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The purpose of this paper is to investigate improving high‐temperature oxidation resistance of titanium by developing new coatings based on aluminum and its combination with the substrate. Nanocrystalline plasma electrolytic saturations were applied on the surface of commercially pure titanium in an aqueous bath. The aim was to obtain good corrosion and oxidation resistances of the differently treated samples by investigation of their nanostructures. The advantages of developed new coatings and the necessity of their use in modern gas turbine engines allow the metals to be used safely at high temperatures, which in turn can enhance the efficiency of gas‐turbine engine‐compressor sections.

The electrolytic saturation process was done in an aqueous bath with different effective parameters such as frequency, peak of applied pulsed voltage, etc. to obtain the desired nanostructures. Systematic characterization was carried out on as‐prepared as well as oxidized coatings and these results are presented. The performance of new coatings was evaluated by generating weight‐gain data as a function of time, followed by detailed characterization in order to confirm the ability of the coatings to prevent oxidation and alpha‐case formation. Potentiodynamic polarization and SEM nanograph analysis were undertaken to study corrosion resistance and the nanostructure of obtained layers.

The results showed that the corrosion and oxidation resistance of the obtained layers depended strongly to the average size of nanocrystallites and their nanomorphology. All coated samples had better electrochemical and oxidation behavior compared to the untreated substrate.

The results obtained in this research into nanocrystalline plasma electrolytic saturation can be used wherever good corrosion and oxidation resistances with high efficiency are required.

The speed of treatment by this technique makes this method very suitable for industrial surface treatment of different components.

The purpose of this paper is to investigate the effect of thermal treatment at low partial pressure of oxygen on electrochemical corrosion resistance of Ti‐47Al‐2Cr (at %) intermetallic, known as γ‐TiAl alloy.

The surfaces of the samples were modified by thermal treatment at different temperatures in N₂ gas flow for an hour. Characterization of the modified surface layers was carried out by microscopic examinations, hardness and roughness tests, and X‐ray diffraction analyses. Potentiodynamic polarization was used to evaluate the corrosion performance of γ‐TiAl in Ringer's solution.

The results indicated that the alloy treated at 950 °C had the optimum corrosion resistance, which can be attributed to the formation of an oxide layer by the surface thermal treatment and increase of the passive layer thickness.

Low corrosion rate (CR), high pitting potential (Epit), and more noble corrosion potential (Ecorr) make it possible for γ‐TiAl to be considered as a candidate for biomedical applications.

The treatment described in the paper is a novel method for surface modification of this type of alloy and results showed that it was an effective treatment and that the corrosion resistance improved remarkably.

Uniform nanostructured TiO₂ thin film has been applied as an over coat on micro‐arc oxidized substrate, using the sol‐gel method. The anticorrosion performance of the coating have been evaluated using electrochemical techniques. Owing to increasing application of light alloys in industry, the purpose of this paper is to report effort to increase the corrosion and wear resistance properties of these alloys by applying a TiO₂ nanostructured coating using the sol‐gel method on the micro‐arc oxidation (MAO) surface. This approach will decrease the time for the MAO process, especially for achieving good mechanical properties, and will minimize energy consumption as well as achieving better results from the obtained coatings.

Sol‐gel coatings were deposited (on titanium substrates) by spin coating techniques. The morphologies and nanostructures of thin films were analyzed using scanning electron microscope, atomic force microscopy and grazing incidence X‐ray diffraction (XRD). The anticorrosion performance of the coating has been evaluated by using electrochemical techniques. Tafel polarization measurements provide an explanation for the increased resistance of nanostructured TiO₂ coated specimen against corrosion. Effective sol‐gel coating parameters were optimized with respect to this enhancement. Electrochemical impedance spectroscopy measurements showed the role of barrier layer on corrosion resistance of MAO and nanostructured TiO₂ coating.

The results showed that i_corr is decreased from 0.258 to 0.169 (μA/cm²). An optimized TiO₂ nanostructured coating with thickness of 74 nm will shift the open circuit potential (OCP) about 165 mV and will improve the corrosion prevention properties of coated samples. Corrosion resistance by these duplex coatings can be improved by a factor of more than three times, compared to that of the uncoated substrate. Increasing the coating thickness to more than 74 nm will decrease the physical and corrosion properties of coated samples. It can be concluded that samples with the optimized coating showed higher values of charge transfer resistance, due to the presence of a newly formed layer that accounted for the greater corrosion protection.

The results obtained in this research into nanostructured coating can be used wherever good corrosion and wear resistances are required.

The speed of treatment by this technique makes this method very suitable for industrial surface treatment of different components.

The aim of this paper is to obtain optimal corrosion resistance of certain differently treated samples by investigation of their electrochemical properties.

