Anti-corrosion Film Research Articles

Adsorption and protective behavior of BTAH on the initial atmospheric corrosion process of copper under thin film of chloride solutions

The initial corrosion process of copper and the corrosion resistance mechanism of Benzotriazole under chloride-containing thin electrolyte layer (TEL) was investigated. After theoretical calculation and experimental characterization, the forming process of [Cu(I)BTA]n film was chemically adsorbed on copper surface by Cu-N bond tightly; corrosion rate increased as TEL thickness decreased. Whilst, energy distribution plot of electrochemical noise provided the validity of corrosion type, and the purported corrosion energy (Ec) deduced from electrochemical noise was approximately proportion to corrosion rate (1/Rct) with and without the anticorrosion film, which denoted the feasibility to determine corrosion rate by nondestructive on-line monitoring electrochemical noise progress.

Formation of Anticorrosive Film for Suppressing Pitting Corrosion on Al-Mg-Si Alloy by Steam Coating

Al alloys offer excellent physical and mechanical properties, such as a low density, high specific strength, and good ductility. However, their low corrosion resistance has restricted their application in corrosive environments. There is a need, therefore, for a novel coating technology that is capable of improving the corrosion resistance of Al alloys. In the present study, we examined a steam-based method of forming a corrosion-resistant film on Al alloys. Al-Mg-Si alloy was used as the substrate. The cleaned substrates were set in an autoclave with ultrapure water as the steam source and processed using different temperatures and holding times, resulting in the formation of anticorrosive films on the alloy. FE-SEM images of the film surfaces showed that plate-like nanocrystals were densely formed over the entire surface. XRD patterns indicated that the film was composed mainly of AlOOH crystals. The potentiodynamic polarization curves revealed that the corrosion current density of the film-coated substrates significantly decreased, and that the pitting corrosion was completely suppressed, indicating that the corrosion resistance of the Al-Mg-Si alloy was improved by the film formed by means of steam coating.

Application of protective coatings in combined electric diamond grinding

The article discusses the practical use of combined electro-discharge diamond grinding characterized by metal bond grinding wheel operation in a self-sharpening mode with minimal wheel consumption. The upgrading of grinding equipment technological capabilities at processing high-strength materials is possible due to the galvanic deposition of anti-friction and anti-corrosion films on the surfaces of the diamond wheel and the workpiece. These conditions facilitate the cutting process thereby increasing performance and the quality of the processed surfaces of machine parts. The application of this method provides the diamond wheels operation in self-sharpening mode and guarantees the continuity of its geometric shape which in turn ensures that no defective layer is formed on the treated surface and the cutting tools have longer efficient life.

Formation of Corrosion Resistant Mg(OH)2 Film Containing Mg-Al Layered Double Hydroxide on Mg Alloy Using Steam Coating

In recent years, a reduction in weight of materials is highly desirable in the fields of transport industry and information technology devices. Magnesium (Mg) alloys have excellent physical and mechanical properties such as low density, good electromagnetic shielding, and high strength/weight ratio. Unfortunately, they have a great issue that is low corrosion. Thus, it is very important to develop surface treatment technologies to improve the corrosion resistance of magnesium alloys. Many surface treatments such as chemical conversion, anodic oxidization, and electroplating have been developed. However, there processes require multi-step pretreatments and waste liquid treatments. Thus, the development of a simple, easy, and low-cost surface treatment is highly desirable. In this paper, we report a novel preparation method of anticorrosive film on Mg alloy by steam coating and the corrosion resistance of the film. The prepared films were characterized by XRD, SEM, EDX, and electrochemical measurements. Polarization curve measurements demonstrated that the Ecorr and icorr values were found to be most positive potential and lowest current density in all the samples, indicating that the sample had best corrosion resistant performance.

Room-Temperature Atomic Layer Deposition of Al2O3 for Anticorrosion Coating on Metal Surfaces

