JPH02237634A - Method and device for impact-compressing solid material - Google Patents

Abstract

PURPOSE:To enable mass transfer at a relatively low temp. and to synthesize a dense sintered body with the highly efficient synthesis of a high-pressure-phase material and a chemical reaction by forming >=1 kind of oblique shock waves in a material and impact-compressing the material. CONSTITUTION:A sample 8 is formed to the prescribed initial density, inserted into a sample vessel and fastened by a plug 9. The sample vessel 7 is then inserted into a first momentum trap 10a, and placed them on a second momentum trap 10b. When detonator 1 is then ignited to initiate an explosion lens 2, the plane detonation wave is propagated to a main explosive 3, and the lower flying body 5 is accelerated toward the sample vessel 7 downward and allowed to collide with the upper surface of the sample vessel 7. at a high speed. Consequently, the shock wave is generated on the surfaces obliquely vertical to the collisional direction of the flying body 5, and propagated to the sample 8 through the sample vessel 7. In this case, two kinds of shock waves having the same magnitude in the different directions are generated in the sample vessel 7, and the sample 8 is impact-compressed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for impact compression of solid materials. This article relates to a method and apparatus for impact compression of solid materials, which are used to synthesize materials using a wide range of chemical reactions, including.

(Prior art) By utilizing the shock waves generated by the collision of high-speed projectiles and the detonation shock waves generated by the explosion of explosives,
Solid materials can be impact compressed. The duration of impact compression is generally very short, on the order of 10-' seconds. During this time, a high pressure of several GPa to several tens of GPa and, if necessary, high temperature can be generated in the target material. It is known that when a shock wave with such properties propagates through a solid material, it not only compresses the material, but also changes the physical and chemical properties of the material during and after the shock compression. Furthermore, the degree of this change is even more remarkable in the case of a material with pores. Utilizing such physical and chemical effects associated with impact compression of solid materials, research on impact sintering of difficult-to-sinter materials and the synthesis of unique new materials has been widely conducted. Among them, impact synthesis of diamond is well known, and diamond synthesis using this method has already been industrialized.

Conventional impact compression methods can be roughly divided into the following two types. That is, there are two methods: a direct method in which the detonation wave accompanying the explosion of an explosive is directly transmitted to the material, and an indirect method in which a flying object accelerated by the explosion of an explosive or the like collides with the material to generate a shock wave, which is then transmitted to the material.

The pressure generated in the former direct method is determined by the characteristics of the explosive used and the target material. In impact compression of powder materials,
The sample is generally filled in a metal container, and the explosive is placed on the outside. In this case, the pressure generated in the sample portion can be adjusted by appropriately selecting the material of the sample container.

FIG. 1 shows a longitudinal section of an example of a conventional direct method vertical plane impact compression device. In the figure, 1 is a detonator, 2 is an explosive lens, 3 is a main explosive, 4 is an explosive container, 7 is a sample container, 8 is a sample, 9 is a plug, 10 is a momentum trap, 10a is a first momentum trap, and 10b is a momentum trap. Second
It's a momentum trap. These are common to each drawing described later. After filling a metal sample container 7 with a sample 8 and closing it with a plug 9, this is inserted and set into the hole in the center of the first momentum trap 10a, and this set is placed on the second momentum trap 10b. . The main explosive 4 stored in the explosive container 4 is placed on the sample container 7 and the first momentum trap 10a, and the explosive lens 2 is placed on top of it.

This explosive lens 2 is a pyramid or cone whose bottom surface has the same shape as the horizontal cross section of the main explosive 3. The conical surface is covered with a high-velocity explosive 2a, and the inside is composed of a low-velocity explosive 2b, with a detonator 1 at its apex. It is provided.

When this explosive lens 2 is detonated with detonator 1, high-speed explosive 2
Due to the difference in the burning speed between a and the slow explosive 2b, the time taken for the combustion to reach the bottom surface is the same at each point, so the vertical plane shock wave created by the explosive lens 2 is caused by the main explosive 3 below. The main explosive 3 burns and explodes with its combustion surface horizontal, and the planar detonation shock wave propagates to the sample container 7 below, and further propagates to the sample 8, where the sample 8 is compressed by impact.

In this case, the first and second momentum traps 10a
, 10b absorb the kinetic energy of the sample container 7 in the outer circumferential direction and downward direction of the sample container 7, respectively, to prevent deformation of the sample container 7 and facilitate its recovery.

If a pressure higher than the above-mentioned direct method is required, the latter indirect method may be used.

As shown in the longitudinal section of FIG. 2, this method uses the same explosive lens 2 as the above-mentioned direct method as a planar shock wave generator, and the arrangement of the detonator 1 and main explosive 3 is also the same. Here, the flying object 5 is placed in contact with the lower side of the main explosive 3, and the sample component part consisting of the same sample container 7, the first momentum trap 10, and the second momentum trap 10b as in the above-mentioned direct method, and the above-mentioned flying object are placed in contact with the lower side of the main explosive 3. A spacer 6 is arranged at the outer peripheral portion between the body 5 and the body 5.

In a device with such a configuration, the explosive lens 2 is detonated by the detonator 1 to create a vertical plane shock wave, which causes the main explosive 3 below to explode.
A plane explosion begins. This planar detonation shock wave accelerates the flying object 5 below, and collides with the sample container 7.

This collision generates a vertical plane shock wave within the sample container 7, and this plane shock wave propagates to the sample 8 and shock-compresses the sample 8.

In the above two methods, the surfaces on which the detonation shock wave or shock wave starts to act (the upper surfaces of the sample container 7 and the first momentum trap 10a) are both relative to the flight direction of the projectile 5 or the explosion direction of the main explosive 3. Designed for vertical positioning, especially for material impact compression curves (Ugonio)
He is involved in measurements and research on various physical properties. It is also used in the synthesis of high-pressure phase materials.

Synthesis of diamond by impact compression method was described in 1961 by P. S. DeCarli and J. C. Jamieso
After that, the manufacturing technology was established by DuPont in the United States and is currently being industrialized.

Diamond particles synthesized using static ultra-high pressure are mainly single crystals, but diamond particles synthesized using impact compression are polycrystalline and have excellent grinding ability due to their high grain strength, and can also be obtained as fine crystals. Therefore, it is also suitable for ultra-precision finishing in the field of electronic components, and its range of use is expanding.

However, there are major problems with impact synthetic diamonds that are hindering the expansion of their use and increasing demand. The production cost is more than three times that of diamond powder synthesized by static methods. The cost of statically synthesized diamonds is considered to be reasonable, considering that synthesis of diamonds using static methods requires large and expensive ultra-high pressure generators, and the cost of operating them is also high. By comparison, impact synthetic diamond powder is insanely expensive.

The reason why impact synthetic diamonds are so expensive is that
The reason is that the recovery rate of diamond transferred from graphite by impact compression is too low. Furthermore, the reason for the low conversion rate to diamond observed in this recovered sample is that even if it transforms to diamond during shock compression, most of it returns to the low-pressure phase carbon due to the temperature that remains after the shock wave passes (residual temperature). It is considered.

