Papers by Keyword: DC-PCVD

Abstract: The method of carbon nanotubes by DC-PCVD is analysed. Growth environment of carbon nanotubes is researched with the substrate temperature at 500°C-900°C.The pressure of gas is 60torr,75torr,90torr.It is appropriate when the temperature is 700°C and the pressure is 75torr.Growth characteristic of carbon nanotubes is researched when the concentration of CH4 ranges is 8%-20%.The diameter of carbon nanotubes is uniform when the concentration of CH4 is low.The diameter is not uniform if the concentration is high.

Abstract: The DC plasma chemical vapor deposition (DC-PCVD) method was a promising technique to fabricate CVD diamond coatings in industry, because it has many good properties, such as high grown rate of diamond films, big grown area, high qualities, and cost effective. In the present work, we synthesized diamond films on cemented carbide (YG6) substrates, and studied the different nitric acid aqueous solution treatment durations influence on diamond nucleation stage. The results indicated that well-chosen nitric acid aqueous solution treatment durations should be selected. For too short treatment times, the residual Co will promote the carbon transform from diamond metastable phase into graphite stable phase. On the other side, too long treatment times will consume too much Co, which will lead to the shortage of cohesive body, and finally the crackers in the bulk propagated and peeled off with the diamond films well grown on WC grains.