In this paper, nanostructured CrAlN Coatings were deposited onto steel substrates using an industrial cathodic arc physical vapor deposition (Arc-PVD) technique. Field emission scanning electron microscopy (FESEM) was employed to evaluate the microstructure and the phase analysis was carried out using Energy Dispersive Spectroscopy (EDS) and Xray diffraction (XRD) methods. The XRD patterns were used to determine the crystallographic texture of the Coatings and the results showed (222) as the dominant texture. Moreover, it was found that all Coatings had nanocrystalline structure with crystallite sizes between 8-18 nm. CrN was found to be the dominant phase in the XRD patterns; addition of aluminum produced CrAlN, leading to shifts of the diffraction peaks. Cr2N and AlN phases were identified by the XRD pattern which can be attributed to the decrease of the nitrogen pressure down below a critical value and the increase in the evaporation of aluminium, respectively. The change in the Al content of the coating and the subsequent displacement of the diffraction lines caused a challenge in the phase identification procedure. Therefore, identifying the existing phases in the coating was not feasible merely by the EXPERT software since CrAlN is not defined in its database; the crystal phase data of the nitride Coatings must be used for accurate phase identification.

This research is intended to cover the creation of Multilayer nanostructured titania coating on 304L stainless steel by sol-gel dip-coating method to study the effect of thickness and Multilayer characteristic on the photocatalytic properties of this coating. A stable polimeric sol based on Titanium Tetraisopropoxide with diethanolamine as additive was used in the coating process and by repeated immersion process, coating samples with 1 to 5 layers were prepared using two methods, one stage heat treatment and multistage heat treatment. To investigate the properties of samples, following analysis methods are used; TG, DTA,, XRD, SEM, AFM, surface roughness test and photocatalytic tests under UV and VIS irradiation. Analysis results of XRD, SEM and AFM showed nanometric scale of TiO2 particles in the coating samples. No evidence of discontinuity has been detected during cross section area examination of multi-layer Coatings using SEM. The analysis results of DTA, TG and XRD showed the formation of crystalline anatase phase from the amorphous phase at temperatures around 350oC, then anatase to rutile phase transformation begins at 500oC, and finally completes at 700oC. The optimal temperature for heat treatment was determined as 450oC which is also confirmed by the results of photocatalytic tests. The effect of thickness and layer numerity on the photocatalystic propeties of cotings is one of the discovered results in this research. From the point of photocatalytic properties, the optimum thickness of titania coating was determined around 198nm, which belonged to 3-layers coating with three stage heat treatment. The average surface roughness (Ra) in Multilayer coating samples with multistage heat treatment has been decreased from 0.107 mm in one layer sample to 0.0147mm in five layer sample, when layer numbers increased.

In this paper, the performance of the cutting tool with nanocrystalline Multilayer Coatings (TiN+TiAlN) for machining of superalloy Inconel 718 in the dry and wet conditions was studied. The multi layer TiN and TiAlN with nanocrystalline structure was applied by physical vapor deposition technique (arc evaporation) on the WC-Co inserts. The results of the ball on disc wear test and the machining of superalloy Inconel 718 in wet and dry conditions indicated that the nanocrystalline Coatings could produce better performance of tools in turning. Abrasion and adhesive wear resistance improved by nanocrystalline and modified Aluminum composition in TiAlN coating as well as toughness and thermal stability.

In this paper, we reviewed researches about the titanium nitride (TiN) and titanium carbide (TiC) single and Multilayer Coatings. These Coatings were deposited by the plasma assisted chemical vapor deposition (PACVD) technique. Plasma-based technologies are used for the processing of thin films and Coatings for different applications such as automobile and aerospace parts, computer disc drives, food industry and surgical/medical instruments. We describe the state of the performance of different coating systems and thin film architectures in PACVD suitable for industrial-scale or laboratory applications. Mechanical properties of Coatings such as wear resistance, hardness and the scratch resistance, structural characteristics, physical and chemical properties like Coatings adhesion into different substrates, wetting behavior and corrosion resistance were studied. Thus, this paper represents a source of information for those who want to familiarize with the status of knowledge in the area of materials science of functional Coatings, in particular TiN/TiC Coatings that was deposited by a new Plasma-based technologies.

