Properties of amorphous SiC coatings deposited on WC-Co substrates

in this work, silicon carbide films were deposited onto tungsten carbide from a sintered sic target on a r.f. magnetron sputtering system. based on previous results about the influence of r.f. power and argon pressure upon the properties of films deposited on silicon substrates, suitable conditions were chosen to produce high quality films on wc-co pieces. deposition parameters were chosen in order to obtain high deposition rates (about 30 nm/min at 400 w rf power) and acceptable residual stresses (1.5 gpa). argon pressure affects the energy of particles so that films with higher hardness (30 gpa) were obtained at low pressures (0.05 pa). wear rates of the coated pieces against a chromium steel ball in a diamond suspension medium were found to be about half of the uncoated ones. hardness and wear resistance measurements were done also in thermally annealed (200-800 °c) samples revealing the effectiveness of sic coatings to protect tool material against severe mechanical degradation resulting of high temperature (above 500 °c) oxidation.