Corrosion Of Aluminum Research Articles

An investigation of microstructural basis for corrosion behavior of Al-CNT composites fabricated by SPS

In this research effect of the addition of multi-wall carbon nanotubes (MWCNTs) as additive powder on microstructure and corrosion behavior of fabricated Al-CNT composites was studied. The aluminum powder and CNTs were mixed with high energy planetary ball-mill. It is observed that by increasing milling time, the uniformity of CNTs on aluminum matrix and consequently corrosion resistance of Al-CNT composite is increased. On the other hand, by increasing the volume percentage of CNTs, the uniformity of CNTs on aluminum matrix and corrosion resistance of fabricated Al-CNT composite is reduced. The value of polarization resistance, Rp, for fabricated composites with 2 % CNT is improved from 1.28 to 3.60 Ω/cm2 by increasing milling time. Also, the value of Rp for fabricated composites with 4 h milling time, is reduced from 3.60 to 2.76 Ω/cm2 by increasing the percentage of CNTs from 2 % up to 5 %. Moreover, Cyclic Polarization results showed that the pitting corrosion resistance improves by increasing milling time and deteriorates by increasing the percentage of CNTs. The electrochemical impedance spectroscopy (EIS) results showed that the corrosion mechanism of Al-CNT composites is a combination of uniform and pitting corrosion. Indeed, the CNTs act as preferred cathode regions and cause to formation of micro galvanic couples. The Al-2%CNT-4 h showed better uniformity and the highest corrosion resistance. The Al-5%CNT-2 h presented non-uniform distribution of CNTs and the lowest corrosion resistance.

Hydrogen production through aluminium corrosion in a cement‐based matrix

AbstractIn France, deep geological disposal is considered for the storage of high and intermediate‐level long‐lived radioactive wastes. For aluminium, the possibility to encapsulate the wastes in a cement‐based matrix is studied. However, cement being an alkaline environment, aluminium can lose its passivity, starts to corrode leading to hydrogen evolution in the infrastructures and generate a possible explosive hazard after decades of storage if hydrogen can accumulate somewhere in the facility. It is therefore necessary to study the corrosion behaviour of aluminium in the different cements considered for the encapsulation to estimate the possible amount of hydrogen that could be generated through corrosion and design the cement capsules accordingly. This work mainly focused on the reaction occurring at the aluminium‐cement interface. Raman spectroscopy did not highlight significant differences in the nature of the corrosion products forming at the cement/aluminium interface, leading to the conclusion that it is not the chemistry of the cement that is the key factor controlling the corrosion rate but rather the physical properties of the cement matrix.

Tribo-corrosion resistance of Ti-Nb-Cr-Mo-Al refractory high-entropy alloys in molten aluminum

Ti40Nb25Cr15Mo10Al10 and Ti40Nb20Cr20Mo10Al10 refractory high-entropy alloys (RHEAs) were designed and fabricated, aiming at investigating their mechanical properties, corrosion and tribo-corrosion behavior in molten aluminum. Compared with H13 steel, these RHEAs exhibit significantly better combinations of high-temperature mechanical properties, corrosion and tribo-corrosion resistance. Low solubility of constituent elements in molten aluminum along with slow diffusion of Al atoms in RHEAs’ matrices, are responsible for the outstanding corrosion resistance of RHEAs. Exceptional tribo-corrosion resistance of RHEAs derives from their outstanding combinations of corrosion resistance and high-temperature mechanical properties. Additionally, higher content of Cr in RHEAs would lead to worse tribo-corrosion resistance.

Effect of anodizing on aluminum alloy 2024 with boric sulfate acid in medium 3.5 % NaCl

The utilization of metal materials finds widespread applications in various industries, including the aircraft industry, where aluminum alloys are commonly employed. However, metal materials are prone to corrosion under specific conditions, necessitating the implementation of corrosion prevention methods to decelerate the material's corrosion rate. Corrosion is a process in which the quality of metal deteriorates due to environmental influences. An effective approach to inhibit corrosion is through anodizing, which involves applying a protective coating to the metal surface, preventing direct contact with the surrounding environment. In this research, the focus was on studying the corrosion rate of aluminum alloy 2024 using Boric Sulfate Acid Anodizing (BSAA) at 10 volts and immersion times of 10, 15, and 20 minutes, followed by sealing with acetic acid in a corrosive environment containing 3.5 % NaCl. The main goals were to evaluate the effectiveness of anodizing with and without sealing in lowering the rate of aluminum corrosion, to compare the effectiveness of anodizing with and without sealing, and to create adsorption models using Langmuir adsorption. Through the examination of the potentiodynamic approach, it was shown that anodizing had an inhibitory impact that was strengthened by sealing. The maximum efficiency of 76 % was attained after 20 minutes of anodizing and sealing at 10 volts. A correlation value of 0.7487 from the Langmuir adsorption modeling was also obtained, pointing to an advantageous adsorption behavior. This research demonstrates how effectively anodizing for aluminum alloy 2024 works with and without sealing, especially in a 3.5 % NaCl-corrosive environment