In this paper, corrosion behavior of single and Multilayer (TiN, CrN and TiN/CrN) deposited Coatings on Ni-Cr dental alloy in artificial saliva using cathodic arc evaporation-physical vapor deposition (CAE-PVD) technique were investigated. The corrosion behavior of uncoated and coated Ni-Cr prosthetic dental alloy has been investigated electrochemically in addition to the other way represented by the quantity measurement of corrosion products which is resulted from the Ni-Cr dental alloys. Fusayama artificial saliva has been utilized as media for measuring all electrochemical behaviors. The surfaces of samples have been analyzed using X-ray diffraction (XRD), energy dispersion spectroscopy (EDS), and scanning electron microscopy (SEM). The results indicated that the coating procedure that has applied to Ni-Cr dental alloy may change wettability by decreasing the hydrophilicity of the surface. The results indicated that the strongest hydrophobic character is exhibited by CrN coating. Potentiodynamic polarization and Nyquist plots showed that CrN coating had an exceptionally high polarization resistance compared to Ni-Cr dental alloy, TiN and TiN/CrN Coatings.

Die casting process is used since long, but even today problems like erosion, corrosion, soldering and sticking affect die life. These dies undergo thermal cyclic loads from 70 oC to 600 oC during processing. Physical Vapor Deposition (PVD) hard coating can play an important role in such extreme applications. In the present work, we report the use of Chromium based Multilayer CrN/Cr (M-CrN) Coatings and multicomponent aluminium titanium based AlTiN (M-AlTiN) Coatings. The H-13 steel substrate samples were prepared using cathodic arc deposition technique. Structural properties of the coated samples were studied using XRD and SEM techniques. Tribological and mechanical properties of the Coatings were studied using Calo-test and Micro-hardness test respectively. Potentiostat technique was used to study the effect of 1 M HCl solution on these Coatings. Thermal fatigue (TF) test was conducted by heating the sample to around 600 oC and rapidly cooling it to room temperature imitating the die casting process conditions. After multiple cycles, it was observed that M-AlTiN coated samples outperform M-CrN coated samples in terms of wear, oxidation and adhesion properties. It was observed that formation of oxide layer on the coated surface during the thermal cycling inhibits further oxidation of the coating layer and result in enhanced productivity and efficiency of dies.

In this investigation, Ti/TiN nanolayer and TiN single layer Coatings were coated on substrate of AISI 316L stainless steel by applying physical vapor deposition (PVD) using the type of cathodic arc evaporation (CAE). The evaluation of microstructure were carried out using x-ray diffraction (XRD), nanoindentation, atomic force microscopy (AFM) as well as scanning electron microscopy (SEM). Polarization and impedance tests were utilized to study the Coatings corrosion behavior in the simulated body solution (SBF) in different immersion times. Utilizing CAE technique, high density and adhesion Ti/TiN nanolayer and TiN single layer Coatings were successfully made. The corrosion results showed that Ti/TiN nanolayer coating had an exceptionally high polarization resistance compared to 316L substrate and TiN single layer coating. Furthermore, the corrosion results indicated the desired corrosion behavior in the nanolayer coating towards the single layer within the SBF, as a result of the distinct layers presence resulting in a barrier against penetration of the corrosive media.

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.

Surface treatments of the biomaterials are of great interest in many biomedical applications,Hydroxyapatite is a favorable candidate for surface modification of the implants,To date,a wide variety of methods have been developed to produce bio-active/biocompatible Coatings with desirable features in order to improve the performance of the implants,This paper strives to overview the present prevalent methods for synthesizing the hydroxyapatite based Multilayer Coatings as well as the various properties of such Coatings,The common methods for fabrication of HAp-containing Multilayer Coatings including electrochemical,sol-gel,and plasma spray routs,It was clearly highlighted that the main drawback in pure HAp Coatings is their poor adhesion to the implants,The studies in the field of HAp-ceramic systems showed that the deposited ceramic layers,e,g,TiO2 and ZrO2,are strongly adherent to HAp and substrate which leads to a remarkable improvement in the mechanical properties of pure HAp Coatings,Unlike HAp-ceramic systems,there are less studies dealt with the HAp-polymeric systems,The performed studies demonstrated that the corrosion resistance and adhesion strength of the Coatings to the substrates can be considerably improved with the deposition of HAp/polymer Multilayer Coatings,Altogether,HAp based Multilayer Coatings have bright prospect since they benefit from HAp biocompatibility as well as the enhanced adhesion to the substrate,