2013年7月26日星期五

Synthetic diamond single crystal


synthetic diamond single crystal
Graphite materials with a catalytic agent in the high temperature alloy (13000C), high pressure (5000 MPa) pressure under the above conditions, the crystal growth of

diamond called again synthetic diamond crystal. Synthesis of single-crystal multi-static catalyst method (also blasting method). Pressure through the hydraulic

machine, such as

Cubic Press 6 from the direction perpendicular to both located in the center of the cube sample pressure; temperature is AC or DC generated by heating the sample

through the graphite. High-strength synthetic diamond single crystal, in order for the manufacture of impregnated polycrystalline diamond drill bits, drilling in

Hard formation; higher strength before making hard and hard formations using diamond impregnated drill bit. Synthetic diamond single crystals are small size, its large

particles (> 100 mesh) is used as the impregnated bit; micronized, then as an abrasive paste, in the machinery manufacturing and is widely used in building materials

industry

. Under heat and pressure of the carbon atoms into diamond.

Magnetism of synthetic diamond single crystal mechanical properties


For synthetic diamond single crystal magnetic separation experiments carried out research on the basis of the various samples were static strength, impact strength and

thermal shock strength and other aspects of analysis and testing. The results show that the magnetism of the mechanical properties of single crystal synthetic diamond

has a significant impact. Gold

Magnetic diamond single crystal, the stronger the deeper the color of its exterior, interior air bubbles and impurities and defects, the more surface finish worse, its

static strength, impact strength at room temperature (IT) and thermal shock strength index (ITT) value lower. Magnetic at room temperature for static strength and

impact strength of the impact

Impact is relatively small, while the maximum thermal impact strength.
Diamond is the world's hardest substance known, has excellent mechanical, thermal, optical, electrical, acoustic and chemical overall performance, is an important

quality structural materials, is also great potential for the development of functional materials. polycrystalline diamond can be used for aluminum, copper and other nonferrous metals

efficient

Quality processing, particularly suitable for processing hard and brittle non-metallic materials, only a small part directly for grinding, polishing, and other

processes outside of the coating.

Development Trend of synthetic diamond


Because synthetic diamond in various industrial areas to be more widely used, synthetic diamond market's overall demand will continue to grow steadily, the market

price will be flat to down, for processing non-metallic materials and construction of industrial diamond proportion will continue to account for

Dominant position, the blade coarse grade high-strength products will continue to sell.
According to the different needs of industrial applications developed product series and special products, to further improve the standard varieties, inexpensive and

low-grade synthetic diamond abrasive tools products in developing countries will have greater development.
Emerging high-tech products, industrial single crystal of large particles and nano-scale ultra-fine powder products began to enter the market, the use of a large

single crystal synthetic diamond particles made of a single piece diamond tool has been successfully applied in industry, indicates that a comprehensive industrial

synthetic diamond replace the natural

Diamond has come of age.
Low pressure chemical vapor deposition (CVD) technology has made significant progress in the diamond film as a new structural materials and functional materials are

entering the market, clearly showing that new applications of synthetic diamond broad prospects for development.
Static method and the diamond press production of synthetic diamond is still today the most important methods and equipment, various types of synthetic devices have

their own strengths, press large-scale industrial development of synthetic diamond is an inevitable trend.
Dynamic method has embarked on industrial synthetic diamond production scale, new synthetic methods (such as liquid phase epitaxy method, laser method, etc.) will

cause widespread concern. With the continuous development of world science and technology, synthetic diamond industry in the world by a few countries (public

Division) monopoly era has passed, production layout direction towards multipolarity, Asia will become the new century industrial development of synthetic diamond "hot

spot" areas. In the 21st century, building materials, geology, oil and gas, electronics, automotive and other industries will require a lot of

Diamond, synthetic polycrystalline diamond market demand will be more vigorous, more brilliant prospects

How to produce a synthetic diamond


American physicist P? W? Bridgman massive support to create high pressure high temperature devices for the synthesis of synthetic diamond material foundation. Shortly

thereafter, another member of superhard materials CBN come out. China in 1963 by several trillion Newton Institute in cooperation 2

Synthesized on both sides of the diamond anvil press, 1965 in the laboratory to obtain small particles of cubic boron nitride, currently the vast majority of

industrial synthetic diamond produced using this technology, people often referred to as a static high pressure high temperature technology . Furthermore it later

Another invention of synthetic diamond technology - explosive synthesis techniques, the use of high temperature and pressure generated by the explosion of synthetic

diamond. Synthesized in this way very fine diamond particles, is used as a diamond polishing powder and grinding paste.
After the advent of synthetic diamond, the rapid expansion of its field of application is mainly made of various tools. Their application from the initial geological

exploration soon extended to stone processing, energy development, water conservancy, electric power, construction, roads, airports and other engineering and precision

machining, wood processing,

Rubber, glass, special ceramics, optics and the automotive industry and other direction. The use of diamond tools for the development of various fields have had a

profound impact, the most important is the production efficiency, allowing for the increasing demand for industrial diamond. Nearly 20 years, the world

Diamond and product development are in the 12 percent average annual growth rate, far higher than the growth rate of industrial development, it is predicted that for

quite a long time to remain above 8% growth rate. Relevant data show that per capita consumption of a country's industrial diamond certain extent

