ZhongNan Diamond Co.

Nanyang, China

ZhongNan Diamond Co.

Nanyang, China

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Jia P.,Zhongnan Diamond Co.. | Liu Q.,Zhongnan Diamond Co.. | He W.,Zhongnan Diamond Co.. | Qi Y.,Zhongnan Diamond Co.. | Zhou L.,Zhongnan Diamond Co..
Jingangshi yu Moliao Moju Gongcheng/Diamond and Abrasives Engineering | Year: 2015

In order to prolong anvil life and improve the quality of synthesized diamond, the cooling mode of anvil was studied and optimized. Cooling water could keep the anvil at a lower temperature and reduce the anvil abrasion. But it could lead to a non-uniform temperature field inside the anvil and increase 8% of polycrystalline. In our present work, cooling six anvils simultaneously and independently was an effective way to balance temperature distribution inside the furnace and improve the quality of synthetic diamond. Results showed that it not only reduced anvil abrasion by 61%, but also improved diamond quality with 15% less polycrystalline and 8% increased concentration. ©, 2015, Zhengzhou Institute of Abrasives Grinding. All right reserved.


Yang H.,Beijing Institute of Technology | Mai L.-B.,China North Standardization Research Center | Lu C.-H.,ZhongNan Diamond Co. | Tong Y.,Beijing Institute of Technology | And 3 more authors.
Journal of Beijing Institute of Technology (English Edition) | Year: 2016

The method, in which a few carats of diamond grits are placed inside a capsule together with a steel ball, shaken for a number of times, and the unbroken ratio of the grits is then used to evaluate the quality of the diamond, has been well established for many years. However, the unbroken percentage, in an equivalent view, represents the impact toughness of the grits and cannot reflect the value of the crushing energy. Most of the previous empirical formulas obtained from experiments by scholars cannot be applied to practical tests. In this paper, a dimensional analysis was applied to investigate the impact toughness experiment, and the dimensionless relationship has been built among those variables such as the toughness index, the impact time, the impact frequency and the crushing energy per unit area. According to the results of a large number of experiments with synthetic diamond grits of mesh size 45/50, the percentage of the broken grits H is proportional to the impact time T1.14 when the impact frequency is 2 400 r/min, and the impact frequency f2.576 when the number of impacts is 2 000. © 2016 Beijing Institute of Technology.


Lu C.,Zhongnan Diamond Co. | Wang Z.,Zhongnan Diamond Co. | Zhang F.,Zhongnan Diamond Co. | Zhao J.,Zhongnan Diamond Co.
Jingangshi yu Moliao Moju Gongcheng/Diamond and Abrasives Engineering | Year: 2015

A series of experiments were made to discuss the main reason causing diamond grits fracture during impact process. Effects of steel ball mass, surface treatment and using time on impact toughness index of diamond were analyze through impact toughness tests. Results showed that even a small difference of steel ball mass would produce quite an effect on the stability of test result; and that at the same mass, sanded steel ball could effectively enhance the stability and accuracy of the impact toughness test results. It was also concluded that when the steel ball was used for no more than 3 times, the results were relatively stable. ©, 2015, Zhengzhou Institute of Abrasives Grinding. All right reserved.


Lu C.,Zhongnan Diamond Co. | Zhang T.,Zhongnan Diamond Co. | Liu J.,Zhongnan Diamond Co. | Dou M.,Zhongnan Diamond Co.
Jingangshi yu Moliao Moju Gongcheng/Diamond and Abrasives Engineering | Year: 2015

φ55 mm PCD compacts were synthesized on cubic press using 2-peak high quality diamond powder with nano catalyst. The compacts were made into cutting tools to test the performance. Results showed that abrasive ratio was more than 230000. The compact performed good thermal stability at 2 min and 700 ℃. Micro ultrasonic image indicated that there were no defects such as delamination, crack, inclusion. When used to cut the tungsten carbide, the performance of samples could be comparable to similar with foreign products. © 2015, Zhengzhou Institute of Abrasives Grinding. All right reserved.


Tian L.,Henan Polytechnic Institute | Bao Y.,Zhongnan Diamond Co. | Zhang Y.,Zhongnan Diamond Co.
Jingangshi yu Moliao Moju Gongcheng/Diamond and Abrasives Engineering | Year: 2015

This paper introduces constant line grinding speed equipment based on the PLC electric control system, the framework and measurement structure of equipment as well as program software control system. It selects PC1H-200Y PLC of OMRON and laser displacement sensor to implement equipment control and verifies the reliability of the equipment and achieves constant line speed grinding requirement. © 2015, Zhengzhou Institute of Abrasives Grinding. All right reserved.


Liu S.-Y.,Zhongnan Diamond Co. | Zhang Y.-B.,Zhongnan Diamond Co. | Yuan N.-N.,Zhongnan Diamond Co. | Ning J.,Nanyang Environmental Protection Bureau | Li Q.,Nanyang Environmental Protection Bureau
Jingangshi yu Moliao Moju Gongcheng/Diamond and Abrasives Engineering | Year: 2014

Combined with the wastewater problems in diamond production and the process requirements of circulating water, the process of wastewater recycling treatment is discussed. Results show that by adding alkali, heavy metal becomes precipitation which can be filtrated physically, while waste water becomes recycling water, with its pH higher, containing trace amount of Ni and high concentration of NaCl. Waste acid in reactor are collected and recycled. The electrolytic bags are drained when taken out of the electrolytic cell. The electrolytic material are collected as well. Thus both directions of accumulation and osmosis are controlled, although some fresh water are slightly added. In this way the production pollutes none but earns both environmentally and economically.


Jia P.,Zhongnan Diamond Co. | Liu Q.-K.,Zhongnan Diamond Co. | He W.-J.,Zhongnan Diamond Co. | Qi Y.-J.,Zhongnan Diamond Co. | Zhang D.-S.,Zhongnan Diamond Co.
Jingangshi yu Moliao Moju Gongcheng/Diamond and Abrasives Engineering | Year: 2014

Comparative experiment was conducted to study the effects of carbon-paper's structure on diamond synthesis, and a new composite carbon-paper was developed. The results showed that the new composite carbon-paper not only made the conductive-plug ablation rate 30% lower than using normal carbon-paper, i.e. making the synthetic process more stable, but also reduced the polycrystalline proportion 10% lower than that of normal carbon-paper, greatly improving the quality of synthetic diamond.


Yang H.,Beijing Institute of Technology | Mai L.-B.,China North Standardization Research Center | Lu C.-H.,ZhongNan Diamond Co. | Tong Y.,Beijing Institute of Technology | And 3 more authors.
Applied Mechanics and Materials | Year: 2014

Toughness index is an important parameter of the quality of super-abrasive grits. In order to improve the design of the toughness index tester more reasonably and efficiently, we calculated the velocity of a steel ball in the capsule and simulated the impact process between the steel ball and the different capsule end faces with the ANSYS/LS-DYNA. The main results are as follows: (I) the maximum velocity of the ball is approximately 2.0106m/s. (II) with the increase of the curvature, the maximum value of normal stress declines while the effective area rises. (III) the maximum shear stress cannot cause diamond grits to break directly, but it can make small cracks and defects of the impacted grits propagate. These assertions are validated by the simulation which explains the experimental phenomenon well. © (2014) Trans Tech Publications, Switzerland.


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Zhongnan Diamond Co. | Date: 2012-01-24

Synthetic diamonds.

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