Showing papers in "Journal of Bio- and Tribo-Corrosion in 2019"

Mechanical, Moisture Absorption, and Abrasion Resistance Properties of Bamboo–Jute–Glass Fiber Composites

Abstract: Composites have been shown to be commendable alternates to many traditional materials for use in many load-bearing engineering applications. Besides their superior corrosion resistance, composite materials also offer the maximum scope for weight reduction due to their great strength and lower density. In this experimental study, composites of natural fibers (jute and bamboo) and reinforced glass fiber were developed by a hand layup method and their mechanical properties, water absorption resistance, and abrasion responses evaluated as per ASTM standards and compared in dry versus wet conditions. The results show that such use of jute and bamboo fibers with glass fiber-reinforced polymer (GFRP) can result in good mechanical properties, wear resistance, and moisture absorption resistance, representing a good substitute material for GFRP. Composites are generally used in diverse applications including housing, roofing, packaging, automobile industry, etc., and materials such as those described herein could help improve rural economies.

Polymeric-Based Epoxy Cured with a Polyaminoamide as an Anticorrosive Coating for Aluminum 2024-T3 Surface: Experimental Studies Supported by Computational Modeling

Abstract: The present research focused on a coating formulation for aluminum surface 2024-T3 to protect it from corrosion. The formulation consisted of a polymeric epoxy resin-coated bisphenol A diglycidyl ether (DGEBA) cured with a polymeric polyaminoamide. The coated aluminum 2024-T3 was tested in a harsh environment of electrolyte solution (3 wt% NaCl solution) to simulate the harsh marine environment. The coated sample was evaluated by Electrochemical Impedance Spectroscopy (EIS). Under these conditions, a very high impedance (Z) value was obtained; even after exposure for a period longer than 4392 h, the performance was still acceptable. Surface morphological study of metallic specimens before and after exposures to the simulated marine environment (3 wt% NaCl) was carried out using scanning electron microscopy (SEM). The results indicate that the DGEBA-polyaminoamide (DGEBAAA) performed as an excellent barrier for Al surface. The results were combined by several modeling approaches involving molecular dynamics simulation (MD), Monte Carlo methods (MC), and the electronic density functional theory (DFT) computations to explore the adhesion forces between the DGEBAAA and the aluminum surface. The computational MD, MC, and DFT studies were executed in aqueous media. Computational results further evidenced the stronger DGEBA-aminoamide adhesion onto the aluminum 2024-T3 even in a wet environment.

Surface Modification Methods for Titanium and Its Alloys and Their Corrosion Behavior in Biological Environment: A Review

Abstract: Titanium (Ti) and its alloys are being used in biomedical field owing to their low elastic modulus, good fatigue strength and formability, and corrosion resistance. However, they are still not sufficient for long-term clinical usage as they are bio-inert and they cannot bond to living bone directly at the early stage after implantation into a human body. Their surfaces play an important role in response to the artificial devices in a biological environment; for these materials to meet the clinical demands, it is necessary to modify their surface. The corrosion resistance and biological properties of Ti and its alloys can be improved selectively by using the appropriate surface modification techniques while the desirable bulk attributes of the materials are retained. The proper surface treatment expands the use of these materials in the biomedical field. This article reviews the various surface modification techniques for Ti and its alloys including mechanical methods, chemical and electrochemical treatment, thermal spraying, sol–gel, and ion implantation towards the field of biomedical engineering. A positive effect of various surface modification techniques is illustrated in this review as suggested by many research groups. Also, this article includes the corrosion behavior of surface-modified Ti and its alloys for biomedical applications.

An Investigation into Quantum Chemistry and Experimental Evaluation of Imidazopyridine Derivatives as Corrosion Inhibitors for C-Steel in Acidic Media

Abstract: The corrosion inhibition performance of two imidazopyridine derivatives, namely 6-nitroso-2-phenylimidazo[1,2-a]pyridine-3 carbaldehyde (C1) and (2-phenylimidazo[1,2-a]pyridin-3-yl)methanol (C2) for carbon steel in 1.0 M hydrochloric acid solution, was evaluated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and quantum chemical calculations. The surface morphology was examined using Scanning Electron Microscopy (SEM). Imidazopyridine derivatives adsorbed onto the carbon steel surface via mixed types of adsorption with predominantly chemisorption obeying Langmuir adsorption isotherm. DFT computational chemistry at B3LYP/6-31G(d,p) basis set level was applied in order to correlate some electronic properties of tested molecules to the inhibition efficiencies obtained from experimental data. The computed Fukui functions have been useful to predict the reactive sites of nucleophilic and electrophilic attacks.