A room-temperature atomic layer deposition (RT-ALD) of Al2O3 as an anticorrosion coating for metal surfaces was developed using trimethylaluminum (TMA) and a plasma excited humidified argon. The schematic of ALD system is shown in Fig.1. TMA as the aluminum precursor was introduced with a mass flow controller. A remote plasma system generating excited humidified argon was installed to the ALD chamber. The source gas for the oxidizing gas is a mixture of water vapor and argon. The plasma was generated in a glass tube with an induction coil with a frequency of 13.56 MHz and a RF power of 100 W. For the Al2O3 deposition, we repeated the cycle of TMA saturation and oxidizing gas treatment at RT. The TMA exposure was set at 5.86×10-3 Torr×40 sec. The saturation of TMA on the hydroxylated surface was confirmed by the IR absorption spectroscopy. The plasma excited oxidizing gas was injected for 2 min. As a result, we show the anticorrosion test of ALD coated metal in a HCl solution. We used SUS430 plates with a size of 20×50×0.5 mm3 as the sample. In this test, we used a not-attenuated HCl solution with a concentration of 35 %. All the samples were immersed in the HCl solution for a certain amount of minutes at room temperature and we observed its surface coloring. Fig.2 shows a picture of the tested samples. The not-treated SUS430 sample clearly exhibits a white stain by the HCl corrosion. On the other hand, the Al2O3 coated sample maintained a mirror surface, which indicates that the RT-ALD coated film works as the anti-corrosion film against the acid solution. In the conference, we discuss the applicability of the RT-ALD to the anticorrosion coating for metal components. Acknowledgements This work was partly supported by JST-CREST, JSPS KAKENHI Grant Numbers 15H03536 and 15K13299. Figure 1

Corrosion resistance and characterization studies of calcium series chemical conversion film via green pretreatment on magnesium alloy

Purpose Magnesium alloys, although valuable, are reactive and require protection before its application in many fields. The purpose of this study was to evaluate a novel anticorrosive chemical conversion film on AZ80 magnesium alloy by environmental-friendly calcium series surface pretreatment. Design/methodology/approach The corrosion resistance of the film was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy in 3.5 Wt.% NaCl solution. The surface morphologies, microstructure and composition of the film were investigated by scanning electron microscopy and energy-dispersive spectroscopy. Findings The corrosion current density of the calcium series film decreased by more than one order of magnitude as compared to that of the AZ80 magnesium alloy. The conversion film presented dry-mud morphology, and its thickness was estimated to be approximately 4 μm. The conversion film was highly hydrophilic, and the organic coating adhesion on treated AZ80 surface was approximately 13.5 MPa. Originality/value Excellent performance of the calcium-based chemical conversion film on Mg alloy was obtained, which does not contain heavy metals or fluorides and completely conforms to European RoHS (Restriction of Hazardous Substances) standard.

Anti-corrosion film formed on HAl77-2 copper alloy surface by aliphatic polyamine in 3 wt.% NaCl solution

The corrosion inhibition of a polyamine compound, N-(4-amino-2, 3-dimethylbutyl)-2, 3-dimethylbutane-1, 4-diamine (ADDD), was investigated for HAl77-2 copper alloy in 3wt.% NaCl solution. Electrochemical measurements, scanning electron microscopy (SEM), atomic force microscope (AFM) and Fourier transform infrared spectroscopy (FT-IR) techniques were employed for this research. The results show that ADDD strongly suppresses the corrosion of HAl77-2 alloy. The inhibition efficiency of ADDD is 98.6% at 0.5mM, which is better than benzotriazole (BTAH) at the same concentration. Polarization curves indicate that ADDD is an anodic type inhibitor. Surface analysis suggests that a protective film is formed via the interaction of ADDD and copper. FT-IR reveals that the inhibition mechanism of ADDD is dominated by chemisorption onto the copper alloy surface to form an inhibition film. Furthermore, quantum chemical calculation and molecular dynamics (MD) simulations methods show that ADDD adsorbs on HAl77-2 surface via amino group in its molecule.

Diffusion of 1,2,3-Benzotriazole as a Volatile Corrosion Inhibitor through Common Polymer Films Using the Molecular Dynamics Simulation Method

ABSTRACTDiffusion of 1,2,3-benzotriazole (BT), as one of the volatile corrosion inhibitors (VCI) for copper and steel, through several polymers was investigated using molecular dynamics simulation (MD). MD were performed by employing the COMPASS force field to estimate the diffusivity of BT through polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and Nylon 6 as potential hosts for anticorrosion film packaging purposes. The diffusion coefficients (D) of BT in these polymers were calculated by constructing an amorphous cell, each containing BT and one of these polymers. After constructing the cell, a molecular dynamics simulation was performed to calculate the mean square displacement of the BT molecule. Simulation results showed that BT can diffuse through PVC easier than the other polymers. Among these hosts the Nylon 6 had the lowest D value, implying that this polymer can maintain BT for a long time. The temperature dependence of diffusion through PE, as the most common VCI film, was studied and the activation energy (Qd) and pre-exponential diffusion coefficient (D0) in Arrhenius equation were calculated.

