Structure, mechanical and tribological properties in seawater of multilayer TiSiN/Ni coatings prepared by cathodic arc method

Abstract

The monolayer TiSiN and multilayer TiSiN/Ni coatings were deposited on the surface of Ti6Al4V alloy and Si wafer through cathodic arc method. By analysis, the TiSiN layer presented an amorphous/nanocrystalline structure. The adhesion force and toughness of multilayer TiSiN/Ni coatings could be significantly improved by the insertion of Ni layer. Meanwhile, the modulation ratio of Ni and TiSiN layers greatly affected the tribology behavior of multilayer TiSiN/Ni coatings in seawater. With the increase of modulation ratio, the anti-wear ability of multilayer TiSiN/Ni coating increased firstly and then decreased. When the modulation ratio was 1:5, the multilayer TiSiN/Ni coatings displayed the lowest friction coefficient (COF) of 0.14 and wear rate of 1.06 × 10−6 mm3/Nm in seawater, which was about 53.33% and 62.81% lower than that of monolayer TiSiN coating, respectively. This was mainly due to the complexity of penetration path caused by the multilayer structure and the inhibition of crack extension caused by the improvement of toughness.