Corrosion Inhibition of Ordinary Steel in 5.0 M HCl Medium by Benzimidazole Derivatives: Electrochemical, UV–Visible Spectrometry, and DFT Calculations

Abstract: In the present work, a new organic inhibitor, namely (2(-4(chloro phenyl-1H-benzo[d]imidazol)-1-yl)phenyl) methanone (CBIPM), that has an inhibitive effect on the ordinary steel corrosion in 5.0 M HCl has been studied using electrochemical measurements (potentiodynamic polarization and electrochemical impedance spectroscopy). The obtained results showed that the inhibition efficiency increased with concentration and reached 98.6% at 10−3 M. In addition, the CBIPM takes its performance at the temperature range of 298–328 K. The adsorption of the inhibitor on the ordinary steel was well described by the Langmuir isotherm. On the other hand, the establishing of correlation between the molecular structures of quantum chemistry indices was carried out using the density functional theory.

Evaluation of Anti-biofouling Progresses in Marine Application

Abstract: Biofouling is detrimental and has been a major concern in the marine industry for several decades. This phenomenon is the accumulation, colonization and attack of organisms—which are both micro and macro, to assemblies, parts and/or structures that are submerged in freshwater and other marine environments. Even despite all the exceptional indispensable and indisputable characteristics of alloys such as steel, biofouling continues to be a major source of failures of these alloys, thereby limiting their use in service. This study presents a review of the existing means of protection against biofouling which are basically the use of paints and electrolytic deposition of anti-biofouling agents such as some nano-composite coatings. The different types of systems from the first-generational coatings such as tributyltin self-polishing copolymer paints to the novel nano-composite coatings were discussed. Ultimately, the use of nano-materials and composites consisting some anti-biofouling natural products has identified to be a promising way of combating biofouling issues in the maritime.

Molecular Dynamics, Monte-Carlo Simulations and Atomic Force Microscopy to Study the Interfacial Adsorption Behaviour of Some Triazepine Carboxylate Compounds as Corrosion Inhibitors in Acid Medium

Abstract: Molecular dynamic, Monte-Carlo simulation approach and electrochemical methods were used to study the temperature effects on mild steel (MS) corrosion in 1.0 M of HCl in the absence and presence of triazepine carboxylate compounds. The inhibition action of all triazepine carboxylates compound studied was performed via adsorption on MS surface. Comparison between several adsorption isotherms reveals that the adsorption was spontaneous and followed Langmuir isotherm in HCl for all inhibitors and at all studied temperatures. Furthermore, selection is founded on the correlation coefficient is known nearly linear and value close to one. Kinetic and thermodynamic parameters for all inhibitors led to suggest the occurrence of chemical mechanism and also the spontaneity of the adsorption process on mild steel surface. The corrosion inhibition mechanism was discussed with the light of some triazepine carboxylate compounds constituents. The effect of molecular structure on the inhibition efficiency has been explored by quantum chemical computations and obvious correlations were observed. The binding energies of tested triazepine carboxylate compounds on Fe (110) surfaces were calculated using molecular dynamics simulation. Very good agreement was obtained with the experimental data. In addition, Atomic force microscopy (AFM) indicated that Cl–Me–CN molecules contributed to a protective layer formation by their adsorption on the steel surface. AFM parameters, such as root mean square roughness (Rq), average roughness (Ra), and ten-point height (Sz), revealed that a smoother surface of inhibited mild steel was obtained, compared to uninhibited steel surface.