D. G. Morris recently used a gun to flat impact compress a powder compact of only graphite and a compact of a mixture of metallic cobalt and 22 vol.% graphite to 40 GPa, and investigated the effects of graphite on diamond in each system. Conversion rates were measured and reported. According to this report, the highest conversion rate to diamond in the case of graphite alone is 2.5%, and the highest conversion rate in the case of a mixed system with metallic cobalt also reaches only 14%. Here, we will explain one of the reasons why the latter method, in which graphite powder is dispersed in metal powder, achieves a high conversion rate to diamond.
Another possibility is that even if the impact speed of the projectile remains the same, if a metal with a high impact impedance is mixed, the pressure generated in the graphite part will increase.

In addition, the volumetric shrinkage due to impact compression of graphite is large, and graphite → die. Due to the volume reduction of 36% due to Yamond conversion, the temperature of the graphite part increases considerably during iE impact compression, but when mixed with metal, the metal phase with a lower impact temperature absorbs the heat. One of the reasons mentioned above is that it has the effect of rapidly cooling the graphite part in which diamond is synthesized.

As described above, in the shock synthesis of diamond, when the amount of graphite as a starting material is increased in order to increase the yield, the residual temperature becomes high and the reverse conversion of diamond to the low-pressure phase increases, resulting in a high yield in the recovered material. The recovery rate to diamond decreases. Also, when the amount of graphite dispersed in the metal decreases,
Although the recovery rate of diamond in terms of recovered materials increases, the amount of synthesis per one impact treatment decreases, and a problem remains in either case.

Returning to the essence of the graphite-diamond transition under impact compression, when this transition was first discovered,
This transition between graphite and diamond was thought to be due to collective displacement of atoms over an extremely short distance, that is, martensitic transition. That is, the duration of impact compression is 10-
This is because the duration was as short as 6 seconds, and it was thought that diffusion of atoms would be difficult. However, subsequent detailed research has revealed that this transition to diamond is not diffusion-free, but involves diffusion. In other words, the crystal structure of graphite under impact compression is destroyed once, and the SP of diamond
The mechanism is that a highly disordered structure similar to a glass state is created, consisting of three-hybrid bonds, and then this recrystallizes as diamond.

This mechanism is strongly supported by the results of diamond synthesis by impact compression of glassy carbon and impact compression of non-quality carbon obtained by carbonization of organic matter. Therefore, it can be seen that when trying to synthesize diamond from graphite by impact compression, it is necessary to destroy the crystal structure of graphite and bring it into a state close to non-quality. One way to create such a situation is to
The goal is to raise the temperature of graphite under shock compression, bringing it closer to the liquid phase region of carbon. FIG. 3 is a graph showing the relationship between pressure and temperature of carbon. As can be seen from this figure, the liquidus line of carbon tends to move toward lower temperatures as pressure increases. It is known from the impact compression curve of carbon that a pressure of 35 GPa or higher is required to synthesize diamond. This pressure condition is
Looking at the carbon temperature-pressure correlation diagram shown in the figure, the liquid phase region of carbon corresponds to a high temperature above 3500'Kl. However, with current shock compression technology, attempting to obtain such a high temperature during shock compression will inevitably result in a high residual temperature after the shock wave passes, where there will be more back-conversion of diamond to the low-pressure phase. As a result, the conversion rate in terms of recovered materials decreases.

Such positive and negative effects have also been recognized in the aforementioned report that measured the conversion rate of graphite to diamond. Figure 4 is a diagram showing the relationship between the projectile impact velocity and the conversion rate to diamond, in which the projectile velocity and the conversion rate to diamond are plotted.In this case, since the state of the starting material is the same, the horizontal axis This can also be interpreted as a change in shock temperature. Therefore, this figure shows that the conversion rate increases rapidly up to a certain temperature,
It shows that although a peak is reached, the recovery rate gradually decreases as the temperature increases further. Here, the initial rapid increase in conversion corresponds to the region where the shock temperature approaches or exceeds the liquidus of carbon, and the subsequent decrease in recovery is due to the back conversion of diamond to the low-pressure phase due to the residual temperature. This corresponds to an increase in As described above, in the conventional synthesis of diamond by impact compression, the impact temperature and the subsequent residual temperature cannot be independently controlled, and the conversion rate of graphite to diamond cannot be increased.

Such problems regarding impact temperature and residual temperature are not only present in the case of impact synthesis of diamond but also in the synthesis of high positive phase boron nitride (BN).

In the case of BN, the transition from low-pressure phase BN to high-pressure phase is more difficult to occur than the transition from graphite to diamond, and the reverse conversion easily occurs at residual temperature, so synthesis of high-pressure phase BN is even more difficult. Furthermore, material synthesis and sintering reactions require the movement and diffusion of atoms, but the duration of impact compression is on the order of 10-6 seconds, which is extremely short.

When attempting to produce a dense sintered body under impact compression using synthesis or sintering reactions, the duration of impact compression is 10-6.
Reactions involving the movement of atoms must be completed within seconds. In order to achieve this objective in the conventional shock compression method, it is thought to first increase the shock temperature to facilitate the movement of atoms, similar to the method in the case of diamond synthesis described above. However, given a constant starting material, this requires increasing the impact pressure itself. It is difficult to use this method when the target material contains a high-pressure phase material, and in other cases, increasing the impact pressure may cause significant cracking or residual stress in the resulting material. The problem was that it was easy to do. Furthermore, if the residual temperature is too high, solidification of the liquid phase may occur after the pressure is released, and there is also the problem that pores due to solidification shrinkage are left behind in the recovered material.

(Problems to be achieved by the invention) As mentioned above, in the synthesis of high-pressure phase materials using the conventional FI impact compression method and apparatus for solid materials, and in the synthesis of sintered bodies accompanied by chemical reactions, the above-mentioned problems occur. There were some problems.

The present inventors have enabled mass transfer at relatively low temperatures in impact compression of solid materials, thereby enabling highly efficient synthesis of high-pressure phase materials and synthesis of dense sintered bodies from powders accompanied by chemical reactions. As a result of intensive research into the development of impact compression methods and devices that enable impact compression, we have discovered that, instead of simply impact compression of materials using plane shock waves, we can create one or more types of oblique shock waves in the material. It has been found that by impact compression these above objectives can be achieved.

In other words, the method of impact compression of solid materials attempts to make more active use of the effects of shear stress and shear deformation under impact compression. It is an object of the present invention to provide a method of impact compression suitable for efficient synthesis and sintering accompanied by reaction, and an apparatus for the same.

(Means for Achieving the Object) In order to achieve the above-mentioned object, a solid material is compressed by impact using a shock wave caused by a collision of a high-speed flying object 5 or a detonation shock wave caused by an explosion of an explosive. , a part or all of the surface on which the shock wave or the detonation shock wave starts acting on the sample container 7 loaded with the solid material is perpendicular to the direction of impact of the high-speed projectile 5 or the direction of detonation of the explosive. It is made up of one or more planes, curved surfaces, or a combination of these surfaces in a vertical and oblique positional relationship, and forms one or more types of oblique shock waves in the sample container 7 and the solid material by the action of the shock wave or the detonation shock wave. It performs impact compression while

Further, as a device for performing this impact compression, there is the following 2N type device.