Preparation and corrosion resistance of ZnO/CeO2 composite films

Zinc oxide/cerium oxide (ZnO/CeO2) composite films were fabricated on zinc surfaces by electrochemical oxidation at different current densities. Scanning electron microscopy and X-ray photoelectron spectroscopy were used to investigate the surface compositions and morphologies of the films. Corrosion resistance was analysed using polarisation curves, open-circuit potential and electrochemical impedance spectroscopy. The X-ray photoelectron spectra showed that the films were composed of ZnO and CeO2. Evaluation of corrosion revealed that the samples with composite films had lower corrosion rates. On the basis of these findings, ZnO/CeO2 composites have potential as anticorrosion films for zinc.

Growth Behaviors of Layered Double Hydroxide on Microarc Oxidation Film and Anti-Corrosion Performances of the Composite Film

Microarc oxidation (MAO) film has been widely used as an anti-corrosive film for Al alloys. However, it is still a big challenge to further improve its anti-corrosion performance due to the defects that form during the MAO process. In this study, for the first time, Ni-Al layered double hydroxide (LDH) was in-situ synthesized on the MAO film to seal its defects, which contributes to the corrosion resistance enhancement of MAO treated 6061 Al alloy. The growth of the LDH on MAO film is largely determined by the specific area, chemical composition, and crystalline structures of the alumina phase of the MAO film. More importantly, LDH nanoplates can grow into the micropores and microcracks in MAO film, and then gradually seal these structural defects. The anti-corrosion performance of MAO film during long-term immersion in NaCl solution also can be improved greatly via LDH treating because the defect-sealing effects of LDH can enhance the barrier property of both the porous and dense layers of MAO film, and then restrain the penetration of corrosive agents through the MAO film to the metal substrate.

Evaluation of Electrochemical Impedance Properties of Anticorrosion Films by Arc Thermal Metal Spraying Method

Evaluation of Electrochemical Impedance Properties of Anticorrosion Films by Arc Thermal Metal Spraying Method

적인 함유량에 따른 LDPE 수지 film의 특성연구

Due to tightened environmental regulations on halogen type flame retardants, the portions of those based on phosphorous compounds that are non-halogen type is rising. When producing functional film, the physical and thermal properties become distinctly different depending on the amount of Red-phosphorus(RP) addition which causes flame resistance. The physical properties of resin fall in big scale when too much flame retardants are added, and it is hard to be applied to functional films such as shrink or anticorrosive film. The purpose of this research is to study the effects on mechanical, physical, and other properties of RP-LDPE films by changing the RP-MB contents. The LDPE film used for this study was produced through blow-type injection molding. The flame resistance was VTM-0, and the tear resistance showed inverse trends of MD and TD. Contraction percentage showed no relationship with the amount of RP content, but the anti-corrosive property showed 0.05 % better result than the national anti-corrosion shrink film reliability standard.

Electrodeposition of Ni–GNS–TiO2 nanocomposite coatings as anticorrosion film for mild steel in neutral environment

In this article nanocomposites of graphene nanosheets–anatase titanium dioxide (GNS–TiO2) were prepared via hydrothermal method. In this method graphene oxide (GO) was reduced to graphene nanosheets (GNS) simultaneously with anatase (TiO2) growth in situ on the graphene nanosheet (GNS) surface. The resulting GNS–TiO2 nanocomposite was characterized using X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR). The percentage of TiO2 in the prepared GNS–TiO2 was determined by thermo gravimetric analysis technique (TGA). The fabricated GNS–TiO2 nanocomposite was codeposited with Ni by electrodeposition technique and used as a protective film for mild steel used in construction of steel silos. Different operating conditions for the deposition process were adopted to obtain Ni–GNS–TiO2 nanocomposite coatings with good morphological properties. The Ni–GNS–TiO2 nanocomposite coatings were characterized using a field emission scanning electron microscope (FE-SEM) and energy dispersive X-ray analysis (EDX). Moreover, Ni–GNS–TiO2 nanocomposite coatings were subjected to different electrochemical and mechanical tests to evaluate their corrosion behavior and hardness in comparison with that of pure Ni coating. It was found that the corrosion rate of the Ni–GNS–TiO2/mild steel electrodes decreases and the microhardness increases with increasing the wt.% of GNS–TiO2 nanocomposite in the prepared electrodes. The best corrosion resistance value of 33.1kΩcm2 and relatively high hardness value of 478HV were recorded for the composite coating electrode that contains 20.4wt.% GNS–TiO2 compared with the other composite coating electrodes or pure Ni coatings.