Effect of 1,3,4-Thiadiazole Scaffold on the Corrosion Inhibition of Mild Steel in Acidic Medium: An Experimental and Computational Study

Abstract: The optimal inhibition efficiency of DBTA (4-Dimethylamino-benzylidene)-[1, 3, 4]thiadiazol-2-yl-amine) for MS (mild steel) in 1.0 M hydrochloric acid solution was achieved through employing electrochemical impedance spectroscopy (EIS) and weight loss techniques in addition to Scanning Electron Microscopy (SEM). Theoretical calculations based on Density functional theory (DFT) method were carried out for DBTA. Investigations of the mechanism for the corrosion inhibition for MS with DBTA in acidic solution by molecular simulations were performed. The results demonstrated that DBTA is an excellent corrosion inhibitor for MS in corrosive solution, and the inhibitory effectiveness was 91%, much higher than that expected at the highest concentration of DBTA. Spontaneous process of adsorption of DBTA on the mild steel surface was proved based on Langmuir adsorption isotherm.

An Investigation on Mechanical and Wear Characteristics of Al 6063/TiC Metal Matrix Composites Using RSM

Abstract: This paper focuses on the consequences of reinforcement content (TiC particles) on sliding wear behavior of aluminum alloy Al 6063 fabricated by stir casting process. Three different reinforcement percentages (5, 10 and 15) have been considered in the present study. Both hardness and tensile tests have been executed on the fabricated samples. The results of the conducted mechanical tests showed that the increase in reinforcement weight percent increased the tensile strength and hardness. Pin-on-disk tests have been performed on the fabricated composite samples to identify their tribological behavior. Reinforcement weight percent, load and sliding speed with three levels each were taken as the process variables, and specific wear rate is considered as response. Box–Behnken design have been utilized to carry out the experiments and to analyze the results. Moreover, ANOVA is carried out to know the influencing parameter on the response. From ANOVA, it was confirmed that reinforcement weight percent and sliding speed is considered as the influencing parameters on the response.

Electrochemical and Tribological Behavior of Surface-Treated Titanium Alloy Ti–6Al–4V

Abstract: To enhance its low wear resistance, a surface treatment of ion nitriding was performed for Ti–6Al–4V titanium alloy. Structural characteristics of specimens were revealed by optical and scanning electron microscopy, and tribological behavior was evaluated using ball-on-disk tribometer by application of two different charges 5 N and 10 N. Electrochemical methods of potentiodynamic polarization curves and electrochemical impedance spectroscopy were used to evaluate the effect of this thermochemical treatment on the corrosion resistance of the studied alloy. Results showed that microhardness of nitrided Ti–6Al–4V represents a value greater with four, five times than that of the untreated alloy. The coefficient of friction was also optimized for the two charges applied. SEM analysis of the worn surfaces indicates that the wear of treated Ti–6Al–4V stills just superficial. However, electrochemical tests show that corrosion resistance of titanium alloy deteriorates after plasma nitriding.

Electrochemical Studies on New Pyridazinium Derivatives as Corrosion Inhibitors of Carbon Steel in Acidic Medium

Abstract: Two pyridazine derivatives “1-decylpyridazin-1-ium iodide” (DPI) and “1-tetradecylpyridazin-1-ium iodide” (TPI) were synthesized and investigated as corrosion inhibitors for carbon steel in HCl (1 M) solution. In order to evaluate the anticorrosion activity of these compounds, the electrochemical impedance spectroscopy was performed at different concentrations and at various temperatures (303–333 K). The collected results showed that DPI and TPI reached a value of 86.7% and 88.6% at 10−3 M, respectively (303 K). The decrease of the double-layer capacitance for TPI became more remarkable with increase in temperature. The adsorption of both inhibitors on mild steel surface obeyed the Langmuir adsorption isotherm. An inhibition efficiency of 97.6% was obtained at the optimum concentration (10−3 M) following an immersion period of 12 h. The quantum chemical calculations based on DFT method supported the experimentally obtained results.

Synthesis and Characterization of New Triazole Derivatives as Corrosion Inhibitors of Carbon Steel in Acidic Medium

Abstract: Six novel triazole derivatives were synthesized from some substituted benzoic acid with thiocarbohydrazide by grinding method. The synthesized compounds were characterized by infra-red, 1H, and 13C-NMR spectra investigations. Synthesized triazole derivatives were tested and evaluated as corrosion inhibitors for low-carbon steel in 0.5 M HCl using weight loss technique. It was found that these compounds had a promising inhibitory action against corrosion of mild steel in acidic solution. Inhibitor with highest performance was evaluated at different temperature and inhibitor concentrations. The inhibition efficiency exceeded 96%. The excellent inhibitor performance was attributed to the formation of inhibitor adsorption films on the steel surface. The adsorption of inhibitor on steel surface followed the Langmuir adsorption isotherm. The experimental results were confirmed via theoretical quantum chemical calculations.

