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The corrosion behavior of the TiN monolayer and CrN/TiN multilayer coatings deposited via cathodic arc evaporation physical vapor deposition (CAE‐PVD) on the Ti–6Al–4V substrates were evaluated in Ringer's and Hank's physiological saline electrolytes. XRD (x‐ray diffractometry) and scanning electron microscopy (SEM) analysis were used to characterize the coatings. The corrosion behavior of coatings was assessed by impedance spectroscopy and potentiodynamic polarization techniques. The results showed that the corrosion resistance of coatings was increased in the order of TiN‐Ringer's < TiN‐Hank's < CrN/TiN‐Ringer's < CrN/TiN‐Hank's. Therefore, it can be concluded that the CrN/TiN coating, due to having a large number of interfaces and a smoother surface with fewer macroparticles and pinholes, is more efficient in raising the corrosion resistance properties of titanium than TiN monolayer coating. Moreover, it was observed that Ringer's solution is a more severe environment than Hank's solution. Both coatings, because of the precipitation of a protective corrosion products layer on their surface, showed an enhancement in corrosion resistance with increasing the immersion time from 1 to 14 days in Hank's. The results suggest TiN monolayer and CrN/TiN multilayer coatings as promising candidates for biomedical applications. [ABSTRACT FROM AUTHOR]

This paper aims to study the tribological and electrochemical properties of the CrN/AlCrN nano-layer deposited on H13 tool steel. Arc physical technique was employed to deposit multilayer coating. X-ray diffraction technique, thermionic and field emission scanning electron microscopy and energy dispersive spectroscopy have been used to determine the characteristics of the samples. To study the samples' wear behavior, coating adhesion, and surface hardness, reciprocating wear test, Rockwell-C test, and microhardness Vickers tester were employed, respectively. The measured values of the coefficient of friction and the calculated wear rates showed that the CrN/AlCrN multilayer coating has a much higher wear resistance than the uncoated sample. The coefficient of the friction of the coated sample was 0.53 and that of the uncoated sample was 0.78. Moreover, the wear rate of the coated H13 steel was about 127 times lower than the bare H13 steel sample. The results obtained from electrochemical impedance spectroscopy and polarization tests demonstrated that the corrosion current density of the H13 steel sample was 8 μA/cm² and that of the CrN/AlCrN multilayer-coated sample was 3 μA/cm². In addition, the polarization resistance of the treated and the substrate specimens was estimated at 4.2 and 2.7 kΩ.cm², respectively. [ABSTRACT FROM AUTHOR]

The principal goal of this research is to produce a CrN/Cu multilayer coating and a CrN single-layer coating and also compare their electrochemical and antibacterial behavior. In this investigation, the coatings were applied to the stainless steel substrate by cathodic arc evaporation a sub-division of physical vapor deposition (CAE-PVD). The present phases were characterized and the thickness of the coatings was measured using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM), respectively. Rockwell-C tester was used to evaluate the adhesion quality. Also, to evaluate the mechanical properties of the coatings such as modulus of elasticity and hardness, a nanoindentation test was used and the indentation effect and coating topography were evaluated using atomic force microscopy (AFM). Studying the electrochemical behavior of the coatings was done using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) tests in Ringer's solution. The results of EIS tests showed that the CrN coating had higher polarization resistance in comparison to the CrN/Cu coating and an increasing trend of polarization resistance related to both coatings was identified by rising the time of immersion. Also, using the PDP curves, the CrN and CrN/Cu coating current densities were estimated at 1.835×10-8 and 2.088×10-8, respectively. The antibacterial activity of CrN and CrN/Cu coatings was evaluated by the spot-inoculation method. The results of the antibacterial test indicated that compared to CrN coating, CrN/Cu coating had a better impact on the control of the bacteria growth. [ABSTRACT FROM AUTHOR]

The main purpose of this investigation was to assess the effect of post-deposition annealing treatment on the electrochemical behavior of TiN coating developed on AISI 304 stainless steel substrate using cathodic arc evaporation physical vapor deposition (CAE-PVD). Post-annealing treatment at 400°C was performed on the coated substrate for 1 h. The studied samples were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) tests. The preferred orientation of TiN (111) was verified by XRD patterns. The crystallinity of the coating was increased after annealing treatment. SEM observations indicated that TiN coatings free of cracks were developed on the substrate. The electrochemical measurements elucidated that the annealed coating had better corrosion resistance compared to that of the as-deposited coating with a lower current corrosion density. This investigation implies that improved corrosion performance of the TiN coating can achieved by performing post-deposition annealing treatment. [ABSTRACT FROM AUTHOR]