Abstract:The TiC→DLC gradient composite films were characterized systematically. The elemental depth profile and elemental chemical state evolution were determined by X-ray photoelectron spectroscopy (XPS). The transmission electron microscope (TEM) and high-resolution transmission electron microscopy (HRTEM) were used to study the structure of interfacial zone between DLC film and Ti-C layers. Results show that there are composition transition zone between DLC film and either Ti-C layer or steel substrate on condition that pre-deposited Ti layers on the steel substrate then plasma based bias deposited DLC films. In Ti-C graded layer, the chemical state of titanium and carbon are changed gradually. The structures of zone in Ti-C layer near the DLC film is consisted of random oriented nanocrystallines TiC dispersed in amorphous DLC matrix. The structure of the zone between DLC film and Ti-C graded layer is gradually changed too.

Key words: gradient composite films; DLC films; composition; structure