Effect of Corrosion on Crude Oil and Natural Gas Pipeline with Emphasis on Prevention by Ecofriendly Corrosion Inhibitors: A Comprehensive Review

Abstract: This paper focuses on the problems faced by oil and gas industries due to corrosion during refining and its transportation and to overcome with this problem by use of appropriate inhibitor. Different sources of energy requires transmission from one area to another and this should be efficient, effective and for this we use pipelines which are made of different metallic equipments which generally faces problem of corrosion. The mechanism of corrosion, its different types encountered in oil and gas industries are mentioned. Impact of corrosion on economics such as capital cost, design cost, control cost and associated cost are illustrated. Different types of physiochemical parameters that are responsible for initiation and acceleration of corrosion are discussed. Various techniques used for determination of corrosion rate and concept of corrosion allowance is discussed. This paper describes corrosion inhibitors, types of inhibitors and their selection criteria. This paper gives brief review of various types of eco-friendly inhibitors such as different types of amino acids, various classes of drugs, rare earth materials such as lanthanides. Their advantages and limitations are also discussed.

Corrosion Mitigation of Aluminium in 3.65% NaCl Medium Using Hexamine

Abstract: This study reports the performance of Hexamine as a useful corrosion inhibitor on Aluminium alloy in 3.65% NaCl at ambient temperature and a constant pH of 7. The corrosion-protective ability of Hexamine was investigated utilizing potentiodynamic polarization procedures, computational studies and mass loss estimates. The result from the research unveils that Hexamine hinders the corrosion of Aluminium alloy in sodium chloride solution. The inhibition effect was due to the blockage of the active site of the metal surface by the adsorbed molecule of Hexamine thereby forming a thin layer which minimizes the intrusion of chloride ion into the mobile sites of Aluminium alloy, leading to the reduction of corrosion current density. The deteriorations in mass by the inhibited Aluminium alloy were discovered to decrease as the mass of mass concentration of Hexamine increases. The outcome of the experiment indicated that Hexamine offered inhibition performance of 47.1%, which may likely increase as mass concentration increases. Polarization curve confirmed that Hexamine in 3.65% NaCl at ambient temperature behaved as a mixed-type inhibitor, reducing the corrosion rate and increasing the polarization potential. Adsorption of Hexamine molecules on the Aluminium alloy was attested to follow Langmuir adsorption isotherm with correlation regression coefficient (R2) value of 0.8408. The Morphology study via SEM micrograph affirms the adsorption of Hexamine molecules on the surface of the Aluminium alloy.

Thiazole Ionic Liquid as Corrosion Inhibitor of Steel in 1 M HCl Solution: Gravimetrical, Electrochemical, and Theoretical Studies

Abstract: The ionic liquid namely 3-((4-amino-2-methylpyrimidin-5-yl)methyl)-5-(2-hydroxyethyl)-4-methylthiazol-3-ium chloride (AMPMHMC) was used as a corrosion inhibitor to protect carbon steel against 1 M HCl solution. The corrosion behavior was investigated by chemical and electrochemical techniques. The results showed that the inhibition efficiency increased with increase in the concentration (10–40 ppm) of the inhibitor and the maximum inhibition efficiency reached 91.4% at concentration 40 ppm. The adsorption of the inhibitor on carbon steel surface obeyed the Langmuir’s adsorption isotherm. Surface analysis of the carbon steel was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results further demonstrated that the AMPMHMC was a promising environment-friendly inhibitor with effective inhibition efficiency.

Enhanced Corrosion Properties of Nanostructured 316 Stainless Steel in 0.6 M NaCl Solution

Abstract: Surface modification through surface mechanical attrition treatment (SMAT) process and annealing were employed to enhance the corrosion properties of 316 stainless steel (SS) in 0.6 M NaCl. SMAT resulted in the formation of a nanocrystalline layer on 316 SS with an average grain size of 20 nm at the depth of about 30 µm from the treated surface. The nanocrystalline microstructure of the surface was characterized by X-ray diffraction and scanning electron microscopy. The micro-hardness of the surface layer of the treated sample was higher than that of the as-received sample by about 100 HV (Vickers hardness) at a depth of 200 µm from the treated surface. By the combined effect of SMAT and low-temperature annealing treatment at 400 °C, the electrochemical tests revealed an improvement in the corrosion properties of 316 SS in terms of corrosion potential and current density. This was attributed to the easy movement of Cr from the material matrix to the surface layer which resulted in the formation of a protective oxide layer on the material surface.