First, a sample container 7 loaded with a solid material of a solid material impact compression device that causes a high-speed flying object 5 to collide with the sample container 7 is parallel to the upper side of the surface where the shock wave starts to be incident upon impact of the high-speed flying object 5. The high-speed flying object 5 is placed with a space in between, and an explosive and detonation means are provided above the high-speed flying object 5, and the explosion of the explosive by the detonation means causes the lower high-speed flying object 5 to move downward. Alternatively, in a device that shock-compresses the solid material by accelerating diagonally downward and colliding with the sample container 7 loaded with the solid material, a part of the surface of the sample container 7 and the flying object 5 on which the shock wave begins to act. Alternatively, the entire surface is composed of one or more planes, curved surfaces, or a combination of these surfaces, which are perpendicularly and obliquely positioned relative to the collision direction of the high-speed flying object 5.

Part 2 is a sample container 7 loaded with a solid material of an impact compression device that detonates an explosive and directly impact compresses the solid material.
an explosive layer is arranged above the surface on which the detonation shock wave caused by the explosion of the explosive is incident, and a detonation means is provided on this explosive layer,
In a device that detonates an explosive layer using this detonation means and shock-compresses a solid material by the accompanying detonation shock wave, a part or all of the surface of the sample container 7 loaded with the solid material on which the detonation shock wave begins to act, It consists of one or more planes, curved surfaces, or a combination of these surfaces, which are vertically and obliquely positioned relative to the explosion direction of the explosive.

(Function) In general, when mechanical crushing, crushing, and other machining processes are applied to a solid material, not only the particles become finer, but also structural defects increase within each particle and strain energy is accumulated. . In the case of a crystalline solid, the crystal structure becomes extremely unstable due to the increase in structural defects and lattice strain, and in some cases, the initial crystal structure may be destroyed and become amorphous.

Energy is released by such amorphization, resulting in a more energetically stable state. As an example of such amorphization, quartz powder is known. Similarly, as a method of releasing strain energy and achieving a stable energy state, rearrangement of atoms or rearrangement as clusters may occur, resulting in a transition to a crystal structure different from the initial one. As such examples, lead oxide (PbO2) and calcium carbonate (CaCOs) are known. or,
Such mechanical crushing and grinding not only increases the chemical reactivity of the treated material, but also significantly accelerates solid phase reactions even during the crushing and grinding. The physical and chemical effects of a series of these mechanical processes on solid materials are particularly called mechanochemical effects, which improve the properties of powder materials,
It is an important means for reforming.

For example, mechanochemical effects can be caused by gentle operation.
This is due to the formation of structurally unstable regions in the crystal structure due to impact, compression, friction between particles, etc. applied to the particles during this process.

In particular, the generation of microscopic shear stress within and between grains due to anisotropic particle compression and intergranular friction, and the resulting deformation, are thought to have a significant impact on mechanochemical effects. It will be done. There are many known examples of solid phase reactions that occur during rough operations, but this example dramatically shows how important shear stress and the accompanying deformation are in such solid phase reactions. There is also. For example, using a mixed powder of aluminum (AI) and copper oxide (Cub) as a starting material, this was pressurized using a uniaxial pressurizer, and the manner in which oxidation and reduction reactions occurred there was investigated. As a result, if the thickness of the cylindrical sample is much larger than the sample diameter, i.e.
The above expected reaction did not occur under conditions where it was difficult for shear stress to occur within the sample.

On the other hand, we have found that when the thickness of the sample is smaller than the sample diameter, that is, under conditions where shear stress is likely to occur, the solid phase reaction described above proceeds explosively. This result indicates that the reaction here is extremely sensitive to the shear stress and deformation occurring within the sample, and that this reaction was stimulated by shear deformation.

It has also been reported that the reaction therein was independent of temperature and depended only on the pressure of uniaxial pressing, that is, the shear stress and the degree of deformation. This shows that shear stress and deformation have more important effects than temperature on such solid phase reactions.

It is known that the mechanochemical phenomenon described above occurs even when impact compression is performed on solid materials, especially powders, produced by conventional methods. Impact compression is characterized in that the level of stress applied is higher than in the mechanical crushing and grinding described above, and the rate of stress application is also extremely fast. In impact compression, a solid material simply behaves as an elastic body at low pressure levels and as a plastic body at high pressure levels. Specifically, the passage of the shock wave causes the solid to instantaneously enter a state of uniaxial compression, resulting in high shear stress occurring in an oblique direction perpendicular to the front of the shock wave.

When this level reaches the limit of shear stress inherent in the material, plastic deformation occurs. At this time, the stress in the direction of shock wave propagation that marks the boundary between elastic behavior and plastic behavior is called the Ugoniot limit. For impact compression, the Ugonio limit is known to be 2-3 times higher than for static uniaxial compression. Therefore, in shock compression, the shear process with high stress levels causes crystal lattice distortion and an abnormal increase in defects in the solid.

However, in the case of vertical shock waves, the shear deformation is highly constrained due to uniaxial compression. This macroscopic constraint does not change even with powder. However, in the case of powder, this constraint is broken at the particle level as long as there are pores. Therefore, large shear changes occur locally in the particles. This also has a significant impact on the deterioration of crystalline solids and the transition to other crystal structures.

An example of the former is quartz powder (Si02), and when crystalline Si02 is subjected to impact compression treatment from a low level,
The process of gradual amorphization as the pressure increases can be seen. Further, as an example of the latter, there is a transition from BN having a graphite-like structure (hereinafter referred to as g-BN) in the low pressure phase to wurtzite type BN (hereinafter referred to as 1BN) in the high pressure phase. This transition is a martensitic type transition that is achieved by a slight displacement of a series of atomic layers in the crystal structure of g-BN, and this type of transition is achieved by the shear stress acting under impact compression. Therefore, g-BN to wBN due to impact compression
The conversion rate is relatively high. Such transition to other phases and deterioration of quality can be avoided by impact compression method, if you want to make crystalline solid material amorphous without quenching it from high temperature.
This suggests that it is better to increase the amount of shear stress generated under impact compression, that is, the amount of shear strain.

In materials such as ceramics, which have low thermal conductivity, in areas where shear deformation occurs as described above, the sliding deformation there is locally concentrated and high temperatures occur.

Therefore, in areas where shear deformation is concentrated under impact compression, the crystalline solid is likely to deteriorate. Furthermore, the temperature here is higher than the surrounding area, and the movement of atoms there is less constrained, which is favorable for synthetic reactions involving diffusion of atoms.

Shear stress and its associated changes in powders are very complex, but the effects are the same as in solids.

(Example) When solid objects collide obliquely, a longitudinal shock wave and a transverse shock wave are generated on both sides. The shock wave obtained by such a method is an example of what is called an oblique shock wave. Compression using oblique shock waves has the advantage that longitudinal wave components and transverse wave components of the elastic properties of solids can be analyzed independently, and this property can be used to study the equation of state of solids and to conduct research under high pressure. It has been mainly used for measurement experiments such as physical property measurements. Methods for generating oblique shock waves include colliding solid bodies in parallel and oblique directions, using two-dimensional and three-dimensional detonation shock waves, colliding planes at a certain angle, and propagating through anisotropic crystals. A method using plane shock waves has been proposed. However, the conventional purpose of using oblique shock waves was for measurement experiments, and therefore the means of generating them was limited to the shock gun method using light gas or gunpowder. There is no example of using the explosive power of explosives to generate diagonal shock waves and using them for material synthesis.

FIG. 5 is a schematic diagram of an oblique shock wave when solid bodies are obliquely collided with each other at a collision speed of 2V, and is a two-dimensional schematic diagram showing the state immediately after the oblique shock wave having a stress exceeding the elastic limit is generated.

