The anti-sand erosion performance of TiN films fabricated by filtered cathodic vacuum arc technique at different nitrogen flow rates

In order to improve and verify the anti-sand erosion performance of TiN film, a series of TiN films were fabricated using filtered cathodic vacuum arc technique by controlling nitrogen flow rate. The phase constituents and mechanical properties with variation of nitrogen flow rate were investigated. The nitrogen deficient phases of TiN _0.30 , Ti ₂ N and TiN _0.61 decreased with increasing nitrogen flow rate, and the hardness of film increased monotonically from 16.77 GPa to 28.56 GPa. The results suggested that sand erosion was a complex process, where multiple mechanical properties contributed to the anti-sand erosion performance of TiN films. When the hardness of film was lower than a critical value of 23 GPa, the films exhibited poor anti-sand erosion performance. While for the films with high enough hardness, excessive residual stress was one of the main factors decreasing the anti-sand erosion performance of TiN films. It was demonstrated that by adjusting the phase constituents in TiN films, the variation of nitrogen flow rates made the mechanical properties of films quite different, and it ultimately showed a critical influence on the anti-sand erosion performance of TiN films. Especially, a better TiN film featuring the preferred orientation of TiN (111), the appropriate hardness of 27.33 GPa, the lowest residual stress of −2.15 GPa and the best anti-sand erosion performance was achieved at nitrogen flow rate of 20 sccm.