A Review on the Assessment of Imidazo[1,2-a]pyridines As Corrosion Inhibitor of Metals

Abstract: Imidazo[1,2-a]pyridines find great importance in several commercially available drugs but recently, this derivative has been reported as effective corrosion inhibitors due to their excellent excited state intra-molecular proton transfer which elevates the performances of their adsorption into the metallic surface. In this paper, we have reported a review of some works that investigated the effects of some imidazo[1,2-a]pyridine molecular on corrosion inhibition properties applying different techniques. They reported that the adsorption of this derivative into the steel surface follows the Langmuir isotherm making a strong bond sometimes and linked with physical adsorption another time. The theoretical method and SEM technique have also been reviewed for some molecular inhibitors.

Inhibitive Performance of Ibuprofen Drug on Mild Steel in 0.5 M of H2SO4 Acid

Abstract: The search for eco-friendly inhibitors has necessitated the use of inhibitive drugs in the control of corrosion in aggressive environments. This work examines the adsorption effect of Ibuprofen drug as on mild steel in H2SO4 environment using polarization method. The Ibuprofen drug was administered in the proportion of 0, 5, 10, 15, and 20 ml. The adsorption studies unveiled that as the Ibuprofen drug concentration increases, the inhibition efficiency of the inhibited samples increases. The result shows that the inhibitive drug offered some degree of protection on the steel in the corrosive medium. The inhibitor efficiency was above 60%. The adsorption of the inhibitive drug was found to obey Freundlich isotherm law with correlation regression coefficient of R2 = 0.9676. The closeness of R2 to unity establishes the reliability of Ibuprofen drug as inhibitor.

Inhibition Efficiency of Cinnamon Oil as a Green Corrosion Inhibitor

Abstract: The corrosion inhibition efficiency of cinnamon oil for stainless steel 304 L in 0.1 and 1.0 M HCl solutions was investigated using electrochemical study and surface electronic observation. The potentiodynamic polarization curves showed that, independently of the time of immersion in 1.0% HCl, a reaction to the anode occurred, which was explained by the dissolution of the metal due to the strong aggressiveness of the medium; the addition of 1% cinnamon oil led to a corrosion efficiency of 84%. Furthermore, in 0.1 M aggressive medium the tests with addition of inhibitor showed that the inhibition efficiency increases (86.6–96.0%) with an increase in the cinnamon oil concentration from 0.5 to 5%. Scanning electron microscope observations of metal surface confirmed the existence of a protective adsorbed film of the inhibitor on the steel surface. Cinnamon oil can be proposed as an efficient green inhibitor of corrosion of stainless steel exposed to hydrochloric acid mediums.

The Role of Zinc Phosphate Pigment in the Anticorrosion Properties of Bisphenol A Diglycidyl Ether-Polyaminoamide Coating for Aluminum Alloy AA2024-T3

