Application of Raman Spectroscopy for Analyzing Diamond Coatings on a Hard Alloy

Single- and multilayer coatings of micro- and nanocrystalline diamond were deposited on tungsten carbide substrates (WC + 6 wt.% Co alloy) in a microwave plasma of methane/hydrogen and methane/hydrogen/nitrogen mixtures. Barrier tungsten layers were used to improve adhesion of the diamond coatings to the substrates. Raman spectroscopy was used to study the properties of the nano- and microcrystalline diamond coatings depending on the deposition parameters. Data on structural transformations of the coatings under different tribological contact conditions were obtained, and secondary nucleation processes were investigated on different diamond faces during the deposition from the gas phase.