Predicting Galvanic Corrosion of Aluminum Using Accelerated Laboratory Electrochemical Experiments

Aluminum (Al) alloys are the most commonly used non-ferrous metals (approximately 25 million tons per year) for various technical applications and is the second most commonly used metal alloy after steel. Al alloys are also used in combination with other metals or materials to get specific desirable properties for applications such as transportation, construction, electrical appliances, and consumer goods. However, a system of dissimilar materials can lead to potential corrosion problems such as galvanic and crevice corrosion. In this work, atmospheric galvanic corrosion of Al alloy was predicted by combining electrochemical techniques and accelerated laboratory corrosion tests. Three different galvanic couples were analyzed where 6061-T6 Al alloy was coupled with a passivating metal (304 stainless steel), noble metal (copper), and a carbon fiber-reinforced polymer matrix composite (CFR PMC). The galvanic current flowing between the anode and cathode was measured using the zero-resistance ammeter (ZRA) technique in the humidity-chamber setup, cyclic corrosion test chamber following a modified GM9540P cycle, and an outdoor exposure test site. Electrolytes with varying amounts of chloride contents were used to simulate different atmospheric conditions. Four separate equations based on Faraday's law were developed to calculate the corrosion rate in grams per meter square per day (gmd) by relating the time of wetness (TOW) to the galvanic current measured from the accelerated laboratory experiments. The total exposure time was divided into wet periods (Twet) and dry periods (Tdry). The surface morphology of Al samples from the galvanic couples was studied using a scanning electron microscope (SEM), and elemental surface analysis was conducted using energy-dispersive X-ray Spectroscopy (EDXA). Figure 1

Evaluation of protection performances of novel synthesized bis-oxindole-based derivatives for the corrosion of aluminum in acidic environment

Three bis(3-schiff base-indoline-2-one) derivatives, 3(a-c), and two bis-spirotriazole-indole derivatives, 5(a,b), were synthesized and were evaluated as inhibitors for the corrosion of Al in 1.0 M HCl at 303 K. Weight loss (WL) method was applied for evaluation of the inhibition efficiencies (% IEs) of all synthesized compounds while WL in addition to potentodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) were employed in case of the compound that has the highest% IE values. The collected results illuminated that the synthesized compounds were discovered to be efficient inhibitors and their% IEs were set to vary with their concentrations, structures, and the corrosive medium concentration. WL outcomes revealed that, the order of% IEs of the synthesized compounds was: 5a ≈ 5b > 3a > 3b ≥ 3c. The acquired high% IEs of such compounds were attributed to their potent adsorption on the Al surface and production of a protective film, and this adsorption was agreed with Langmuir adsorption isotherm. The kinetics of corrosion inhibition by the synthesized compounds appeared a negative-first order process confirming the gained higher values of% IEs of such compounds. PDP results indicated that the compound 5a behaves as a mixed inhibitor with a cathodic majority. The results acquired from the three utilized tools were set to be in a good agreement with each other's confirming the validity of the obtained results.

Eco-Friendly Methanolic Myrrh Extract Corrosion Inhibitor for Aluminum in 1 M HCl.

Aluminum corrosion was inhibited by myrrh extract when it was placed in a solution of 1 M HCl. Several procedures were used for these tests, including weight loss WL, potential dynamic polarization PL, and electrochemical impedance EIS in addition to theoretical calculations like density functional theory (DFT), Fukui functions, and Monte Carlo simulation. Fourier transform infrared spectroscopy was used to analyze the compositional surface of Al. Scanning electron microscopy was used to determine the shape of the Al surface. The inhibition rate of Al corrosion in HCl with varying myrrh extract contents at 25-45 °C was studied. An analysis of the PL curves indicates that myrrh extract is an inhibitor of mixed type. Upon increasing the concentration of myrrh, the inhibition efficiency increased. Moreover, rising temperatures decrease inhibition efficiency. It was discovered that the inhibition process follows the Langmuir isotherm, demonstrating that a monolayer has formed on the surface of aluminum. Theoretical and practical studies proved the validity of the conclusions.