Nanocrystalline plasma electrolytic carbonitriding (PEC/N) treatments were applied on the surface of commercially pure titanium in a glycerol bath with different additives. The carbonitriding process was performed in a glycerol bath with different additives such as carbamide, natrium nitrate and triethanolamine. The effects of electrolyte composition on chemical composition and corrosion resistance of the PEC/N films were examined by means of X‐ray diffraction, scanning electron microscopy, potentiodynamic polarization and electrochemical impedance spectroscopy in a Ringer solution.

The results showed that the PEC/N films obtained in solutions with triethanolamine (T‐film) had better corrosion resistance. All coated samples had a better electrochemical behaviour compared with the untreated substrate. Different nano‐structures and morphologies were obtained by different additives in electrolyte.

The results obtained in this research into nanocrystalline PEC/N can be used wherever good corrosion and wear resistance with the highest efficiency is required.

The speed of treatment by this technique makes this method very suitable for the industrial surface treatment of different components.

The low resistance against penetration of water, oxygen and the other corrosive ions through the paths of coating is one the most important problems. So, protective properties of coating such as polyester must be promoted. Recently, the use of nanoparticles in the matrix of polymer coating to increase their protection and mechanical properties has been prospering greatly. The purpose of this study is to improve the corrosion resistance of the polyester powder coating with ZnO nanoparticles. The ZnO nanoparticles have been synthesized by hydrothermal method in a microwave. Using polyester – ZnO nanocomposite coating as powder – combining them by ball milling process and coating them by electrostatic process are innovative ideas and have not been used before it.

Polyester powder as the matrix and ZnO nanoparticles as reinforcing were combined in three different weight percentage (0.5, 1, 2 Wt.%), and they formed polymer nanocomposite by ball milling process. Then, the fabricated nanocomposite powder was applied to the surface of carbon steel using an electrostatic device, and then the coatings were cured in the furnace. The morphology of synthesized zinc oxide nanoparticles was investigated by transmission electron microscope. Also, the morphology of polyester powder and fabricated coatings was studied by scanning electron microscope. The effects of zinc oxide nanoparticles on the corrosion resistance of coated samples were studied by electrochemical impedance spectroscopy (EIS) test at various times (1-90 days) of immersion in 3.5 per cent NaCl electrolyte.

Scanning electron microscopy (SEM) results reveal that there are no obvious crack and defects in the nanocomposite coatings. In contrast, the pure polyester coatings having many cracks and pores in their structure. According to the EIS results, the corrosion resistance of nanocomposite coating compared to pure coating is higher. The value obtained from EIS test show that corrosion resistance for coating that contains 1 Wt.% nanoparticle was 32,150,000 (Ωcm²), which was six times bigger than that of pure coating. In addition to providing a barrier against diffusion of electrolyte, ZnO nanoparticles act as a corrosion inhibitor and, thus, increases the corrosion resistance. The corrosion resistance of coating containing 0.5 Wt.% nanoparticles was lower as compared to that of 1 Wt.% nanoparticles. The low content of nanoparticles caused partial covering of the porosity of coating which in turn leads to provide weaker barrier properties. The increase in quantity of nanoparticles from 1 to 2 Wt.% also caused a decrease in corrosion resistance which is attributed to the agglomeration of nanoparticles.

The results of this study indicated the significant effect of ZnO nanoparticles on the protective performance and corrosion resistance of the polyester powder coating. Evaluation of coating surface and interface with SEM technique revealed that nanocomposite coating compared with pure polyester coating provided a coating with lower number of pores and with higher quality. The EIS measurements represented that polymeric coating that contains nanoparticles compared to pure coating provides a better corrosion resistance. In addition to providing a barrier against diffusion of electrolyte, ZnO nanoparticles act as a corrosion inhibitor and thus increase the corrosion resistance. The corrosion resistance of coating containing 0.5 Wt.% nanoparticles was lower as compared to that containing 1Wt.% nanoparticles. The low content of nanoparticles caused partial covering of the porosity of coating which in turn leads to provide weaker barrier properties. The increase in quantity of nanoparticles from 1 to 2 Wt.% also caused a decrease in corrosion resistance which is attributed to the agglomeration of nanoparticles.

Plasma electrolytic saturation (PES) treatments were applied on the surface of AISI H13 steel and corrosion resistance of the treated samples was investigated using electrochemical test methods. The aim was to obtain optimal corrosion resistance of the differently treated samples.

Nitrocarburized and boride layers were produced on AISI H13 steel by the means of the PES technique. Different experimental parameters during each treatment provided different microstructural and electrochemical properties. The techniques used in the present investigation included X‐ray diffraction, SEM, potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS).

The plasma electrolytic nitrocarburising coating was characterized by lower integrity than a PEB coating. All PES coated steels had a noble electrochemical behavior compared to the untreated steel. Different nano‐structures and morphologies obtained by different experimental parameters produced different electrochemical behaviors.

The results obtained in this research into PES techniques can be used wherever good corrosion resistance with the highest efficiency is required.