Abstract: This study is focused on an anticorrosive formulation as a coating an aluminum alloy AA2024-T3 to withstand marine environment. The anticorrosive formulation was based on an epoxy resin bisphenol-A diglycidyl ether that is cured with polyamine polyaminoamide. The anticorrosive formulation was applied onto samples of AA 2024-T3 surface with zinc phosphate (ER-ZP) and without zinc phosphate (standard). Zinc phosphate was added to the formulation in about 5 wt%. The coated AA2024-T3 substrates were evaluated by exposing them to a salt spray test chamber for various periods of time. The anticorrosive performances of the two epoxy coatings, the standard (ER) and the one containing ZP (ER-ZP), were evaluated by electrochemical impedance spectroscopy (EIS). The surface morphology of the two coatings was characterized by a scanning electron microscopy and optical microscopy. The two coated AA2024 T3 samples were tested in a harsh environment of electrolyte solution to simulate the marine environment (3 wt% NaCl solution). The value of the impedance (|Z|0.01 Hz) obtained by the EIS method for the standard epoxy coating (ER) and epoxy coating containing ZP (ER-ZP) were 0.88 MΩ cm2 and 6.92 MΩ cm2 during the 2 h of immersion in 3 wt% NaCl, respectively. After exposure for a long period of time in salt spray test chamber (4392 h) and 2 h of immersion in 3 wt% NaCl the values were dropped to 0.27 MΩ cm2 and 0.83 MΩ cm2, respectively. Under these conditions, a very high impedance value was obtained for AA2024-T3 samples coated with an epoxy coating containing ZP (ER-ZP). The results showed that, the ER-ZP coating surface applied on AA2024-T3 samples exposed for 4392 h showed that, the coating is homogeneous and well adhered to aluminum alloy 2024-T3 surface. The results indicated that, ZP played a dual role, it enhanced the adhesion properties of the ER coating and the coating performance as an effective barrier.

Corrosion Inhibition and Adsorption Properties of Mild Steel in 1 M Hydrochloric Acid Medium by Expired Ambroxol Drug

Abstract: The inhibitive action of an examined expired Ambroxol (AB) drug on the corrosion of mild steel in 1 M hydrochloric acid medium has been studied by both weight loss and electrochemical techniques. The weight loss techniques result was discussed. The inhibition efficiency increases with increasing the concentration of the AB inhibitor. Electrochemical studies data support that examined expired AB drug is an efficient inhibitor for mild steel in 1 M hydrochloric acid medium. The adsorption of the examined drug obeys Langmuir’s and Temkin adsorption isotherm. Polarization studies indicate that this inhibitor acts as a mixed mode of inhibition. The various thermodynamic parameters were calculated and discussed. The protective film formed on the surface was confirmed by FTIR, SEM and EDS. The quantum-chemical calculation also supports the inhibitive effect of the inhibitors. The data collected from the studied techniques are in good agreement to confirm the ability of using expired Ambroxol (AB) drug as corrosion inhibitor for mild steel in 1 M hydrochloric acid medium.

An Experimental and Theoretical Study of Biodegradable Gemini Surfactants and Surfactant/Carbon Nanotubes (CNTs) Mixtures as New Corrosion Inhibitor

Abstract: Inhibition performance of noncovalent functionalization of carbon nanotubes (CNTs) with biodegradable gemini surfactants on mild steel surface in 2 M hydrochloric acid solution was examined by potentiodynamic polarization, electrochemical impedance spectroscopy and quantum chemical calculations. Ultraviolet–visible (UV–vis) spectroscopy, thermogravimetric analysis, Raman analysis, and zeta-potential (Z-potential) measurements are also applied to discuss the stability of studied solutions. Ester-containing cationic surfactants; monomeric betainate, dodecyl esterquat gemini (ET), and dodecyl betainate gemini (BT) were used as potentially superior noncovalent functionalization agents for CNT-based formulations. For the first time, the anticorrosive efficiency of these surfactants on mild steel was investigated. The noncovalent functionalization of CNTs with ester-containing surfactants showed more appropriate inhibition properties at higher surfactant concentrations as a result of further dispersing ability. The best inhibition efficiency (IEE = 93%) is reported for BT (2.5 mM)-suspended nanotubes, while the effectiveness is decreased (IEE = 12%) dramatically at low concentration (0.1 mM). Surface observations are also employed to verify the corrosion protection of mild steel covered with noncovalent functionalization of CNTs. Density functional theory was employed for quantum chemical calculations, and a good correlation between experimental data and theoretical data has been obtained.

Magnesium-Based Bioresorbable Stent Materials: Review of Reviews

Abstract: Many materials proposed as bioresorbable. However, in the clinical cardiology practice, they are not often used. This study evaluates the mechanical and corrosion properties of magnesium-based bioresorbable materials and identifies barriers to their implementation in clinical practice. The Embase, Scopus, Springer Link, and Science Direct databases searched up to April 4th, 2018. The magnesium-based materials were classified according to the compound materials used for enrichment. We have summarized the mechanical and corrosion properties separately. Of the 4194 potentially relevant publications, 101 reported systematic reviews. Of these studies, we included 37 in our review of reviews. In 51% of reviews, the authors reported mechanical properties and in 40% corrosion properties.

