New set up for diamond coatings deposition in AC glow discharge plasma on WC-Co milling cutters of complex shape

摘要

In the current work, we developed a new type of CVD reactor for high-speed deposition of uniform diamond coatings on WC-Co milling cutters in AC glow discharge plasma with two plasma channels in the Ar/H-2/CH4 atmosphere. This CVD system successfully allowed one to deposit well-adherent MCD, UNCD and Multilayer diamond coatings with a thickness up to 60 gm on WC-Co milling cutters of various geometries and with a diameter up to 14 mm. We found that to minimize the edge effect, the optimal energy input for each plasma cord should be set in the range of 1.4-2.5 kW. We also found that diluting the H-2/CH4 atmosphere with argon in the range of 45-80% vol. is one of the necessary conditions to control the deposition process. Diamond deposition rate has been achieved up to 2.5-3 mu m/h with a uniformity of deposition over 50% from maximum thickness. Presented CVD system is very promising due to sufficiently high deposition rate and ease of implementation, and it also has great potential for industrial scaling.