RU1398155C - Method of making high pressure chamber with diamond anvil - Google Patents

Description

(46) 06/15/93. Bull. K-22

(21) 4068595/26,

(22) 05.19.86

(71) Institute for High Pressure Physics named after L.F. Vereshchagina

(72) A.Ya. Preobrazhensky, N.S. Kalichki- on, V.S. Voblikov and V.A. Borovikova

(56) U.S. Patent No. 4,260,397, cl. 51-37, 1979

(54) METHOD FOR CREATING A HIGH PRESSURE CHAMBER WITH A DIAMOND ANVIL

(57) The invention relates to high pressure technology and can be used to achieve and study high compression ratios. The method makes it possible to obtain a high-pressure chamber with a diamond anvil and tungsten-diamond support in a carbide shell, which has an increased fastening strength of a single crystal in support and increased hardness of support. This is achieved by pre-pressing a diamond single crystal into a blank of isotropic non-diamond carbon, then the blank with a diamond single crystal is surrounded by a layer of hard alloy and crystallization of non-diamond carbon into a polycrystalline diamond is performed by splicing it with an oily single-crystal anvil under pressure 80- 85 kbar for a pulsed heating of 0.5-1 s at 1800-2000 C. In addition, this method allows to obtain a povjagenny camera volume by choosing the design of diamond support at storage of the level of pressure achieved. The chamber created by this method allows physical, chemical and biological studies to be carried out over a wide range of temperatures, in which they are necessary. optical methods of exposure or the use of electromagnetic fields, 1 nl.

With

oo

ate

Sd

The invention relates to a high pressure technique and can be used to achieve and study high degrees of compression of a substance.

The aim of the invention is to increase the strength of the fastening of a single crystal of diamond and support and vypyuyu hardness of the sub, arms,

The drawing shows a high-pressure chamber manufactured by the proposed method.

The camera contains a shazpuy monocrystalline and perfect 1 and support 2 of polycrystalline diamond carbide 3

The use of pressing a diamond anvil single crystal into a preform. Support of isotropic non-diamond carbon provides reliable mechanical contact and a single dimensional cut of a single crystal anvil diamond under the influence of external pressure, the isostaticity of which is also achieved through the use of a powdery, carbide alloy holes surrounding a piece of wealmazed carbon with a diamond anvil pressed into it, The outer diameter of the carbide shell refers to the diameter of a monocryst lla as a 3: 1 .. A symmetrical about tnositelno diamond anvil perifer1-1ynoe location carbide carbide shell, performing a role as a heater.

and diamond forming catalyst, provides a symmetrical nature of the heating and fusion of the resulting

of non-diamond carbon polycrystalline diamond with a diamond single crystal novovpnk., I warn you

accumulation of metal-catalyst, mechanical and thermal overvoltages on the contact surface with the anvil. The possibility of carrying out a crystallization process at higher than in

 The known method of pressure and temperature values, also facilitated by the use of an improved arrangement, composition and structure of the starting materials, leads to a reduction in the duration of the process by more than 1000 times, the formation of a uniform strong micro-diamond, its coalescence with a diamond anvil, and an increase in the size of the support - living: diamond anvil contact

5

0

5

0

5

0

5

0

5

voltages. The support of the diamond anvil from the side of the polycrystalline diamond is growing compared to the support in the known method as the pressure and temperature of formation of the polycrystalline diamond increase, due to the refinement of its structure and the greater cohesion of the diamond grains with each other and to the diamond on the anvil, as well as due to all the strength and hardness of the carbide shell surrounding the polycrystalline diamond and hardened at maximum process parameters and a larger value voltage at the interface between carbide and diamond polycrystal, which is achieved as a result of an increase in the mechanical properties of a carbide under the influence of hardening under elevated PT conditions. The crystallization conditions of non-diamond carbon allow I

to maintain in polycrystalline diamond the geometrical shape of the initial part from isotropic carbon and thus be made, in contrast to the known method, relying on the increased mechanical characteristics of the resulting polycrystalline diamond in a carbide shell, high pressure chamber. The presence of the working volume of the high-pressure chamber is achieved by increasing the height by 1.03-1, 1 polycrystalline diamond support 2 above the working plane of the diamond anvil, 1 and opens up the possibility of significantly expanding the field of research and synthesis of substances in large volumes. An increase in the height of more than 1.1 times above the working plane of the diamond anvil, as shown by experiments, leads to cleavage of the polycrystalline diamond support during further use of the chamber under high pressure. The creation of reliable support for a single-crystal diamond anvil allows us to switch to the use of millimeter-sized single crystals instead of the unsupported diamonds 5 fm used in known designs. Such a replacement, in addition to a large economic gain, gives advantages, and in the strength of the device itself} due to the operation of an honest

large-scale fluctorp — with a decrease in crystal size, all other things being equal, observers. 1 with a tendency to lower its defectiveness and, consequently, to increase mechanical strength. The presence of a high-pressure carbide layer sintered under high pressure, especially firmly covering the diamond support of the anvil from the outside, gives. design advantages and simplifies the necessary processing in the process of linking the device to a high-pressure installation,

For the creation of a high-pressure chamber, graphite of the MPG6 brand was used. Graphites of this group have a finer-grained and more homogeneous structure compared to graphites of other grades; for the creation of the chamber, isometric single crystals of diamond were used (the thickness of the diamond single crystal is close. , It is permissible to use single crystals with a thickness of 1.5 times less than the diameter of the central part of the single crystal.

The preliminary pressing of single crystals of diamond into a graphite billet involves parallel anvils, and during crystallization only shrinkage occurs (polycrystalline diamond, support (during the transformation of graphite into polycrystalline diamond).

