The Diamonds Big Bang In China

Although China was a latecomer for diamond synthesis, and their technology has been crude, however, they have evolved as the major production country of industrial diamond grits. In 2007, China produced 800 tons (4 billion carats) of diamond grits that account for more than 80% of the world production. The reason that Chinese could become the powerhouse of diamond grits production was actually triggered by their inability to make large dies for making ultrahigh pressure apparatus (the belt system). The large dies are made of cemented tungsten carbide that often breaks if the sintering is not homogeneous. In order to circumvent this problem, Chinese were forced to use cubic presses that use anvils to substitute the enclosure of the die (Fig. 4.17). Although such technology was judged rudimentary, Chinese were able to scale up cubic presses for mass production of diamond grits. It was fortuitous that die-free cubic press could cost less for manufacturing because large dies are expensive consumable parts. As a result of low cost production, leading diamond companies were forced to reorganize. For example, De Beers Industrial Diamonds was restructured as Element Six. GE Superabrasives were sold twice as Diamond Innovations (now under Sandvik).

The Chinese taking over of the diamond grits production is now upgrading with a new technology that allow the random nucleation of diamond by patterned diamond seeding (Fig. 4.18). This technology was invented by the author (US Patent Nos. 6,159,286; 7,172,745; and 7,323,049).

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