Simultaneously with the collision, a longitudinal shock wave in a direction perpendicular to the collision surface and a transverse shock wave parallel to the collision surface begin to propagate from the collision surface into both materials, as shown in FIG. Let α be the pre-angle of the collision surface from a plane perpendicular to the direction of impact of the projectile, and assuming that there is no slippage on the collision surface, the particle velocity Vl due to longitudinal waves and transverse waves. ．． v2 are Vcos α and Vs, respectively
It is given by irα. For example, if the same iron projectile collides with an iron block at a deviation angle α from the vertical of 15 degrees and a collision speed of 2 km/s, and there is no slippage on the collision surface, then this will occur between the iron block and the iron projectile. The particle velocities in longitudinal shock waves and transverse shock waves are 0.95 km/s and 0.25 km, respectively.
/s. For simple vertical plane impact compression (α=0)
Then, under the same conditions, the particle moves only in the direction perpendicular to the collision surface.
It moves at an acceleration of km/s. However, in the impact compression using oblique shock waves used in the impact compression method according to the present invention,
It can be seen that the particle velocity is considerably high not only in the direction perpendicular to the collision surface but also in the plane parallel to the collision surface, making it possible to transfer mass at a much higher speed and efficiency than with a simple vertical plane shock wave. Furthermore, such high-speed mass transfer here is not caused by excitation due to heat as seen in conventional chemical reaction processes, and is characterized in that it is almost independent of the temperature of the system. This effect enables high-speed mass transfer at relatively low temperatures, providing conditions suitable for high-pressure phase synthesis, such as diamond synthesis.

The propagation of oblique shock waves, which has such an important effect, can exist as long as the material remains rigid or viscous, even if the stress of the longitudinal shock wave reaches the plastic region exceeding the elastic limit.

In conventional compression by vertical plane shock waves, particles after passing through the shock wave front are accelerated in one direction at high speed, causing high-speed mass transfer in that direction, but because this flow is uniaxial, a high shear force acts, High-speed shear deformation occurs in a direction perpendicular to and oblique to the direction of shock wave propagation. As described above, this facilitates deterioration of quality and transition to a different crystal structure.

In the case of compression by oblique shock waves used in the impact compression method according to the present invention, this shear stress and the resulting deformation become even more significant. The material through which the oblique shock wave has passed is accelerated and compressed at high speed in the direction perpendicular to the collision surface, and at times is also accelerated at high speed in the direction perpendicular to the direction of compression, which corresponds to the shear plane. become.

For example, in the above example, if the deviation angle of the collision surface from the plane perpendicular to the collision direction is 15 degrees, the particle velocity in the direction perpendicular to the collision surface is 0.95 km/s, and the pressure is approximately This corresponds to 40 GPa. On the other hand, if slippage on the collision surface is ignored, the particle velocity in the shear direction is 0.25 km/s, and the stress in this direction increases to the elastic limit in that direction. This corresponds to applying an extremely large shear strain to the material in a uniaxially pressurized state of up to 40 GPa in the direction of instantaneous shearing. The effects of shear stress and shear deformation on the mechanochemistry of powder materials are as described above, and the material compressed by oblique shock waves is not only in a significantly activated state, but also the mass transfer there is extremely fast. I understand that it will become.

Furthermore, as described above, high temperatures occur in areas where shear stress acts and shear deformation is concentrated.

Therefore, in impact compression of a material using oblique shock waves, the degree of deformation due to the action of shear stress increases and the area where shear deformation concentrates also increases compared to the case of vertical plane shock waves. In these regions, crystalline materials should easily deteriorate in quality. Furthermore, the temperature in such a region will be higher than the surrounding area, and the restrictions on the movement of atoms there will be further removed, creating many suitable locations for synthetic reactions and sintering reactions that involve atomic diffusion. . As mentioned above, in the synthesis of diamond by impact compression, due to the nature of its transition, diamond crystal nuclei must be generated and grown from a state in which the crystal structure of graphite, the starting material, has been destroyed. To make such a synthesis process possible and low enough to avoid inversion after passing the shock wave, a non-quality structure of graphite can be easily obtained at a relatively low temperature and a high-speed A process capable of mass transfer was needed.

It can be seen that the process obtained by shock compression of materials using the above-mentioned oblique shock waves is exactly such a process.

The temperature in the region where significant shear deformation occurs instantaneously reaches a fairly high temperature, but because the surrounding temperature is low, the area is rapidly cooled down and has little negative impact on the inversion of the diamond.

In the shock compression of a solid material using an oblique shock wave according to the present invention, in a sample container loaded with the material, part or all of the surface on which the shock wave or detonation shock wave starts to act is in the direction of the impact of the projectile or the detonation direction of the explosive. It consists of one or more planes, curved surfaces, or composite surfaces thereof (hereinafter referred to as composite surfaces, etc.) that are perpendicular to or oblique to the surface, and the range of the angle α of deviation from the perpendicular surface is As shown in the oblique collision range diagram of FIG. 6, the vertical collision surface is 5 degrees or more and less than 60 degrees left and right, preferably 7.5 degrees or more and 45 degrees or less. When the deviation angle is less than 5°, the particle velocity of the shock wave component in the shear direction does not reach even 10% of the particle velocity of the perpendicular component, so the effects of shear stress and deformation are too small, and the effects of the present invention cannot be exhibited. .

On the other hand, when the deviation angle α is 60" or more, the particle velocity in the component in the shear direction becomes too large, and the sliding of the collision surface and the deformation of the sample container and sample become significant. This results in stable impact compression using oblique shock waves. The effect of compression using an oblique shock wave can be made significant, in part, by increasing the deviation angle α within the preferable range.

Furthermore, it is also effective to increase the number of composite surfaces in the above-mentioned vertical and diagonal positional relationship. However, in this case, if too many such composite surfaces are provided, the interference between oblique shock waves cannot be ignored, and the original effect cannot be expected, which is not preferable. Furthermore, the size of these composite surfaces provided on the sample container must be at least 11n2 or more in order to exhibit the effect.

Next, an apparatus for carrying out the impact compression method according to the present invention will be explained.

FIG. 7 shows one embodiment of the indirect method, and the reference numerals in the figure are the same as in the case of FIG. 1 described above. Here, the explosive lens 2 will be additionally explained. The explosive lens 2 has a conical or pyramidal bottom with the same shape as the horizontal cross section of the main explosive 3,
Each conical surface is covered with a high-velocity explosive 2a, and the internal vertebral bodies are filled with a low-velocity explosive 2b.

In this embodiment, the bottom surface of the explosive lens 2, the main explosive 3
The horizontal cross section of the flying object 5 has the same shape as the horizontal cross section of the sample container 7, and has a structure in which it does not cross the first momentum truss 10a as in the conventional example shown in FIG.

The biggest feature of the embodiment of the present invention is that composite surfaces, etc. are formed on the lower surface of the flying object 5 and the upper surface of the sample container 7, and the protruding directions of each composite surface, etc. are reversed, so that when they make contact, the entire surface is are constructed so that they are in complete contact with each other at the same time.

That is, as shown in FIG. 8, the upper surface of the sample container 7 (the surface that the flying object 5 collides with) has ridges and valleys that are concentric circles, as shown in the cross-sectional views of FIG. 8 (a) and (c). Several surfaces are provided that are perpendicular to and diagonal to the projectile impact direction.