Anticorrosive Formulation Based of the Epoxy Resin–Polyaminoamide Containing Zinc Phosphate Inhibitive Pigment Applied on Sulfo-Tartaric Anodized AA 7075-T6 in NaCl Medium

Abstract: The addition of zinc phosphate pigment to standard epoxy coatings has been investigated as an anticorrosive and eco-friendly additive. In this study, we prepared two epoxy coatings without and with zinc phosphate for corrosion protection of AA7075-T6 substrates for different time exposures in NaCl solution. The two epoxy coatings were evaluated by electrochemical impedance spectroscopy and their surfaces were characterized by scanning electron microscopy. The results show that the addition of zinc phosphate to the anticorrosive formulation (epoxy resin–polyaminoamide) facilitated the formation of a barrier film, enhanced the barrier anticorrosive properties of the coatings and therefore inhibited the penetration of aggressive corrosive ions to the AA7075-T6 surface.

Corrosion in Crude Distillation Overhead System: A Review

Abstract: The consequence of corrosion in the oil and gas industry cannot be ignored due to the damage caused to equipment and structures, and the huge cost of controlling it. This review covers the corrosion of metallic structures, types of corrosion that occurs, and corrosion prevention and control in crude distillation overhead system. Some case studies on crude distillation overhead system, the economic cost of corrosion within the oil and gas industry and the factors responsible for corrosion in crude distillation overhead system are discussed. Corrosion has been a major challenge in the oil and gas industry, especially in the crude distillation overhead system where the metallic structure used for construction and equipment are majorly affected by corrosion. However, to minimize corrosion cost in oil and gas industry, application of corrosion inhibitors and appropriate material selection is of utmost importance as stated in this report. Materials selected are mostly affected by general corrosion or localized corrosion, depending on the metallurgical properties of the material used.

Engineered Synthetic Diamond Film as a Protective Layer for Tribological and Machining Applications: A Review

Abstract: Cobalt-based tungsten carbide composite (WC-Co, with different grades) is the commonly used material for cutting tools and tribological components, because of its high hardness and high wear and corrosion resistance. The carbon fiber-reinforced plastics (CFRP) and Al-SiC metal-matrix composites (MMCS) are materials mostly used in aerospace and automobile industries due to their high strength-to-weight ratio. During the machining of these composite materials, the conventional WC-Co cutting tools are subjected to high abrasive wear because they contain constituent hard reinforced particles. Thus, these types of machining applications need super-hard coatings for better performance and durability. Nowadays, synthetic diamond coatings obtained by chemical vapour deposition (CVD) process play an important role in improving the performance of the carbide tools while machining these composite materials, because of their superior mechanical and tribological properties. CVD diamond coatings with good wear resistance, super hardness, and low friction coefficient are in demand for industrial applications. But, the main problem of these diamond coatings is the coating de-lamination under high mechanical loads experienced during the machining process. Presently, researchers concentrate on the improvement of the coating adhesion for their better performance. However, to achieve the desired synthetic diamond coating for industrial applications many characteristics of the coating-substrate system need to be considered like good adhesion, optimum coating thickness, and minimum thermal residual stresses. Therefore, the microstructure and architecture of the synthetic diamond coatings should be adjusted to achieve the basic practical requirements like high wear resistance, high hardness, enough adhesion strength, and low friction coefficient.

Pitting Corrosion Behavior of F304 Stainless Steel Under the Exposure of Ferric Chloride Solution

Abstract: Present paper deals with an experimental investigation of pitting corrosion of forged 304 stainless steel. Material is exposed to ferric chloride solution to investigate the effect of pitting corrosion. This material is known to provide structural strength with improved toughness and ductility. A number of experiments were carried out on F304 SS under ferric chloride solution by putting it for three different time durations of 8 h, 16 h, and 24 h. The results specify that pit formation increases over time. During experimentation, the number of pits, pit depth, corrosion rate, weight loss, and average pit depth have been measured. Microstructural characterization and surface roughness tests were carried out on the chemically exposed surface to understand the growth of pitting corrosion. Fractographic images high-end microscopy showed that the ferric chloride solution initiates the pitting of 304 austenite stainless steel. Furthermore, the exposure leads to the formation of a number of small pits that coalescence together to form cracks that appear at the bottom of the pit. It was also confirmed that the appearance of small bottom pits initiates cracks by increasing the duration of corrosion test to 24 h which is only due to dissolved inclusive atoms of chloride as revealed by EDX analysis.

