WC-Co substrate preparation and deposition conditions for high adhesion of CVD diamond coating Preparação do substrato de WC-Co e condições de deposição para alta adesão de revestimento de diamante CVD

Different substrate surface pretreatments have been used to improve the adhesion of CVD diamond coatings on WC-Co substrates. This paper reports the results of a pretreatment method based on two-step chemical etching: first in Murakami solution and then in aqua regia. A systematic study was performed to evaluate the influence of the pretreatment on the composition and morphology of the WC-Co substrate. Furthermore, the effect of diamond nanoparticle seeding on the morphology and roughness of the substrate was also investigated. After these studies, diamond coating was deposited on seeded WC-Co substrate by hot-filament CVD. The sample was characterized by Raman spectroscopy, FEG-SEM and AFM. Rockwell C indentation test was used to evaluate the adhesion between the CVD diamond coating and the WC-Co substrate.