On the other hand, the surface of the flying object 5 facing the main explosive 3 is a flat surface, but the surface facing the sample container 7 has the same shape as the upper surface of the sample container 7 in the opposite direction of protrusion.

The one shown in Figure 8 (opening) has the above-mentioned ridges and valleys parallel to each other, and the cross-sectional view perpendicular to these parallel lines is (c).
It is consistent with the figure.

Next, the operation of this device will be explained.

First, after molding the sample 8 to a predetermined initial density, it is inserted into the sample container 7 and tightened with a plug 9 so that there is no space around the sample 8.

The sample container 7 containing the sample 8 in this manner is inserted into the first momentum trap 10a, and placed on the second momentum trap 10b.

Next, the detonator 1 is ignited to detonate the explosive lens 2.

Here, when the angle of the apex of the conical shape of the explosive lens 2 is θ, the detonation speed of the high-speed explosive 2a is vh, and the detonation speed of the low-velocity explosive 2b is Vl, it is made so that Cos (θ/2) = Vl/Vh. This allows the detonation at the apex to be replaced by a planar detonation wave during the detonation from there to the bottom.

In this way, the plane detonation wave formed by the explosive lens 2 is propagated to the main explosive 3 below, and the detonation wave of the main explosive 3 accelerates the projectile 5 below towards the sample container 7 below. , collides with the upper surface of the sample container 7 at high speed. As a result of this collision, oblique shock waves are generated on each surface that is perpendicular to and oblique to the collision direction of the flying object 5, and this is propagated to the sample 8 through the sample container 7. In this case, when viewed in the cross section of Fig. 7, two types of oblique shocks of the same magnitude but different directions occur on the sample container 7 and propagate to the sample 8, causing the sample 8 to be compressed by the shock wave. be done.

First and second momentum traps 10a, 10
b is for facilitating recovery of the sample 8 after impact compression, and in particular, the first momentum trap 10a is for the purpose of absorbing the kinetic energy in the outer circumferential direction of the sample container 7, and the second momentum trap 10b is for absorbing the kinetic energy in the downward direction. Preferably, it is made of iron, which has a large mass and high strength. It is also preferable that the sample container 7 and the plug 9 be made of a metal as strong as possible. Practically speaking, high-tensile steel such as stainless steel is preferable. The thicker the wall thickness of the sample container 7 is, the better from the perspective of preventing damage to the sample container 7. Here, when the sample container 7 is made of stainless steel, the wall thickness in the outer circumferential direction is 2 to 1 mm.
0 + n is sufficient, and the thickness of the top surface is 21 even in the thin part.
1 or more is required, preferably 4 to 10 fl.

In addition, the plug 9 is to prevent the impact-compressed sample 8 from blowing out downward, and when the processing pressure is low, it is not necessary to use a screw-in type, but when the pressure is high, the plug 9 is Since the sample container 7 can easily come off, it is preferable to connect it with the sample container 7 using screws.

In addition, collection of the sample container 7 can also be facilitated by making the plug 9 longer. After the high-pressure shock wave passes through,
This is because the rarefied wave reflected from the bottom surface is attenuated inside the long brag 9 and hardly reaches the sample 8.

Further, the flying object 5 is preferably made of a flat metal plate with high strength, and in practice, an iron plate, a stainless steel plate, or a copper plate is used. Its thickness, which determines the duration of impact compression, requires that even the thinnest part of the projectile 5 in the device of the method according to the invention be at least 1 liter, preferably at least 2 liters. The spacer 6 can be made of metal rod, wood, plastic, cardboard, etc. The explosive container 4 is of a type that is used when an amorphous explosive such as ANFO or granular dynamite is used as the main explosive 3, and is made of plastic,
It can be made from wood, cardboard, etc.

FIGS. 9(a), 9(c), and 9(ii) are longitudinal cross-sectional views of the flying object 5, sample container 7, sample 8, and plug 9 in reloading that can be used to implement the impact compression method according to the present invention. . When these devices are used, the shape of the upper surface of the sample container 7 is composed of a composite surface or the like, as in the above example. However, in the case shown in (2), the sample container 7 is cylindrical and has a structure in which the flying object 5 directly collides with the sample 8.

The example shown in FIG. 9(a) is a method suitable for a case where the sample 8 is not uniform, two different samples 8, 8 are loaded concentrically, and it is desired to impact-compress each sample under different conditions.

The example in the same figure (opening) is a case where the cross-sectional shape is not a sharp square but a gentle curve, and the intensity and shape of the oblique shock wave can change continuously, making it useful for synthesizing sintered bodies using reactions, etc. This is a suitable method.

The example shown in FIG. 3(c) is a method suitable for the same application as in (a) above.

The example in (2) of the same figure is an example of a method in which the flying object 5 directly collides with the sample 8, and the shape of the collision surface is as shown in (a), (mouth), and (c) above.
It is easy to change it depending on the purpose.

FIG. 10 shows another embodiment using the indirect method using the flying object 5, as in FIG. ) is a plan view of the detonator part. This apparatus is suitable for performing shock compression treatment on the elongated sample 8 using oblique shock waves.

First, the sample container 7 is filled with the sample 8, fixed with the plug 9, and then placed on the second momentum trap 10b. It has a shape as shown in the cross-sectional view (mouth) of the sample container 7 in the direction of projectile collision, and the ridges of the convex portions of the upper surface are arranged parallel to each other.

On the other hand, as in the previous example, the surface of the flying object 5 facing the sample container 7 has a three-dimensional shape that is a copy of the top surface (impact surface) of the sample container 7, and the main explosive 3 on the opposite side is placed thereon. The upper surface is flat.

At one end so that it is almost flush with the main explosive layer (c)
As shown in the figure, a detonator for line detonation is installed.

This detonator has a metal plate 11 on the main explosive 3 side, a sheet explosive 12 on the opposite side, and a detonator 1 on one end of these.
The other end is provided at an opening angle θ from one end of the main explosive 3.

Here, the detonation speed of the sheet explosive 12 is I/d, and the speed at which the inner metal plate 11 is blown away by the explosion is Vm.
Then, θ is set so that Vm/Vd = tanθ.

When the sheet-like explosive 12 is detonated by the detonator 1 in this configuration, the metal plate 11 inside is blown off and simultaneously collides with one end of the main explosive 3, causing line detonation there. Due to this linear detonation, the linear explosion of the main explosive 3 propagates from right to left in the figure, and the lower flying object 5 sequentially collides with the lower sample container 7 from the detonator side as the main explosive 3 explodes. , an oblique shock wave is generated in the sample container 7, which propagates to the sample 8 and shock-compresses the sample 8 with the oblique shock wave.

FIG. 12 shows a device whose entire structure is cylindrical, and (A) is a longitudinal sectional view, and (B) is a sectional view taken along line B-8 in FIG. This device has a cylindrical sample container 7 containing a sample 8 in the center, and the inner surface of this sample container 7 is a cylindrical surface.
The outer surface is composed of an annular continuous conical surface in which upward and downward conical surfaces are continuous, and the upper and lower ends are plugs 9, 9.
is blocked by. A cylindrical flying object 5, whose upper and lower ends are held by the upper and lower plugs 9, is held concentrically at a constant distance from the outer surface (outer peripheral surface) of the sample container 7. The inner surface (inner circumferential surface) of this flying object 5 is a surface having a shape that is a transfer of the outer circumferential surface of the sample container 7, and the outer circumferential surface is a cylindrical surface. In addition, if necessary, instead of one cylinder, one
It goes without saying that a cylinder may be vertically divided into a plurality of pieces, each piece being brought together and arranged in the original cylindrical shape.