The speed of treatment by plasma electrolytic saturation techniques makes this method very suitable for industrial production of components.

This paper aims to evaluate the efficacy of a zeolite-filled silane sol–gel coating as protective layer on pretreated AZ31 magnesium alloy substrates.

Anti-corrosion properties of a silane–zeolite composite coating, at various zeolite content, have been investigated on AZ31 magnesium substrates subjected to different surface pretreatment procedures before coating deposition. A short time etching by hydrofluoric acid (HF) and an anodic polarization in NaOH solution were used as surface pretreatments.

High hydrophobicity and good adhesion performances of coatings have been observed. Corrosion protection performance, during immersion in 3.5 per cent NaCl solution, was evaluated by means of electrochemical impedance spectroscopy tests. All coating formulations evidenced good barrier properties. Better durability properties have been shown by coating obtained on HF pretreated magnesium substrate and with a 60 per cent of zeolite content.

High electrochemical reactivity of magnesium alloys represents the mayor limit of its application in many different fields. In this concern, zeolite-based coatings are emerging as potentially effective environmentally friendly coating for metallic substrates. Despite aluminum and stainless steel substrates, in the literature, only expensive direct synthesis zeolite coating was investigated for its application on magnesium alloys protection. For this reason, this paper fulfills the need to assess the adhesion and anti-corrosion behavior of sol–gel silane–zeolite coating in magnesium alloy substrates.

SiO₂ and SiO₂-ZrO₂ nanocomposites were coated by sol–gel dipping method on carbon steel 178 (178 CS). Nanostructure and phase properties of nanocomposite coating were characterized using X-ray diffraction, scanning electron microscopy and Fourier transform infrared studies. Electrochemical polarization and electrochemical impedance spectroscopy (EIS) tests were used to study the corrosion behavior of 178 CS that was coated with SiO₂-ZrO₂ nanocomposite and SiO₂ coating in 3.5 per cent NaCl solution. The results indicated that SiO₂-ZrO₂ nanocomposite coating performed better in terms of corrosion resistance compared with SiO₂ coating. The corrosion resistance of SiO₂-ZrO₂ nanocomposite coating could be increased significantly in by approximately three and seven times of that of SiO₂ coating and bare 178 CS, respectively.

SiO₂ and SiO₂-ZrO₂ nanocomposites were coated using sol–gel dipping method on carbon steel 178. Electrochemical polarization and EIS tests have been used to study the corrosion behavior of 178 CS that was coated with SiO₂-ZrO₂ nanocomposite and SiO₂ coating in 3.5 per cent NaCl solution.

Results indicated that SiO₂-ZrO₂ nanocomposite coating performed better in terms of corrosion resistance compared with SiO₂ coating. The corrosion resistance of SiO₂-ZrO₂ nanocomposite coating could be increased significantly in by approximately three and seven times of that of SiO₂ coating and bare 178 CS, respectively.

The SiO₂-ZrO₂ nanocomposite coating film showed significant improvement in corrosion resistance of 178 CS. The highest polarization resistance of the nanocomposite coating film was 10,600 Ω/cm² from SiO₂-0.2 ZrO₂.

This study aims to review the current one-step electrodeposition of superhydrophobic coatings on metal surfaces.

One-step electrodeposition is a versatile and simple technology to prepare superhydrophobic coatings on metal surfaces.

Preparing superhydrophobic coatings by one-step electrodeposition is an efficient method to protect metal surfaces.

Even though there are several technologies, one-step electrodeposition still plays a significant role in producing superhydrophobic coatings.

This paper aims to achieve an anti-corrosive coating via uniform dispersion of nanoclay particles (montmorillonite) and polypyrrole (PPy) as a conductive polymer as well as their effects on the anti-corrosion features in the presence of the eco-friendly ionic liquids (ILs).

In this research, PPy with different forms of nanoclay were used. Moreover, ILs additive is used to enhance the better dispersion process of clay and PPy nanoparticles in the resin.

As a result, the IL additive in the formulation of nano-composite coatings greatly improves the dispersion process of clay and PPy nanoparticles in the resin. Due to its high compatibility with polyurethane resin and clay and PPy nanoparticles, this additive contains a high dispersing power to disperse the investigated nanoparticles in the resin matrix.

High polarity of ILs as well as abilities to dissolve both mineral and organic materials, they can provide the better chemical processes compared to common solvents.

IL abilities have not been discovered to a large extent such as catalysts and detectors.

ILs have been emerging as promising green solvents to replace conventional solvents in recent years. They possess unique properties such as nonvolatility, low toxicity, ease of handling, nonflammability and high ionic conductivity. Thus, they have received much attention as green media for various chemistry processes.

The simultaneous existence of clay, PPy and IL additive in the nano-composite coating formulation is responsible for the high corrosion resistance of the coating.