Influence of organic corrosion inhibitors on the corrosion performance of organic–inorganic hybrid coatings applied on aluminium alloy

The proposed work aims to develop and study sol–gel derived anticorrosion films for aluminium. To further improve performance of these films, organic corrosion inhibitors were incorporated into the films. The organic–inorganic hybrid films with and without corrosion inhibitors were deposited on an aluminium substrate by dip coating. The films were characterized by electrochemical impedance spectroscopy (EIS), DC polarisation techniques, and neutral salt spray test to evaluate their anticorrosion properties. This study shows that very low and very high MBT concentrations deteriorate the corrosion performance of coatings, and consequently, there is an optimum concentration of MBT. EIS results revealed a higher corrosion inhibitive activity of 2-mercaptobenzothiazole (MBT) compared to that of 2-amino-5-methylthiazole and 1,2,3 benzotriazole.

The Structural Stability of Graphene Anticorrosion Coating Materials is Compromised at Low Potentials

Corrosion of engineered structures is a major problem causing an estimated economic loss of more than 2 trillion US dollars annually worldwide. Graphene has recently emerged as highly promising, low-cost, and transparent anticorrosion coating material. Herein, it is shown that a multilayer graphene film grown on Ni by chemical vapor deposition undergoes abrupt stability failure under galvanic-corrosion conditions. The multilayer graphene coating was examined by optical microscopy, SEM, energy dispersive X-ray spectroscopy, Raman spectroscopy, and cyclic voltammetry after exposure to potentials between 600 and 1300 mV in alkaline solution. A fast and simple electrochemical method is proposed to sensitively quantify the damage caused by the applied potential bias. It is based on quantification of the oxidation signals generated by the underlying Ni-metal catalyst that is exposed by damage to the graphene film. It is shown that film damage can start at potentials as low as 900 mV and that macroscopic and extensive damage can be caused at potentials above 1000 mV. In addition, once the graphene film has been damaged, the corrosion rate of the underlying metal is significantly increased. These findings are of great importance for potential applications of multilayer graphene films in coating metal structures with huge industrial and economic implications.

Plasma Enhanced Electrochemical Preparation for Photo-Luminescent Metal Oxide Films on Al Foil

Electrochemical coating technologies of metal surface have been widely used for decades in various industries, because it provides the thick and anti-corrosive films with a simple and cheap process [1]. Especially, plasma electrolytic oxidation (PEO), which is a high electrical power-induced technology, has much attention in recent years due to their excellent film property. The PEO produces adherent ceramic-like coatings, which are beneficial to enhance the corrosion and wear resistance, so the oxidized film can be applied in many industrial fields [2-4]. During PEO process, a high–voltage discharge zone is generated with spark or arc plasma micro-discharge, and the thick ceramic coating is directly formed on the surface of metals together with elements in the electrolyte. At the discharge zone, the extreme environments with high temperature and pressure are generated, and estimated temperature is around 8000 K at a hot core and 1800 K at a cold circumferential area [5]. In this study, we applied the plasma discharge phenomenon in PEO process to generate the photo-luminescent oxide film by adding the rare-earth ions in the electrolytes, and the white light emitting oxide film was successfully formed on aluminum foil. So far, the luminescent film was fabricated by screen printing technique, combustion CVD, spin coating, sol-gel soft lithography, and radio-frequency magnetron sputtering, but those kinds of phosphor films showed many problems such as poor uniformity of film thickness and low adhesion to the substrate [6-8]. In case of PEO process, the rare-earth ions are directly incorporated during oxidation process, so well adhesive luminescent films can be obtained. In order to prepare photo-luminescent oxide film, the plasma electrolytic oxidation of Al foil was conducted in rare-earth ion containing base electrolyte with constant current density of 3 A/dm2 using DC pulse power supply. Various electrolytes and rare earth ions were employed and their effects on the photoluminescence properties of the obtained films were examined. To find out the correlation of photo-luminescence and micro arc generation in early stage, cathode-luminescence properties were investigated in the films formed around break-down voltage with SEM images. When europium was present in the electrolyte, a white light emitting ceramic-like film covering from NUV to visible was formed on aluminum foil (Fig. 1). The film was mainly composed of γ-Al2O3, and the emission spectrum consisted of two emission peaks centered at 420 nm and 500 nm with a broad FWHM (~197.6 nm). The origin of these emission peaks will be discussed in this presentation. In addition, the effects of electrolyte composition and rare-earth ions on the phase content and photoluminescence properties of the Al2O3films will be presented.Reference[1] G. Helen Annal Therese and P. Vishnu Kamath, Chem. Mater.,12, 1195 (2000)[2] A. Kuhn, Met. Finish, 101, 44 (2003)[3] X. Nie, E. I. Meletis, J. C. Jiang, A. Leyland, A. L. Yerokhin, and A. Matthews, Surf. Coat. Technol., 149, 245 (2002)[4] C. Blawert, W. Dietzel, E. Ghali, and G. Song, Adv. Eng. Mater., 8, 511 (2006)[5] A. L. Yerokhin, X. Nie, A. Leyland, A. Matthews, and S. J. Dowey, Surf. Coat. Technol., 122, 73 (1999)[6] K.Y. Jung, Y.C. Kang, Mater. Lett, 58, 2161 (2004)[7] Z.T. Kang, Y. Liu, B.K. Wagner, R. Gilstrap, M. Liu, C.J. Summers, J. Lumin., 121, 595 (2006)[8] W.-H. Chao, R.-J. Wu, T.-B. Wu, J. Alloys Compd., 506, 98 (2010)