The central member composed of the above-mentioned members, that is, the sample 8, the sample container 7, the flying object 5, and the upper and lower plugs 9, is arranged along the center line of the explosive container 4 whose lower end is closed. The main explosive 3 is filled around the main explosive 3, the upper end is closed with a lid 13, and the detonator 1 is placed in the center of the lid 13.

Therefore, in this device, the first and second momentum traps 10a, 10b and the explosive lens 2 are omitted.

FIG. 13 is a modification of FIG. 7, in which the upper surface of the sample container 7 is a curved surface with a concave center, and the projectile 5 is a flat plate, with the main material filled in the explosive container 4 on the upper side. An explosive charge 3 is arranged, a detonator 1 is arranged directly at the center of the upper surface of the main explosive charge 3, and an explosive lens 2 is omitted. Note that the first and second momentum traps 10a and 10b are the same as those in FIG. 7.

In the above-mentioned explosion situation of the main explosive 3, the deflagration surface exploded by the detonator 1 advances in a spherical shape with the detonator 1 as the center, so the projectile 5 becomes curved due to the time difference in reaching the projectile 5. and collides with the sample container 7. In this case, the curvature of the projectile 5 from its original plane until it collides with the sample container 7 changes depending on the shape of the main explosive 3, its deflagration speed, etc., but this curvature can be measured in advance. Therefore, based on this measurement value, the upper surface of the sample container 7 is formed so as to have the same curved surface.

Each of the above embodiments is an impact compression method using an indirect method in which a parallel space is provided between the sample container 7 and the flying object 5.
The figure shows an example of the direct method. Filled with sample 8, first and second momentum traps 10a, 1
Using 0b is the same as the above-mentioned indirect method, but the upper surface of the sample container 7 and the lower surface of the main explosive 3 are in direct contact as shown in FIG.

In this case, the upper surface of the sample container 7 may have a shape in which the ridges of the convex triangular portion are concentric circles or a shape in which the ridges are parallel to each other.

Next, the operation of using this device will be explained.

Filling the sample container 7 with the sample 8 and feeding it into the first and second momentum traps 10a and 10b is the same as in the indirect method described above.

Next, the main explosive 3 is filled into the explosive container 4, and this is transferred to the sample container 7.
Place the explosive lens 2 and detonator 1 on top of it.

In the case of the apparatus shown in FIGS. 12 and 13, the explosive lens 2 is not used, and the detonator 1 is placed in direct contact with the main explosive 3.

When performing shock compression, the explosive lens 2 is detonated by the detonator 1, and the plane shock wave formed there is propagated to the main explosive 3 below, causing the main explosive 3 to explode in a plane from the top to the bottom. A roaring wave is propagated to the sample container 7 below. Here, on the surface of the upper surface of the sample container 7 that is perpendicular to and oblique to the detonation direction of the main explosive 3, the plane detonation wave first enters the sample container 7 as an oblique shock wave, and then The wave propagates to the sample 8, and the sample 8 is subjected to impact compression by the oblique shock wave.

This direct method can also utilize the sample container shapes shown in FIG.

As shown in FIG. 11, the method that does not use the flying object 5 has a simple structure and is advantageous, but this method has the disadvantage that the pressure that can be generated is low as described above. Therefore, it is necessary to use either the direct method or the indirect method depending on the required pressure level.

(See Experimental Example 1 - Figure 7) Graphite powder with an average particle size of 10 μm and copper powder with a particle size of 325 mesh or less were mixed at a volume ratio of 1:1 to obtain a mixed powder for diamond synthesis. This mixed powder was subjected to impact compression using the apparatus shown in FIG. 7 using a device 1 whose top view of the sample container 7 was as shown in FIG. 8(a). The sample container 7 and the plug 9 in FIG. 7 are made of iron, and the cross section of the concentric convex portion of the upper surface of the sample container 7 facing the flying object 5 is triangular, and the apex angle of this triangle is an isosceles triangle of 140°. And so. In other words, the angle of deviation from the plane perpendicular to the collision direction of the flying object 5 is 20
” Each side was set up so that

In addition, the outer diameter of the convex portion with a triangular cross section is 21 m, which is the same as the outer diameter of sample 8, the length of the base of these triangles is 1/3 of that, 71 m, and the height is 1.3 + m. be. The outer diameter of the sample container 7 is 40 mm, the height is 30 mm, and the space (sample chamber) in which the sample 8 is placed is 21 m in diameter.
m, the height was 5 dragons, and the length of Brag 9 was 20 cranes.

The above mixed powder is placed in the sample chamber of this sample container 7 at an initial density of 6.
It was filled to a concentration of 5% and fixed by tightening with a screw-in plug 9. The sample container 7 thus constructed has an outer diameter of 1
00 dragon, inserted into the first iron momentum trap 10a with a height of 30 m and a hole for a sample container in the center, and then placed on the second iron momentum trap 10b with an outer diameter of 100 mm and a height of 30 m. placed.

The flying object 5 is made of iron, and the surface facing the sample container 7 is lathed into a shape that transfers the three-dimensional shape of the top surface of the sample container 7.
The opposite side is a flat surface. The outer diameter of this flying object 5 was 40 m, and the thickness was 4.0 mm at the unprocessed part and 2.7*n at the thinnest part.

As shown in FIG. 7, this iron flying object 5 was installed using a 5 fl square piece of balsa wood as a spacer 6 with a space of 15 mm between it and the sample container 7 below.

Furthermore, an explosive container 4 made of vinyl chloride is placed on top of this flying object 5.
The main explosive charge 3 was loaded on the tank. As this main explosive 3, the explosion speed is 7. 2km8 Jubon data sheet C
-6 was used to give a thickness of 66MX.

Explosive container 4 has an inner diameter of 130 N, an outer diameter of 140 N, and a height of 66 m.
I used the one from

Data sheet C- as high velocity explosive 2a on top of main explosive 3
2 was mounted with an explosive lens 2 using an emulsion explosive as a low-velocity explosive 2b, and a detonator 1 for detonation was further attached thereon. The outer diameter of the bottom surface of this explosive lens 2 is made to match the outer diameter of the explosive container 4 containing the main explosive 3.

After assembling the device for shock compression as described above, the explosive lens 2 is detonated by the detonator 1 to create a plane shock wave.
The action causes a planar explosion of the lower main explosive 3, thereby detonating the lower projectile 5 by about 1.5 mm in this case. It was accelerated to 8 km/s and collided with the sample container 7 below.

After the impact treatment, the sample container 7 had discoloration on the outside, but was recovered without major deformation. Sample 8 was taken out from the collected sample container 7 by cutting, and first, copper was removed by acid treatment, then graphite was oxidized and removed using lead oxide, and the conversion rate from graphite to diamond was examined. As a result, the conversion rate to diamond by this method was about 68%.

