How To Improve the Quality of Synthetic Diamond Single Crystal
Author:liliang Time:2018-08-10 16:49:30
As one of the major members among the superhard material, synthetic diamond single crystals have developed rapidly recently. This is an important achievement of ultra-high pressure and high temperature technology. The quality of the high-pressure mold, the volume of the reaction chamber volume, and the control level of pressure and temperature during the synthesis process have been used as a measure of the production and research level of a country's superhard materials. At the same time, the consumption of superhard materials in a country has become one of the important indicators.
The production of synthetic diamond in China has experienced the production of abrasive grades to high-strength high-quality single crystals and polycrystals since the 1960s, and it has developed rapidly, which could basically meet domestic demand and some exports. Of course, further improving the quality of single crystals, reducing the consumption of raw materials, and developing functional materials are still the focus of our future work.
The quality of synthetic diamond single crystal is determined by the strength, the shape of the crystal, the quality of the bubble, the depth of the color and other factors. The intensity value is the most important indicator.
At present, the synthetic equipment used in various countries in the world are different, and the six-face hydraulic press is the main model for producing synthetic diamond single crystal and polycrystalline in China. At the beginning of industrial scale production, the domestic six-face hydraulic press is a single model of 3600 tons. The diameter of the synthetic cavity is only 10.5mm, and the single crystal size is small. It belongs to the abrasive grade. When the 4800-ton hydraulic press appeared, the working cylinder diameter was 320mm, and the horizontal bar supercharger was equipped with a PC model, which was already dominant. To this end, China's synthetic diamond single crystal production level has reached a new level. The quality of the single crystal is significantly improved. Therefore, advanced equipment is very important to improve the quality of diamond.
People are aware that in the diamond industry, the optimization of the process system is limited, and the updating of equipment is also conditional, so the focus is gradually transferred to the innovative raw materials. The carbon sheet is a carbon source for the growth of a synthetic diamond single crystal and a heating element for generating a high temperature, and has strict requirements on technical parameters such as purity, graphitization degree, porosity, grain size and geometric size. The growth of diamond single crystal is closely related to the quality of the carbon source. Therefore, the improvement of the carbon sheet should be highly valued before production. Innovative catalytic materials are the key to breaking the strength of diamond single crystals. The catalyst can greatly reduce the pressure and temperature of graphite conversion to diamond during the synthesis process. As a fixed pressure transmission medium, pyrophyllite is widely used in the production of synthetic diamond. It has good electrical insulation and thermal insulation and thermal stability. It can meet the synthesis requirements.