D.G. Piliptsou

Synthesis of Diamond-Like Carbon Film on Copper and Titanium Interlayer by Vacuum Cathode Arc Evaporation

Using direct-current (DC) and pulsed double-excitation cathode arc plasma technique, diamond-like carbon (DLC) bilayers with nano-scaled interlayer of Cu and Ti were synthesized on silicon substrate. The effect of interlayer on the structure, morphology and mechanical properties of bilayer films were investigated. The change in bilayers structure occurred during interlayer introduction and greatly affected the hardness and internal stress of bilayers. Interlayer nature changed the microstructure of bilayers that in the thickness and element content of diffusion layer. Ti/DLC bilayer exhibited a similarly morphological character to DLC monolayer, whereas Cu interlayer in DLC films leaded to a formation of nanostructured surface and lower root mean square roughness due to the absence of Cu-C bond.

Influences of Pulse Frequency on Structure and Mechanical Properties of DLC Films Synthesized by Pulsed Cathodic Arc Evaporation

Diamond-like carbon (DLC) films were prepared on the Si (100) substrates by pulsed cathodic arc plasma. The influences of given pulse frequency on the microstructure, morphology, mechanical and optical properties of DLC films were investigated by Raman spectroscopy, atomic force microscopy, Knoop sclerometer, X-ray double-crystal surface profilometer. The results showed that the variation of pulse frequency could significantly change the microstructure of DLC films, including the size and ordering of sp2 carbon clusters and movement or diffusion of carbon atoms. The increasing of pulse frequency led to the variation of the relative fraction of Csp3/Csp2. The hardness and internal stress of the DLC films were affected accordingly. The results might contribute to the synthesis of DLC films with excellent structure and properties by cathodic arc evaporation.

Structure and Mechanical Properties of (Cu, Ti) - Binary Metal Doped Diamond-Like Carbon Films

The composite DLC films doped with different content of Cu, Ti unitary and binary metal have been deposited on stainless steel and silicon substrate using DC-magnetic separation and pulse cathode double-excitation source plasma arc deposition technique. Structural and mechanical properties of the films were investigated by Raman spectroscopy, Atomic Force Microscope, micro-sclerometer and surface profilometer. The results indicated that the hardness and internal stress of Cu-DLC films decrease upon incremental content of copper from 0 to15 at.%. More attractively, a simultaneous improvement of the hardness (31GPa) as well as the release of the internal stress (up to 55%) can be achievable for samples with the relative atomic percentages of Ti and Cu contents of 43.6% and 1.56% respectively.