Effect of Nitrogen Addition on Synthesis of Nanocrystalline Diamond Films on Tungsten Carbide Substrate by Flame Combustion Method Using High-Purity Acetylene

Abstract

A flame combustion method enables the synthesis of diamond using acetylene-oxygen in ambient atmosphere. It has various advantages over other methods, such as in terms of speed, safety and cost. Tungsten carbide (WC) is used as cutting tools in the machining industry. In this study, to obtain nanocrystalline diamond films and to achieve good adhesion on the WC substrate, diamond films were synthesized by flame combustion using a mixture of high-purity acetylene and oxygen gas with the addition of nitrogen gas. Nitrogen gas added as the nanocrystalline diamond promotion agent; nitrogen flow rate was varied. The results indicated that, at the mixture of high-purity acetylene and oxygen gas, the diamond nanocrystallites was not synthesized on the diamond microcrystallites at nitrogen flow rate 0.000 cm3/s. As nitrogen flow rate was increased, the diamond nanocrystallites was synthesized on the microcrystallites. The diamond nanocrystallites was synthesized with high density all over the diamond microcrystallites.