E. I. Meletis, V. Singh, S. Pal, Louisiana State University, Baton Rouge, LA
DLC films, known for exhibiting attractive tribological properties, have been extensively studied in the past. Inherent drawbacks in these films are their low thermal stability above 400°C, adhesion and fracture toughness. Carbide formers incorporated into the carbon network, have the potential to stabilize the film structure and improve performance. The present work focuses on the synthesis, structure and tribological properties of nanocomposite Cr-DLC and N-doped Cr-DLC films. A plasma-assisted hybrid CVD/PVD process was utilized to synthesize the films in a discharge composed of a CH4 and Ar(N2) gas mixture. Film microstructure and composition have been studied by high-resolution TEM, EDS and NRA. The chemical state of Cr and N in the films was investigated by XPS. The effect of Cr and N on the tribological behavior of DLC films was studied by conducting pin-on-disc experiments. The tribological behavior of these films is discussed in view of their microstructural characteristics.
Summary: The present work focuses on the synthesis, structure and tribological properties of Cr-DLC films and N-doped Cr-DLC films. Incorporation of Cr and N into the carbon network has the potential to stabilize the film structure and alleviate several drawbacks of DLC films such as low thermal stability.