Tribocorrosion behaviors of TiSiCN nanocomposite coatings deposited by high power impulse magnetron sputtering

High-performance coatings originated in ingenious coating designs and advanced preparation techniques are expected to fulfill imperious demands in propulsion, bearings and mechanical seals, etc in marine systems for seawater lubrication. In this work, TiSiCN nanocomposite coatings were deposited by high power impulse magnetron sputtering at a power of 4–8 kW. As power is increased, TiSiCN coatings possess nanocrystalline (TiN, TiC, TiCN)/amorphous (Si 3 N 4 , SiC, sp 2 -C) nanocomposite structure without distinctly preferred orientation. The highest hardness (H) of 43 GPa and effective Young’s modulus (E*) of 360 GPa were achieved at 8 kW, while the highest H/E* of 0.123 and H 3 /E* 2 of 0.61 appear at 7 kW due to refined nano-grains, uniform distribution, high surface/interface integrity and fully dense microstructure. Rockwell C adhesion level increased from HF2 at 4 kW to HF1 at 8 kW. TiSiCN coatings with high H, H/E*, H 3 /E* 2 and adhesion exhibit high open circuit potential of −0.07 V, low friction coefficient of 0.25 and specific wear rate of 4.78 × 10 −5 mm 3 N −1 m −1 , resulting from mild abrasive wear without the occurrence of pitting corrosion in 3.5 wt.% NaCl aqueous solution. Moreover, cycling tribocorrosion tests revealed that passive films possess strong abilities of regeneration and self-repairation on sliding contact surface.