Improved cavitation erosion resistance of TiSiN/TiN multilayer coating with Al addition

Abstract

This work studied the effect of Al addition on the mechanical property and cavitation erosion resistance of TiSiN/TiN and TiSiN/TiAlN multilayer coatings. Adding Al into TiSiN/TiN elevates hardness from 17.8 GPa to 20.1 GPa and H³/E² ratio from 0.050 GPa to 0.082 GPa, while refining average grain size from 7.3 nm to 5.9 nm through substitutional solid solution formation. The modified TiSiN/TiAlN system demonstrates exceptional cavitation performance, extending incubation duration beyond 20 h with maximum mass loss rate reduced from 215 μg/h to 4 μg/h, compared to 12-hour incubation period of TiSiN/TiN coating. This notable enhancement is attributed to Al-induced grain refinement in the TiSiN/TiAlN coating, which increases toughness and enables efficient energy dissipation from cavitation pulses, thereby improving fatigue limit and delaying crack initiation.