| Nickel/hydrogenated amorphous carbon composite films have been deposited on silicon and stainless steel substrates by combining sputter-deposition of metal and microwave plasma-assisted chemical vapor deposition of carbon from argon-acetylene mixtures containing 10% to 100% of C2H2. The composition of films was investigated as a function of the C2H2 concentration in the gas phase by Rutherford backscattering spectroscopy (RBS), nuclear reaction analysis (NRA) and elastic recoil detection analysis (ERDA). The crystallographic structure of films was investigated by X-ray diffraction (XRD) techniques. The grain size of nickel and nickel carbide Ni3C was found to be in the nanometer range. The nanohardness and Young modulus of films were deduced from the load-displacement nanoindentation curves. The maximum nanohardness of 14 GPa was obtained for films produced in gas mixtures containing 25-35% of C2H2. The magnitude of residual stresses was obtained from the measurement of the radius of curvature of silicon substrates and film-substrate samples. The maximum magnitude of compressive residual stresses was 0.8 GPa for films deposited in gas mixture containing 25-35% of C2H2. The tribological tests were conducted at room temperature in the ball-on-disc geometry using alumina balls. The minimum value of friction coefficient was 0.23 for films deposited from gas mixtures containing 70-80 vol.% of acetylene. |
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