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BARS apparatus

Schematic of a BARS system. Pressure chamber. Two BARS devices, one open for loading or unloading and the other closed. BARS (or "split sphere", transliteration from Russian : Б...

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Schematic of a BARS system.
Pressure chamber.
Two BARS devices, one open for loading or unloading and the other closed.

BARS (or "split sphere", transliteration from Russian: БАРСabbreviation of Russian: Беспрессовая Аппаратура Высокого Давления «РАЗРЕЗНАЯ СФЕРА», (bespressovaya apparatura vysokogo davleniya «razreznaya sfera»), "press-free high-pressure setup «split sphere»") a high-pressure high-temperature apparatus usually used for growing or processing minerals, especially diamond and boron nitride.[1] Typical pressures and temperatures achievable with BARS are 10 GPa (99,000 atm) and 2,500 °C (4,530 °F; 2,770 K).[2][1]

The BARS technology was invented around 1989–1991 by the scientists from the Institute of Geology and Geophysics of the Siberian Branch of the Academy of Sciences of the USSR.[2] In the center of the device, there is a ceramic cylindrical reaction cell of about 2 cm3 in size. The cell is placed into a cubic-shaped pressure-transmitting material, which is pressed by elements made from cemented carbide (VK10 hard alloy).[3] The outer octahedral cavity is pressed by 8 steel sectors. After mounting, the whole assembly is locked in a disc-type barrel with a diameter ~1 meter. The barrel is filled with oil, which pressurizes upon heating; the oil pressure is transferred to the central cell. The central cell is heated up by a coaxial graphite heater. Temperature is measured with a thermocouple. The exterior size is 2.2 х 1.0 х 1.2 meters. The weight of the sphere is 2.8 tonnes (6,200 lb), and the claimed energy consumption is in between 1.5 - 2 kWh.[4]

The growth rate for 5 carats (1.0 g)type Ib (yellow, nitrogen-rich) crystals using Fe–Ni catalyst reaches as high as ~20 mg/h towards the end of 100 h growth cycle, i.e. crystals of 5 carats (1.0 g) to 6 carats (1.2 g) can be grown in less than 100 h.[5]

See also

Referencias

  1. ^ " Беспрессовая аппаратура высокого давления "РАЗРЕЗНАЯ СФЕРА" (БАРС)" . www.igm.nsc.ru (en ruso) . Consultado el 16 de mayo de 2018 .
  2. 1 2 N. Pal'yanov; et al. (2002). "Fundidos de carbonato alcalino portadores de fluidos como medio para la formación de diamantes en el manto terrestre: un estudio experimental". Lithos . 60 ( 3– 4): 145. Bibcode : 2002Litho..60..145P . doi : 10.1016/S0024-4937(01)00079-2 . 
  3. ↑ MG Loshak y LI Alexandrova (2001). "Aumento de la eficiencia del uso de carburos cementados como matriz de pernos que contienen diamante para herramientas de destrucción de rocas". Int. J. Refractory Metals and Hard Materials . 19 : 5. doi : 10.1016/S0263-4368(00)00039-1 .
  4. ↑ "Беспрессовая аппаратура высокого давления "РАЗРЕЗНАЯ СФЕРА" (БАРС)" . www.igm.nsc.ru (en ruso) . Consultado el 16 de mayo de 2018 . оптимальные габариты (2,2 х 1,0 х 1,2 м) и масса установки (2,8 т); высокая экологичность и безопасность; низкая энергоемкость (1,5 - 2 квт/час); заменяемость многопуансонного блока в зависимости от задач
  5. ↑ R. Abbaschian; et al. (2005). "Crecimiento de cristales de diamante a alta presión y alta temperatura utilizando un aparato de esfera dividida". Diam. Relat. Mater . 14 ( 11–12 ): 1916. Bibcode : 2005DRM....14.1916A . doi : 10.1016/j.diamond.2005.09.007 . 
  • hpht – alta presión, alta temperatura
  • Equipo de alta presión sin prensado “SPLIT SPHERE” Archivado el 20/07/2011 en Wayback Machine
  • Amenaza sintética para los diamantes de calidad gema