Evaluation of the internal friction and elastic modulus of the superhard films

In this paper, the vibrating-reed technique was used to measure the elastic modulus and internal fiction of the superhard thin films on the stainless steel substrate. The general formulas for evaluation of the internal fiction and the Young’s modulus of the film were derived for the sample with a rectangular section. The Young’s modulus of the nanocomposite superhard TiN/Si3N4 films on stainless steel is about 420–460 GPa at room temperature and decreases with increasing temperature. The internal fiction of the two-side deposited films is small and increases with temperature, while the internal friction of one-side deposited film is large and decreases with temperature due to the larger internal stress in the film.