Mechanism of (NH4)S2O8 to enhance the anti-corrosion performance of MoCe inhibitor on X80 steel in acid solution

Abstract Ce(NO3)3 and Na2MoO4 are adopted to form (Mo Ce) composite corrosion inhibitor in allusion to the corrosion problem of steel in acidic conditions. The experimental results showed that the anticorrosion effects were enhanced and the inhibition efficiencies were increased by (NH4)2S2O8. The reason of enhancement is the increase of coordination bonds amount between Ce4+ and Mo O 4 2 − , the augment of combining sites of interface between anti-corrosion film and steel, and the reinforce of adsorption caused by the transformation of Ce3+ to Ce4+ by oxidants. The process and conditions for transformation of Ce3+ to Ce4+ and formation of complexes are discussed. The related thermodynamic and kinetic parameters are calculated and the possibility for (NH4)2S2O8 to improve the performance of Mo Ce corrosion inhibitor is proved.

Repairable mesoporous silica film with replenishing corrosion inhibitor as corrosion protection layer of aluminum alloy

Cetyltrimethylammonium bromide (CTAB) encapsulating mesoporous silica (MS) film shows strong corrosion protection property for aluminum alloy in NaCl solution. The corrosion protection capability of the MS film is reversible upon calcination or long term service and the replenishing with corrosion inhibitors. Replenishing the MS film with a quaternary ammonium bromide is molecular size selective. The corrosion protection capability of the replenished MS film is enhanced by increasing the carbon chain length of the ammonium molecule. The replenishing technique ensures the MS film as a repairable anti-corrosion film and extends its service life. The strong corrosion protection property of the MS film is attributed to its lowly porous structure and hydrophobic nature.

GS-2 コンクリート防食用GFRP皮膜の硫酸・有機酸混合環境下での劣化挙動(一般セッション)

GS-2 コンクリート防食用GFRP皮膜の硫酸・有機酸混合環境下での劣化挙動(一般セッション)

Organic–inorganic hybrid sol–gel pretreatments for corrosion protection of mild steel in neutral and acidic solutions

This work aims to develop and study sol–gel-derived anticorrosion films for mild steel. Epoxy bis-silane precursor has been prepared by reaction of liquid epoxy resin and aminopropyl triethoxysilane. A pretreatment application bath (Sol) has been prepared by dissolving epoxy-silane precursor at constant solid content and fixed water/ethanol ratio, and the solution was adjusted to acidic pH. The organic–inorganic hybrid films were deposited on mild steel by dip-coating technique, by immersion of sample panels into the sol and their withdrawal at controlled rate to facilitate the desired and uniform film. Films were subsequently cured at room temperature. The anticorrosion properties of the coatings were studied using electrochemical impedance spectroscopy, DC polarisation techniques and neutral salt spray test. This study shows that very dense and protective hybrid coatings on mild steel can be obtained by controlling the resin/silane ratio during synthesis of the precursor.