The Structure And Properties Of CrAlSiN Coatings Using The Cathodic Arc Ion Plating Deposition Technique

CrAlSiN coating has become one of the research hotspots in the field of coating due to its good mechanical properties and friction and corrosion resistance.In this paper,CrAlSiN coating was deposited on 316L stainless steel substrate by arc ion plating technique.Scanning electron microscopy（SEM）,multifunctional X-ray photoelectron spectroscopy（XPS）,transmission electron microscopy（TEM）,polycrystalline X-ray diffraction（XRD）,electrochemical workstation,nano-indentation,the reciprocating ball-on-disc module Rtec-tribometer,scratch tester and other equipment were used for characterizing the properties of the surface,thickness,structure,chemical composition and other factors of the coating with different silicon content,different bias and different transition layer.Meanwhile,the friction and corrosion resistance were studied.The conclusions are as follows:（1）When the content of silicon is 3.7%,the coating exhibited excellent comprehensive properties under the seawater condition.The hardness,friction coefficient and friction rate were 36.5 GPa,0.160,3×10^-7 mm³/N·m,respectively.（2）With the change of the bias voltage from-20V to-60V,the large particles on the coating surface reduced,and the size was refined;the increasing of the negative bias enhanced the bombardment effect,which increased the density and hardness.At-60V,the values of H/E and H³/E² were 0.100 and 0437 GPa respectively,which were the highest.While at-40V,the friction coefficient and the wear rate were minimum;the corrosion current density was the lowest 9.47×10^-5 A/cm²;Rpore and Rct were the maximum values,and the coating showed excellent performance in the friction and corrosion resistance.（3）The synthesized CrAlSiN coating exhibit nanostructured composite microstr-uctures consisting of CrN、AlN and amorphous Si₃N₄ encapsulated nano-crystallite with a stronger（111）preferred orientation.The design of intermediate layer of the CrAlSiN coating makes the hardness of the coating amount to 32.1 GPa、35.5 GPa、37.9 GPa.With respect to the 316L substrate,the coating has a good corrosion resistance due to dense structure.In the atmosphere and seawater environments,the COF and wear loss of the Cr/CrN/CrAlSiN coating significantly reduce with regard to CrAlSiN and Cr/CrAlSiN,which is the optimum state in the seawater.