Processing and Characterization of Functionally Graded Ti/TixCy/DLC Thin Film Coatings

Functionally gradient diamond-like carbon-based thin films of 2.19-3.90 micron thickness were prepared on high speed steel substrates, using hybrid equipment which combined magnetron sputtering with plasma enhanced chemical vapour deposition in the same vacuum chamber. Initially, a layer of Ti was deposited by magnetron sputtering, then acetylene gas was gradually introduced into the chamber to obtain graded TixCy coatings. Finally a diamond-like carbon coating was deposited by blocking the magnetron cathode with a shield. Elemental depth profiling by secondary ion mass spectrometry and electron probe microanalysis confirmed the functionally gradient structure. The TiC grains had a columnar structure. The load required to remove the coating, determined by scratch testing, was 35.5-68 N. 6 refs.