Synthesis of Ti-N thin films prepared by dynamic ion mixing technique and their mechanical properties

Abstract

Ti-N thin films were formed on unheated Si(100) substrate with evaporation of Ti by electron beam and simultaneous bombardment of N ion beam in the range of 1–40 keV. The influence of N ion acceleration energies and the content ratios (N/Ti) on microstructures and phases was investigated by X-ray diffraction (XRD), Auger electron spectroscopy (AES) and transmission electron microscopy (TEM). The XRD spectra revealed the formation regions of the single phases and the mixture phases for α-Ti, the stoichometric compounds TiN and Ti2N, at the various ion acceleration energies. The mechanical properties such as hardness, elastic modulus, adhesive strength and friction coefficient were also investigated. Nano-indentation studies showed that the hardness and the elastic moduli for each phase increased with increasing mixing layer thickness in relation to the ion acceleration energy. The single phase TiN and Ti2N films prepared at higher ion energy showed excellent mechanical properties in the hardness and adhesive strength. The relationships between other mechanical properties of the obtained films and their phases were also discussed.