Coatings, Vol. 6, Pages 39: Deposition and Characterization of Si-Doped Diamond Films Using Tetraethoxysilane onto a WC-Co Substrate

Silicon-doped (Si-doped) diamond films were deposited on a Co-cemented tungsten carbide (WC-Co) substrate using the hot filament chemical vapor deposition (HFCVD) method with a mixture of acetone, tetraethoxysilane (TEOS), and hydrogen as the recant source. The as-deposited doped diamond films were characterized with field emission scanning electron microscopy (FE-SEM), Raman spectrum, and X-ray diffraction (XRD). Furthermore, Rockwell C indentation tests were conducted to evaluate the adhesion of the Si-doped diamond films grown on the WC-Co substrate. The results demonstrated that the silicon concentration in the reactant source played an important role in the surface morphology and adhesion of diamond films. The size of diamond grain varied from 3 μm to 500 nm with silicon concentration increasing from 0 to 1.41 atom %. When the silicon concentration rose to 1.81 atom %, the grain size became bigger than that of the lower concentration. The ratio of diamond peak {220}/{111} varied with different silicon concentrations. Raman study features revealed high purity of as-deposited diamond films. The Raman spectra also demonstrated the presence of silicon in the diamond films with Si–Si, Si–C and Si–O bonds. Si-doped diamond films with strong adhesive strength on the WC-Co substrate was beneficial for diamond films applied on cutting tools and wear resistance components.

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