Extraction, Characterization and Anticorrosion Potential of an Essential Oil from Orange Zest as Eco-friendly Inhibitor for Mild Steel in Acidic Solution

Abstract: Current research efforts now focus on the development of novel, cheaper, nontoxic, highly efficient and eco-friendly corrosion inhibitors as alternatives to different inorganic and organic compounds. In this context, orange zest essential oil (OZEO) was investigated as corrosion inhibitor for mild steel in 1 M HCl medium utilizing different techniques such as gas chromatography–mass spectrometry (GC–MS), mass loss, electrochemical and scanning electron microscope (SEM) associated with energy-dispersive X-ray spectroscopy (EDX). The obtained results indicated that this OZEO acted as an efficient corrosion inhibitor and the inhibition efficiency reached up to 75.64% at 2.5 g L−1 of OZEO. The potentiodynamic curves revealed that OZEO acted as mixed inhibitor with a predominantly anodic action, facilitating the formation of an adsorbed film over the mild steel surface. The adsorption data is fitted to Langmuir, Flory–Huggins, Freundlich, El-Awady, Temkin, Frumkin, Langmuir–Freundlich and Dubinin–Radushkevich isotherms models and involve chemisorption mechanism. SEM examination and EDX analysis of the mild steel surface confirmed the existence of a protective adsorbed film.

Some New Nonionic Surfactants Based on Propane Tricarboxylic Acid as Corrosion Inhibitors for Low Carbon Steel in Hydrochloric Acid Solutions

Abstract: The effect of some new nonionic surfactants namely, N1,N2,N3-tris ((14-amino-3,6,9,12-tetraazatetradecyl) carbamothioyl) propane-1,2,3-tricarboxamide (compound I) and N1,N2,N3-tris((2-hydroxyethyl) carbamothioyl) propane-1,2,3-tricarboxamide (compound II) for the corrosion of low carbon steel (LCS) in 1.0 M HCl was evaluated by electrochemical and non-electrochemical techniques. From weight loss measurements, the concentration of these compounds and the temperature of the medium have a large effect on the inhibition efficiency (IE%). The IE% reached 93% for compound (I) and 77.7% for compound (II) at 75 ppm. The behavior of these compounds obeys the Temkin isotherm with good fitting. Polarization curves of these surfactants indicate that they affect both anodic metal dissolution and cathodic H2 evolution (i.e. mixed type). The action of the addition of these compounds on the LCS was detected using scanning electron microscopy, energy disperse X-ray, Fourier-transform infra-red (FTIR) spectroscopy and atomic force microscopy (AFM) techniques. Electrochemical and non-electrochemical methods gave matched results.

Tribocorrosion of Porous Titanium Used in Biomedical Applications

Abstract: Titanium and its alloys have become increasingly important in the dental and orthopedic fields due to its good machinability, high yield strength, good ductility, excellent corrosion resistance, and superior biocompatibility compared to other materials. However, an inherent drawback of using pure titanium and its alloys as implant material is the significant mismatch between the moduli of bone and titanium, resulting in the stress shielding effect, fibrous tissue ingrowth, and bone resorption, and therefore reducing the lifespan of the implant. Porous titanium is thus a suitable candidate as implant material due to its ability to be manufactured to a specific Young’s modulus—typically that of bone. Porous titanium has the unique advantage of allowing bone tissue ingrowth into the open space of the implants, thereby accelerating the osseointegration process. The human body as well as the oral cavity is a highly complex environment in which the simultaneous interaction between wear and corrosion, namely tribocorrosion, takes place. Thus, understanding these interactions is of great interest in order to characterize the degradation mechanisms of porous titanium materials used as implants. This paper reviews the state-of-the-art of porous titanium as a viable biomedical implant material. A significant part of this paper is focused on how porous titanium is manufactured and how its parameters are controlled. The following sections focus on the corrosion, wear, and tribocorrosion aspects of porous titanium implant materials. Finally, this review also determines the current limitations in the field and provides future directions in this field.