Synthesizing High-Quality Diamond Based on Indirect Heating Method and Dynamic Matching Technology of Pressure and Temperature

Abstract:

Inside the indirect heating chamber, raw material itself is not being electrified nor giving out heat. Instead, heat is offered by some heater outside and transferred inside to heat the raw material indirectly. Gradient of pressure parallels to as well as matches with that of temperature, which solves the mismatch between these two elements inside the high-pressure chamber. Meanwhile, both electrical resistance and temperature remain unchanged when raw material reacts. What described above realizes uniformity and stability of pressure and temperature. During the process of synthesizing diamond, we employ the technology of two-parameter dynamic matching of pressure and temperature. In this way, attached load increases gradually while attached power decreases little by little to keep pressure and temperature in the rich diamond crystal growth area and allow them to move in a restricted area in direction of identical quality line. As a result, pressure and temperature can match dynamically and diamond crystal can grow steadily and continuously in a long time period to produce high-quality product, per unit output reaches as much as 580cts, 60% of which are of high grade.

• Periodical: Key Engineering Materials (Volumes 589-590)
• Pages: 611-616
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.589-590.611
• Online since: October 2013
• Authors: Qin Sheng Wang, Jin Bin Lu, Qing Guo Zhao, Yu Lin, Pei Pei Ru
• Keywords: Dynamic Matching, Indirect Heating, Synthesizing Technology, Synthetic Diamond

References

[1] Qinsheng Wang editor in chief, Superhard materials making, (China Standard Publishing House, Beijing, 2004).

[2] Qinsheng Wang editor in chief, Superhard materials & products, (Zhengzhou University Press, Zhengzhou, 2006).

[3] Chinese patent, Heat diamond synthetic piece indirectly, ZL200, 620, 029, 870. 2.

[4] Chinese patent, Diamond synthesizing chamber heater, 200, 620, 031, 974. 7.

[5] De Beers Standard Diamond Grit Product Range, (1996).

[6] Prama diaSDB1000, De Beers Industrial diamond, (2000).

[7] Qinsheng Wang editor in chief, Diamond & Abrasive Engineering, Vol. 3(2000), p.1.

[8] Rondeau B, Fritsch E, Moore M, et al. On the growth of natural octahedral diamond upon a fibrous core [J]. Journal of Crystal Growth, Vol. 304(2007), p.287.

DOI: 10.1016/j.jcrysgro.2007.03.004

[9] James C. Sung, Michael Sung. Emily Sung Diamond growth on array of seeds: The revolution of diamond production [J]. Thin Solid Films, Vol. 498(2006), p.212.

DOI: 10.1016/j.tsf.2005.07.091

[10] Jinbin Lu editor in chief, Diamond & Abrasive Engineering, Vol, 6(2010), p.50.

[11] Blank V D , Kuznetsov M S , Nosukhin S A , et al. The influence of crstallization temperature and boron cencentration in growth environment on its distribution in growth ectors of type II b diamond [J]. Diamond Relat. Mater. Vol, 16(2007), p.800.

DOI: 10.1016/j.diamond.2006.12.010

[12] Abbaschian R , Zhu H , Clarke C . High pressure-high temperature growth of diamond crystals using split sphere apparatus [J]. Diamond Relat. Mater. Vol, 14(2005), p. (1916).

DOI: 10.1016/j.diamond.2005.09.007