Effect of N2 partial pressure on the structural and mechanical properties of TaN films

TaN films with different N2 partial pressure were deposited on 304 stainless steel using the magnetron sputtering method. The effect of gas pressure on the mechanical property, morphology and phase structure of the films is investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), microhardness testing, friction coefficient measurements, and wear mechanism study. The XRD results confirmed that increasing N2 partial pressure does not affect the formation of the new phases but intensity of peaks increased. AFM images showed that surface roughness and grain size increased with increasing of N2 partial pressure. It was found that hardness decreased as N2 partial pressure increased. From the friction coefficient measurements, it could be inferred that the friction coefficient increased as N2 partial pressure increased. The images of samples after wear test showed that with increasing N2 partial pressure wear resistance decreased. The results show that the partial pressure of N2 has a great influence on the mechanical properties.