Examining the Evolution of Microstructure and ITS Effect on the Mechanical and Tribological Properties

Abstract

This paper investigates the superior frictional performance of Ti-DLC films, by examining the evolution of microstructure and its effect on the mechanical and tribological properties. The superior frictional performance of Ti-DLC films can be attributed to the special microstructure related to the development of embedded fullerene-like microstructures as a result of incorporation of TiO2 clusters. The factors contributing to the ultralow friction include high hardness and cohesion, excellent toughness, and high load bearing capacity (brought by the increased crosslinking and elastic energy storage ability), the friction-induced structural transformation rendering an ultralow shear resistance and the excellent resistance to oxidation-induced mechanical property degradation (due to the doped TiO2). The Raman, high resolution transmission electron microscopy, atomic force microscope and micro-indentation measurements consistently reveal or indicate the formation of curved graphene sheets or fullerene-like microstructures with increasing CH4/Ar ratio.