Investigation of corrosion and tribological characteristics of annealed CrN/CrAlN coatings deposited by CAE-PVD

In this work, the variation of tribological and corrosion performances of as-deposited and annealed CrN/CrAlN multilayer coatings on 304 stainless steel substrates deposited by the cathodic arc evaporation process was investigated. It was found that annealing resulted in the decomposition of CrN to Cr2N. Also, the surface roughness increased as the annealing temperature increased due to the coalescence of macroparticles. Thus, the wettability of annealed samples decreased as the annealing temperature increased. The hardness decreased as the annealing temperature increased due to the increase in the crystallite size. The sample annealed at 400 degrees C had the lowest wear rate of 3.04 x 10-5 mm3/Nm and 6.4 x 10-5 mm3/Nm in ambient air and Ringer's solution, respectively, due to the optimum ratio of CrN and Cr2N, minimum crystallite growth, and optimum adhesion strength. Based on the electrochemical impedance spectroscopy results, the highest corrosion resistance was observed in the specimen annealed at 700 degrees C, which can be attributed to the existence of Cr2N and larger crystallite size in this multilayer coating.

Automated summary

This study investigated the tribological and corrosion performances of as-deposited and annealed CrN/CrAlN multilayer coatings on 304 stainless steel substrates deposited by cathodic arc evaporation process. The results showed that annealing led to the decomposition of CrN into Cr2N. Additionally, the surface roughness and wettability of the annealed samples increased as the annealing temperature increased. The hardness decreased due to the increase in crystallite size. The sample annealed at 400 degrees C exhibited the lowest wear rate and the specimen annealed at 700 degrees C showed the highest corrosion resistance.