Diamond manufacturing method
Shrrry Huang
www.boreway.net
2016-01-28 15:23:24
Direct method
Synthetic diamond or high-temperature ultra-high pressure technique utilizing instantaneous static or dynamic ultra-high pressure high temperature technology, or a mixture of both techniques, graphite and other carbonaceous materials directly from the solid or molten state transition into diamond, diamond obtained in this way are micron size polycrystalline powder.
Melting media law
Synthetic diamond static EHV (50 ~ 100kb, namely 5 ~ 10GPa) and high temperature (1100 ~ 3000 ° C) technology reacted by graphite, diamond carbonaceous feedstock and certain metals (alloys), the typical crystalline cube ( hexahedron), octahedron and six - octahedral and their transitional forms. Showing important applications in industry mainly static pressure melt the media law. Using this method to give abrasive grade synthetic diamond production has more than natural diamond, the problem to be solved is to increase the ratio of coarse, increase conversion rates and improve the crystal quality. Laboratory studies are being borne by large particles method Static melting quality single crystal diamond formation. Seeding epitaxial growth of large single crystals had a weight of about 1 kt; after slightly improved with the general testing techniques, had received about 2 to 4 mmCrystals. With this method also a big particle growth and sintering of polycrystalline diamond, which the industry has been in a certain application, the key issue is to further improve this polycrystalline diamond compressive strength, impact strength, abrasion resistance and overall performance and heat resistance.
Epitaxy
Synthetic diamond is the use of pyrolysis and electrolysis certain carbonaceous material deposited carbon on the diamond seed or certain substances from the base effect from the epitaxial growth.
Wurtz reaction methodLet CTC and sodium at 700 ℃ reaction of diamond. But it will also generate a large amount of graphite.
Formation mechanism
Mainly has the following several theories: the theory that the solvent metal (alloy) plays the role of carbon in the solvent; catalysis theory is considered to be a catalyst; solid phase transition theory emphasizes the disintegration of the graphite crystal without bond breaking, after a simple form deformation Diamond crystals. But the doctrine of the proposed three typical models tend to contradict experiment with some of the major phenomena and laws. Accordingly, there has been solvent - catalyst,catalyst- Solvent, melt (melting) agent - catalyst (referred to as the melting medium) to further investigate the role of other theories of metals (alloys) used. In general, synthetic diamond formation mechanism are still being explored yet is a complex issue.
