Influence of V content on properties of Ti–W–V–N films

Abstract

Ti–W–V–N composite films with different vanadium contents were synthesised by multi-target reactive magnetron sputtering. The microstructure, mechanical and tribological properties of Ti–W–V–N films were investigated by X-ray diffraction, scanning electron microscope, high-resolution transmission electron microscopy, nanoindentation and high-temperature ball-on-disc tribometer. The results showed that all the Ti–W–V–N composite films were face-centred cubic (fcc) structure, consisting of fcc-(Ti,W,V)N substitutional solid solution. When the V content ≥21.5 at.-%, the films consisted of fcc-(Ti,W,V)N and fcc-VN. The hardness of the films first increased and then decreased with the maximum value of 32.4 GPa, at 21.5 at.-% V. The test temperature had a significant effect on the tribological properties of Ti–W–V–N film with 21.5 at.-% V, the coefficient of friction (CoF) first increased and then decreased, with a minimum value of 0.304 at 700°C.While the wear rate increased gradually with increasing temperature.