In addition, for comparison with the apparatus-based method of this experiment, using the same mixed powder as in the above experimental example, impact treatment using a conventional planar shock wave was attempted. In this case, the triangular convex portion at the top of the sample container 7 shown in FIG. 7 was not provided, and the flying object 5 was made of an iron plate with a thickness of 3 mm. Other conditions such as the materials, shapes, and dimensions of the device components, as well as the explosives used, were the same as in the above experimental example.

Under these conditions, the collision speed of the flying object 5 with the sample container 7 is 2
．． The speed was 0km/s. After the impact treatment, Sample 8 was recovered in the same manner as above and the conversion rate to diamond was measured.

As a result, the conversion rate when using this simple plane shock wave reached only 13%.

(See Experimental Examples 2 to 7) In Experimental Example 1, the cross-sectional shape of the surface of the sample container 7 facing the flying object 5 was a triangular convex shape, but in this experimental example, as shown in FIG. It has a curved surface shape as shown in Figure 8 (
They are parallel convex portions as shown in Figure 1). The lower surface of the flying object 5 is also a three-dimensional surface with a shape corresponding to this. Other details were the same as in Experimental Example 1 above.

In this case, the width of each peak on the upper surface of the sample container 7 is 7+n, which is the same as in Experimental Example 1, and the curvature of the ridges and valleys is approximately 5.5.
It was made into a fin.

Using this device, the same mixed sample as in Experimental Example 1 was used, and the sample container 7 was filled with the mixed sample so that the initial density was 65%, and the mixture was detonated and subjected to impact treatment in the same manner as in Experimental Example 1.

After impact treatment, sample 8 was collected in a similar manner and the conversion rate was measured. As a result, the conversion rate when this device was used was 62%, which was not much different from the device of Experimental Example 1.

(See Experimental Example 3 - Figure 11) BN (gBN) powder with a structure similar to graphite with an average particle size of 5 μm and iron powder with a particle size of 325 mesh or less were blended at a volume ratio of 1:1 to form a mixed powder. The impact compression device is shown in FIG. 11, and does not use a flying object 5, and has the main explosive 3 in direct contact with the top surface of the sample container 7.Other than this, the device is the same as shown in FIG. is the same as

In the case of this experimental example, the sample container 7 was filled with the above-mentioned mixed powder to an initial density of 70%, and was fixed by tightening with a screw-in plug 9.

In this state, similarly to Experimental Example 1, the explosive lens 2 is detonated with the detonator 1 to form a plane shock wave, and this plane shock wave is propagated to the main explosive 3 below. This propagation causes the main explosive 3 to detonate in a plane, and the plane detonation wave is propagated to the sample container 7 below, and the sample 8 is subjected to impact treatment.

After the impact treatment, the sample container 7 was recovered, but there was almost no deformation. Sample 8 was collected from the collected sample container 7 in the same manner as in Experimental Example 1, and after dissolving iron with acid, gBN was removed by treatment with an alkaline solution at 400°C to obtain high-pressure phase BN. At this time, the conversion rate to the high pressure phase reached approximately 87%. Furthermore, as a result of X-ray diffraction, the high-pressure phase here is wurtzite-type BN (w
BN) and cubic BN (cBN), but 2
Because the diffraction lines of the two phases overlap, the proportions of the two phases cannot be accurately determined.

In this case as well, for comparison, an experiment was conducted in which the upper surface of the sample container 7 had a flat surface without a triangular convex portion.

In this case, the same sample 8 as above is used, and the sample container 7
The filling rate was also set at <70%. The materials, shapes, and dimensions of the other device components and the type and amount of explosives used were the same as in the above experimental example. Regarding the sample obtained by this method, the conversion rate from gBN to the high pressure phase was also investigated using the same procedure as the above method. As a result, the conversion rate in this case was as low as 28%. Furthermore, when the finally obtained high-pressure phase powder was subjected to X-ray diffraction measurement, this phase consisted only of wBN, and no cBN was observed. As a result, this conflict is thought to indicate that it was difficult to convert gBN to cBN, which requires atomic diffusion, using this simple planar fi-wave attack method.

(See Experimental Example 4 - Figure 10) Titanium (Ti) powder with a particle size of 10 μm or less and amorphous boron (B) powder with a particle size of 1 μm or less were mixed at a molar ratio of 1:20 to obtain a mixed powder. This mixed powder was subjected to impact compression treatment using an impact compression apparatus shown in FIG.

The sample container 7 in Figure 10 (a) is 50 cranes x 500 cranes x 40
It is the size of a crane, made of stainless steel, and has a triangular convex cross section as shown in the same figure (mouth). In this case, an isosceles triangle shape with an apex angle of 120' was used. In other words, the angle of deviation from the plane perpendicular to the collision direction of the flying object 5 is 30 degrees. Further, the length of the base of this triangle was set to 10 m, which is 173 of the width of the wipe 8 of 30 m. The height of each triangle at this time is approximately 2.8 cranes. In this case, the triangular convex portions are processed so that they are parallel to each other when viewed from a top view. The above mixed powder is placed in the sample container 7 having such a top surface shape at an initial density of about 60.
%, and a fitting type plug 9 was fitted to fix the sample 8.

The space in the sample container 7 that contained the sample 8 had a width of 30 mm, a length of 400 mm, and a height of 5 ml. Next, fill the sample container 7 with the sample 8 and fix it with the plug 9.
It was placed on a second iron momentum trap 10b with a length of 500 liters and a height of 40 liters.

The flying object 5 was made of iron, and its surface facing the sample container 7 was processed with a milling machine so that it had a three-dimensional shape that copied the shape of the top surface of the sample container 7. In this case, an iron plate having a thickness of 4 l was processed and produced, but the thickness of the minimum thickness portion after processing was approximately 1.2+n. The shape of this flying object 5 was 50 m wide and 500 m long in accordance with the shape of the sample container 7 below.

The main explosive 3 was placed on the upper plane of the flying plate 5. As this main explosive 3, data sheet C~6 manufactured by Jupon Co.
was used so as to have a thickness of 48 wm. A detonator for wire detonation was provided at one end of the main explosive 3 as shown in FIG. This detonator is 2cm thick, 10cm wide, and about 5cm long.
A 0 mm aluminum plate (metal plate 11) with data sheet C-2 (sheet explosive 12) pasted on the outside was used. This metal plate 11 was oriented toward the main explosive 3 and one end thereof was fixed to the main explosive 3 as shown in FIG. 10(c). In this case, the main explosive 3 and the detonator are at an angle θ on the plane.
The angle was approximately 11°, and detonator 1 was attached to the tip.

In the impact treatment, first, the sheet explosive 12 is detonated by the detonator 1, and the inner metal plate 11 is blown towards the main explosive 3 by the detonation wave, and simultaneously collides with one side of the main explosive 3, causing the main explosive 3 to explode. resulting in a linear explosion.

Due to this linear explosion, the lower flying object 5 is blown downward from the detonator side and sequentially collides with the sample container 7 to perform impact treatment.

After the impact treatment, the sample container 7 was collected and milled to take out the sample 8. Sample 8 was recovered in one piece and was a dense sintered body. Polish a part of this sample and
When a line diffraction measurement was performed, this sintered body was composed only of TiB2, and no unreacted TI%B was detected. Moreover, the average hardness of this sintered body was 2600 kg/mm''.

On the other hand, for comparison, an impact treatment using a plane shock wave was attempted using the same mixed powder as in the above experiment.