With respect to the diamond anvil, the peripheral arrangement of the carbide carbide shell provides a symmetrical pattern of heating and intergrowth of the polycrystalline diamond with the diamond anvil single crystal. Example 1. A container of lithographic stone is placed in a high-pressure and temperature chamber. Inside

..the container is placed a single crystal of diamond weighing 0.3 carats and a diameter of 3.0 mm, pre-pressed into a cylindrical billet with a diameter of 4.5 mm (5 mm) from isotropic graphite grade MPGB, and surrounded by a shell 2 mm thick of solid. alloy grade T15K6. Then, the container so equipped is exposed to a pressure of 80 kbar and a pulsed iarpe.ny lasting about 1 s at 1800 s, as a result of which the graphite part is transformed into a polycrystalline diamond and durable cf;

,

5 5

0

to

about

5 g

5

it on the inner surface with a tper-, alloy plate. Half of the high pressure chamber is obtained. The same operations are repeated to obtain the second half of the high pressure chamber. The high-pressure chamber thus obtained with polycrystalline diamond support and a centrally located single-crystal diamond anvil is bonded externally to a carbide shell. In the test, the substrate was characterized by high rigidity (5-7), hardness in the range of 100000-1AOOOO mn / m and polycrystalline diamond type carbonado (10 mn / m). EXAMPLE 2. Everything is as in example 1, only equipped the container is subjected to a pressure of 75 kbar and pulsed heating with a duration of 1 s at 1800 ° C. As a result, the graphite part transforms into a polycrystalline diamond, its solid fusion with the carbide shell, but cracks are observed on the surface of the polycrystalline diamond due to the lack of pressure in the reaction zone.

PRI me R 3. Everything is as in example 1, only a single crystal of diamond weighing 0.7 carats and a diameter of 3.5 mm, pre-pressed into a cylindrical billet with a diameter of 12.25 mm (mm) from isotropic graphite grade MPGB, surround 4 mm thick shell made of T15K6 grade hard alloy. The empty container is subjected to a pressure of 85 kbar and pulsed heating for a duration of 0.5 s at 2000 s. As a result, the graphite part is transformed into a polycrystalline diamond and its solid fusion on the inner surface with a carbide shell. Similarly, the second half of the high pressure chamber is obtained. The high-pressure chamber thus obtained with polycrystalline diamond support and a centrally located single-crystal diamond anvil, fastened on the outside with a hard alloy shell, was characterized by high rigidity (5-7) 10 GN, hardness within 140,000 m / m and polycrystalline support strength carbonado type diamond

5

Tl Example A. A container of lithographic stone is placed in a high-pressure and temperature chamber. A diamond single crystal weighing O, 1 carat and 2.5 mm in diameter is placed inside the container, pre-pressed into a cylindrical billet with a diameter of 3f5 mm (, 5 mm) made of MPG6 isotropic graphite so that the single crystal is recessed and the graphite blank by 0.5 mm below the upper end face of the workpiece d A top from the kitlenite plug is placed, the profile of which repeats the profile of the upper end face of the single crystal in the graphite workpiece. The single crystal, pressed into a graphite billet, is surrounded by a shell of a T15K6 grade alloy of 2-3 mm thickness. Then, the container equipped in this way is subjected to a pressure of 80 kbar and pulsed heating for about 1 s at a time, as a result of which the graphite part is transformed into a polycrystalline diamond and its fusion is stronger along the internal groove, like with a carbide shell. Thus, half the high-pressure chamber is obtained. The same operations are repeated to obtain the second half of the pressure chamber. The high-pressure chamber thus obtained has a larger volume due to the fact that the height of the polycrystalline diamond support is O, 1 mm higher than the working surface of the diamond anvil, which makes it possible to examine or synthesize samples with large lengths, since the obtained working volume of the chamber is obtained on the order of 0.2 mm. The hardness of support is 100000-140000 mn / m, the strength is 103 mn / m.

PRI me R 5. Everything as in example 4,

only diamond single crystal weighing 0.5

1

5 o „

5

5

556

carat and with a diameter of 4 mm but pressed into the workpiece with a diameter of 6.5 mm, 0 mm). The single crystal is recessed in a graphite preform 0.8 mm below the upper end of the preform. All operations are repeated as in Example 4. The high-pressure chamber thus obtained has a larger volume (5 mm) due to the fact that the height of the polycristiopic diamond support is 0.5 mm higher than the working surface of the diamond anvil. The hardness of support is 100000-140000 mn / m, the strength is 10 mn / m.

Claims (2)

1. A method of creating a high-pressure chamber with a diamond anvil, including the effect of high pressure and temperature on a diamond single crystal placed in the Support blank, characterized in that, in order to increase the fastening strength of the diamond single crystal in support and increase the hardness of the support, the diamond single crystal is pre-pressed into a blank of isotropic non-diamond carbon at Relative to the diameter of the workpiece and the diameter of the diamond single crystal 1.5-3.5, the workpiece is surrounded by a layer of hard alloy, the outer diameter of which relates to the diameter of the single crystal as (3-6): 1, and is subjected to a pressure of 80-85 kbar during it -, pulse heating 0.5-1 s at 1800 - 2000 C. 2. The method according to claim 1, characterized in that, in order to increase the working volume of the high-pressure chamber., A support height is performed. Bbmie of the working surface of the diamond anvil, comprising 1.03-1.1 the height of the diamond anvil. Compiled by L. Gor Yunova  Editor T. Kurkova Tehred M. Dydyk Corrector N. Demchik Order 2374 Circulation VNIIIPI of the State Committee of the USSR for matters of inventions and postcards - 113035, Moscow, Zh-35 Rauska nab., d. 4/5. For writing but / in