Degree reflects the level of industrial development of the country. Cubic boron nitride (CBN) is also very optimistic about the prospects for the application of its

superior physical, chemical and mechanical properties, especially for iron-group metal materials processing, which are complementary and diamond for processing hard

and brittle non-metallic materials.
According to statistics, the world's annual production of synthetic diamond over one billion kt (1 kt = 200 mg), far higher than the tens of millions of carats of

natural diamonds mined. Ours is a big country of diamond production, production accounts for over 50% of world production. However, China has been the hinge

Chain cubic press as the main production equipment (the number of the total production equipment more than 95%). Due to equipment capacity and conditions, the current

output is mainly low and middle diamond, product oversupply, exports less competitive. Study of the non-artificial crystals

Graduate School developed with independent intellectual property rights on both sides of the top 25 trillion Newtonian synthesis equipment and technology, based on

domestic resources, with its own characteristics, after nearly 10 years of industrial production, mature technology, the production of diamond quality and stability,

and performance is quite similar foreign products .
The application of the current diamond watch, people just use their high hardness properties. Diamond also has many other excellent properties, such as the fastest

speed of sound, the most appropriate wavelengths, the highest thermal conductivity, high Young's modulus, etc. These characteristics are being developed materials

Application. Next period of time in addition to the regular production of general tools diamond, the diamond will be primarily one large and one small two aspects of

development. Large diamond crystal is further to the large size of the development, the largest known industrial-grade single crystal has reached 38? 4 kt, large scale

Inch single crystal synthetic diamond on the development of many excellent properties is very important. Little is more fine-grained synthetic diamond, such as nano-

diamond, many research institutions in carrying out research and development of nano-diamond, has come on the market, but at present

Still in the experimental stage, higher production costs. Such as Japan, the use of nano-diamond carbon control into a color display. Furthermore nanodiamonds in

energy, life sciences and other fields are also promising. It is obvious that the polycrystalline diamond is not only an important structural materials are

Is a great application prospects functional materials, it is the 21st century, many of the most active areas of materials research one of the materials.

The relationship between artificial diamond and graphite


Chemical composition of graphite and synthetic diamond are carbon. Different is that one is a flat network structure, a three-dimensional structure of space. Graphite Diamond

has a "twin brother" called graphene. Compared to hard wear-resistant diamond, graphite is very very soft texture. Since diamond hard

Degree and nature of the graphite both have such a big difference, why put Talia called "twin brother" mean? Chemist to tell you: the chemical composition of diamond

and graphite are identical, except that they are not the same crystal structure. We have just seen the diamond

Structure, the structure of graphite on the map is. polycrystalline diamond is very different than the right? Flaky graphite crystals, which was dark gray, opaque and metallic luster.

Good conductivity, temperature, thermal conductivity is also very good. Graphite soft. It can be used to make brushes electrode

, Dry battery carbon rod, used in manufacturing metal smelting and brick graphite crucible, graphite powder can be used for high temperature operation of the machine

lubricant, can be made pencil. Seen in the crystal world of the "twin brothers" have their own skills, they all have their

Useless.
Graphite and diamond hardness vary so much, but people still want to be able to get the diamond synthetic method, because the nature of graphite (carbon) reserves are

very rich. However, to make into a diamond carbon in graphite are arranged as carbon, is not so easy

The. Graphite 5-6 million atmospheres ((5-6) × 103MPa) and 1000 to 2000 ° C temperatures, then the metallic iron, cobalt, nickel and the like as catalyst, can

graphite into diamond.

How to identify synthetic diamonds and natural diamonds


Diamond (Diamond), mineral name is diamond, is recognized as the king of gems. Its greatest feature is the highest hardness and highly refractive, in light shine,

dazzling. But its surface with glass, crystal and artificial synthetic diamond similar to more difficult to identify.

Accurate identification only by instrumentation, and easy identification of the following methods may be used:
1. Hardness testing diamonds are the hardest known naturally occurring substance, nothing can draw on the diamond marks, if marked by traces is by no means polycrystalline diamond .
(2) Thermal resistance test to be identified in diamonds and other similar articles breath while, if the surface of the diamond should be higher than the other

condensed mist mist on the items faster evaporation, because diamond has high thermal conductivity causes .
3 Observe the reflected light can be observed with a magnifying glass diamond Waist presents a very fine matte-like and have a bright reflected light crystal products.

This feature of the diamond is unique.
4. Observed under a magnifying glass to see the growing point, genuine diamond crystal surface often ditch continued and growing point of the triangle, then see these

characteristics in terms of fakes. "
Imitation diamond imitations three categories:
① added alumina ordinary glass, because the refractive index and dispersion improved, easy mistake, but the hardness is low. ② synthetic zirconia imitation, high

hardness, refraction good, but will be reflected in the rotation more IPL, with the real thing in the rotation only reflected a weak yellow, blue and white

Phototherapy, compared with significant differences.
⑧ with colorless synthetic sapphire and spinel imitation, hardness close, but there is a low refractive index and birefringence, ghosting visible under a magnifying

glass.

High hardness diamond


Synthetic atom density per unit volume than any existing pumping solids synthetic diamond, its hardness than natural diamond, called the world's most hard materials.

With natural diamond containing ninety-nine percent of the carbon-13 isotope. According to the scientists observed, with the carbon-13

Isotope intensity increases, the distance between atoms will be slightly reduced, prompting the hardness of diamond atomic arrangement slightly loose than natural

diamond. In the course of synthetic diamond , the first process by chemical vapor enriched isotope carbon-13 A

Alkyl gas carbon precipitation into polycrystalline diamond small pieces, and then use very high pressure to break down these small pieces, and then crystallized into weight up to 3

carat diamond block.