Characterization of cascade arc assisted CVD diamond-coating technology: Part II. Coating properties and applications

The cascade arc assisted chemical vapor deposition (CACVD) reactor is capable of producing high-quality diamond coatings to accommodate high-volume production. This reactor has demonstrated the ability to deposit polycrystalline diamond coatings with high uniformity and industrial-scale productivity. Precise control of plasma parameters as well as thermal management of substrates allows for optimization of coating deposition on substrates of different materials having various geometries. Approximately 1000 cylindrical substrates 2 mm diameter×20 mm long can be mounted and coated simultaneously in the industrial tubular CACVD reactor with 1-m-long reaction zone. The coating properties were studied by electron microscopy and Raman spectroscopy. The influence of various predeposition treatments on coating properties was investigated. A comparison of characteristics of films deposited on carbide, Mo, W and stainless steel substrates is also presented. The correlation between the morphology of CVD diamond coatings vs. substrate material and its position in the reactor chamber was assessed using micro-Raman spectroscopy and secondary electron microscopy. There was no indication to suggest the relationship between the substrate position in the reactor and coating properties.