Tribological properties of (Ti, Al)N films with different Al/Ti atomic ratios deposited by magnetron sputtering

Abstract

Magnetron sputtering was used to deposit (Ti, Al)N films with different Al/Ti atomic ratios by changing the current of the Al target and to study their tribological properties. The phase composition, microstructure and elemental distribution of films were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS). The influence of the ratio between Al and Ti atoms on the tribological properties and the mechanical properties of the films was analyzed. The conclusions showed that there was a tendency for films to shift from the crystalline to the amorphous state as the Al/Ti atomic ratio increases. Herein, changes in film microhardness were related to the substitution relationship between Ti atoms and Al atoms. Especially, when the Al/Ti atomic ratio was 0.54, coefficient of friction (COF) and specific wear rate were the lowest. Compared with TiN film, (Ti, Al)N films have higher microhardness due to the solid solution hardening caused by the substitution between Al and Ti atoms to produce lattice distortion. These factors make films have excellent tribology performance.