Diamond deposition on thin cylindrical substrates

Diamond coatings were deposited onto different cylindrical sub- strates (Cu, SiC, W and Mo) by the hot filament chemical vapor deposition (CVD) method. Continuous, adhered and well-faceted crystalline coatings of diamond were obtained on Cu-wire using a special pretreatment with a mixture of diamond and metal powders as well as carefully controlled deposition at lower power. Diamond deposition on SiC-fiber gave continuous and uniform coatings when only the filament power was properly selected. Uniform, homo- geneous, euchedral diamond coatings on W- and Mo-wires, attained at a higher filament power, confirmed once more the convenience of refractory metals as substrates for diamond deposition by the CVD technique. Characterization of the obtained coatings was realized using scanning electron microscopy (SEM). The obtained results are compared with the literature data. Differences are dis- cussed with regard to the chemical nature of the substrates as well as their ther- mophysical characteristics.