In this case, the upper surface of the sample container 7 shown in FIG. 10 was made flat, and the lower surface of the flying object 5 was also made flat, using an iron plate with a thickness of 3 fl.

Other conditions, ie, the materials, shapes, and dimensions of the device components and the type and amount of explosives used, were the same as in the above experimental example. As a result, the expected reaction between Ti and B did not occur in this sample, and the powder was densified but not sintered.

(Refer to Experimental Example 5 - FIG. 12) As shown in FIG. 12, a sample 8 is filled into a cylindrical sample container 7, and the top and bottom are closed with plugs 9, 9.

In this case, Sample 8 had the same composition of ingredients as in Experimental Example 1 and was packed at the same initial density.

The flying objects 5 are arranged concentrically at a certain distance around the outer periphery of the sample container 7 filled with the sample 8 in this manner. In this case, the flying object 5 may be a single cylindrical object, or may be a plurality of pieces obtained by vertically dividing this cylindrical object and arranged in the original cylindrical shape. A central member consisting of the sample 8, sample container 7, flying object 5, and plugs 9 is placed on the center line of the explosive container 4, the main explosive 3 is filled around the central member, and the lid is closed.
The detonator 1 is attached to the center of the lid 13.

When the main explosive 3 is detonated by the detonator l in this state, the main explosive 3 deflagrates sequentially from the upper side to the lower side, causing the flying object 5 to collide with the sample container 7. As a result, vertical and oblique shock waves are generated within the sample container 7 and the sample 8 due to the continuous conical surface of the outer peripheral surface of the sample container 7, causing the sample 8 to undergo a conversion reaction into diamond.

Since the results are almost the same numerical values as in Experimental Example 1, they will be omitted.

(See Experimental Example 6 - Figure 13) In this experimental example, the sample 8 is filled into the sample container 7 and attached to the first and second momentum traps 10a and 10b in the same way as in the case of Experimental Example 1, Figure 7. .

Further, a flat flying object 5 is placed on top of the sample container 7 with a spacer 6 between the two, and the main explosive 3 filled in the explosive container 4 is placed on top of the flying object 5 in contact with it. The explosive lens 2 is not used for this main explosive 3, and the detonator 1 is attached directly to the center.

After arranging it in this way, when the main explosive 3 is detonated by the detonator 1, the main explosive starts to deflagrate from the detonator 1, so it deflagrates in an almost spherical shape, and the planar projectile 5 is brought to its center. The particles are blown outward from the point and downward in a circular pattern, forming a spherical curved surface and colliding with the upper surface of the sample container 7.

In this case, since the upper surface of the sample container 7 is cut to have the same spherical surface as the curved surface of the flying object 5 measured in advance, the entire surface of the sample container 7 collides at the same time. As a result, collisions occur in vertical and oblique directions on all surfaces except for one point in the center, and a vertical and oblique shock wave is applied to the sample container 7 and the sample 8.

The results in this case are also approximately the same numerical values as in Experimental Example 1, so a description thereof will be omitted.

(Effects of the Invention) As described above, the present invention utilizes the shock wave caused by the collision of a high-speed flying object or the detonation shock wave caused by the explosion of an explosive to impact-compress a solid material. Since shock compression is performed while forming oblique shock waves of more than 100%, it enables active and high-speed mass transfer in solid materials at relatively low temperatures.

Therefore, it is easy to promote chemical reactions and phase changes, and since the chemical reactions and phase changes occur at low temperatures, there is almost no return phenomenon such as reactions after passing through shock waves or detonation shock waves, and the recovery rate of products is high. will improve.

Therefore, it is possible to efficiently synthesize high-pressure phase materials such as diamond and to synthesize dense sintered bodies from powders that involve chemical reactions.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of a conventional planar impact compression device using the direct method, Fig. 2 is a longitudinal cross-sectional view of a planar impact compression device also using the indirect method, Fig. 3 is a temperature-pressure correlation diagram of carbon, and Fig. 4 is the relationship diagram between the flying plate impact velocity and the conversion rate to diamond, No. 5
Figure 6 is a schematic diagram of an oblique shock wave, Figure 6 is an explanatory diagram of the range of an oblique collision, Figure 7 is a vertical cross-sectional view of the impact compression device using the indirect method using the oblique shock wave of the present invention, and Figure 8 is a sample container. In the diagrams shown, (a) is a top view when concentric unevenness is provided, (opening) is a top view when parallel unevenness is provided, and (c) is a top view on the diameter of (a) or (opening). Figure 9 is a cross-sectional view of the sample container and the flying object, where (A) is a composite surface of triangular protrusions, (A) is a curved protrusion, (C) (2) is the case of a composite surface of a triangular protrusion and a curved protrusion; (2) is the case of a cylindrical sample container with a triangular protrusion; FIG. (a) is a perspective view, (opening) is a longitudinal sectional view, (c) is a plan view of the detonator part, FIG. Figure 12 shows a cylindrical device using an indirect method using oblique shock waves according to the present invention. FIG. 8 is a longitudinal sectional view of a modification of the device shown in FIG. 7, with the explosive lens omitted; 2: Explosive lens, 3: Main explosive, 7: Sample container, 8: Sample. : Flying object, Nuimoshi K゛hegamatsukyokiC%) 5th note #jj''; 4 pieces of vise ((;a) Ki 7th note B note 9th (A) C mouth) (YU) Notebook 11

Claims (1)

[Scope of Claims] 1) A sample container loaded with a solid material and a flying object when impact-compressing a solid material using a shock wave caused by a collision of a high-speed flying object or a detonation shock wave caused by an explosion of an explosive. one or more planes on which part or all of the surface on which the shock wave or the detonation shock wave starts acting is vertically oblique to a plane perpendicular to the collision direction of the projectile or the explosion direction of the explosive; or a curved surface or a composite surface thereof, and is characterized by impact compression while forming one or more types of oblique shock waves in the sample container and the solid material by the action of the shock wave or the detonation shock wave. Impact compression method. 2) In a solid material impact compression device that causes a high-speed flying object to collide with a sample container loaded with a solid material, a parallel space is placed above the surface where the impact wave starts to be incident upon impact of the flying object. Further, an explosive and a detonating means are provided on the upper side of the projectile, and the explosion of the explosive by the detonating means accelerates the lower projectile downward or diagonally downward, and the sample container loaded with the solid material is In an apparatus for shock-compressing the solid material by impact, part or all of the surface on which the shock wave of the sample container and the flying object starts acting is in a positional relationship perpendicular and oblique to the direction of impact of the flying object. An impact compression device for a solid material, characterized in that it is composed of two or more flat or curved surfaces or a combination of these surfaces. 3) An explosive layer is arranged above the surface on which the detonation shock wave caused by the explosion of the explosive is made to be incident on the sample container loaded with the solid material of the impact compression device which detonates the explosive and directly impact compresses the solid material, and this explosive layer is In an apparatus in which an explosive layer is detonated by the detonating means, and a solid material is impact-compressed by the accompanying detonation shock wave, one of the surfaces of the sample container loaded with the solid material on which the detonation shock wave begins to act. 1. An impact compression device for a solid material, characterized in that part or all of the device is composed of one or more flat surfaces, curved surfaces, or a combination of these surfaces, which are perpendicular to and oblique to the detonation direction of the explosive.