact sample according to 2. 4. Freeze synthesis of powder crystals by shock compression treatment
The impact sample according to claim 1 or 2,
Collection method.