Tribological Behaviors of CrN/CrAlSiN Coatings in Seawater

To improve the tribological performance of sea frictional components, CrN/CrAlSiN coating was deposited on 316L stainless steel by multi-arc ion plating technique. The composition and microstructures of the coatings were characterized by XRD, XPS, SEM and TEM. The hardness of the coatings was measured using nanoindentation. The friction and wear properties of the coatings were investigated using a ball-on-disk tribometer in the atmosphere and seawater. The results show that the synthesized CrN/CrAlSiN coating exhibits nanostructured composite microstructures consisting of CrN, A1N and amorphous Si_3N_4 encapsulated nano-crystallite with a stronger (111) preferred orientation. Based on the design of intermediate layer of the CrN/CrAlSiN coating, the hardness of the coating amount to 35.5 GPa. With respect to the 316L substrate, the coating has a good corrosion resistance due to its dense structure. In the atmosphere and seawater environments, the friction coefficient and wear rate of the CrN/CrAlSiN coating significantly reduce compared to 316L, which is in the optimum state in the seawater