Surface morphology and corrosion behavior of pure aluminum and its alloys in aqueous sulfuric acid medium

AbstractAluminum and aluminum alloys are light materials with some of the preferences such as lightweight, high specific strength, good elasticity, and good workability that play an important role in today's modern and industrial world. The economic loss and environmental and safety problems are also the most concerning aspects of these materials. As a result, numerous studies are performed by the researchers to improve the overall environment throughout the materials world. That is why, in this study, the surface morphology and corrosion behavior of pure aluminum and its alloys, such as 7S10 and 7003H, were investigated in aqueous sulfuric acid medium through immersion process at different temperatures. Open‐circuit potential and potentiodynamic polarization techniques were used to evaluate the resistance to corrosion of pure aluminum and its alloys 7S10 and 7003H. The current density increased with increasing temperature in the case of the alloys, and pure aluminum showed the highest corrosion resistance properties. The surface roughness measurement was performed using atomic force microscope to find out the amount of roughness of the used materials before and after the immersion process. Surface roughness was higher on the alloys than in pure Al, which indicates that less corrosion was formed in pure Al than in the alloys. The surface morphology analysis was also carried out using scanning electron microscopic data. The results revealed that the alloy 7003H undergoes more corrosion than pure aluminum and 7S10 in sulfuric acid medium, which clearly indicates that pure aluminum has higher corrosion resistance than the alloys 7S10 and 7003H. The corrosion rate of the test materials decreased with increasing immersion time.

Systematic Study of Aluminum Corrosion in Ionic Liquid Electrolytes for Sodium-Ion Batteries: Impact of Temperature and Concentration.

The development of sodium-ion batteries utilizing sulfonylamide-based electrolytes is significantly encumbered by the corrosion of the Al current collector, resulting in capacity loss and poor cycling stability. While ionic liquid electrolytes have been reported to suppress Al corrosion, a recent study found that pitting corrosion occurs even when ionic liquids are employed. This study investigates the effects of temperature and Na salt concentration on the Al corrosion behavior in different sulfonylamide-based ionic liquid electrolytes for sodium-ion batteries. In the present work, cyclic voltammetry measurements and scanning electron microscopy showed that severe Al corrosion occurred in ionic liquids at high temperatures and low salt concentrations. X-ray photoelectron spectroscopy was employed to identify the different elemental components and verify the thickness of the passivation layer formed under varied salt concentrations and temperatures. The differences in the corrosion behaviors observed under the various conditions are ascribed to the ratio of free [FSA]- to Na+-coordinating [FSA]- in the electrolyte and the stability of the newly formed passivation layer. This work aims at augmenting the understanding of Al corrosion behavior in ionic liquid electrolytes to develop advanced batteries.

Experimental and theoretical assessments of the chamomile flower extract as a green corrosion inhibitor for aluminum in artificial seawater

The anticorrosive qualities of a number of natural items have been researched because of the growing concern regarding the environmental contamination produced by conventional corrosion inhibitors. Through electrochemical measurements, the current study evaluated the effectiveness of chamomile flower extract (CFE) in preventing the corrosion of aluminum in an artificial seawater solution. Atomic force microscopy (AFM) and scanning electronic microscopy (SEM) were used for surface examination. Utilizing FTIR, the chemical composition of CFE extract was investigated. Density functional theory (DFT) computations were used to conduct theoretical analyses of its main constituents. According to the electrochemical tests, corrosion inhibition increased as inhibitor concentration increased and reached a moderate inhibition efficiency of 75.66% at 20 mL/L. Polarization curves showed that CFE molecules behaved as mixed-type inhibitors and that their adsorption process primarily followed the Freundlich isotherm. Examination of the corroded aluminum surface by SEM and AFM confirmed the adsorption of compounds present in the extract. The main constituents of the natural extract's electronic characteristics were determined using chemical quantum calculations, which also clarified interactions between inhibitors and metal surfaces as well as adsorption modalities.

The role of acid–base interactions in the pitting corrosion of aluminum: a review

Abstract The review describes an electrode kinetic model of aluminum pitting nucleation taking into account the charge of the metal surface, the adsorption of chloride ions on the oxide surface, their penetration through the oxide film with the help of oxygen vacancies, and the dissolution of the underlying substrate with the initiation of pitting corrosion at the metal/oxide interface. It is shown that the critical pitting potential is a function of the potential of a thin layer of aluminum surface covered by oxide and the value of the pitting potential of a binary surface alloying is related to the isoelectric point of the alloying element oxide in the binary alloy. An electrode kinetic model of pitting initiation is described, which was used to explain the effect of surface alloying on the pitting initiation on binary alloys. A method for changing the surface charge by forming foreign surface organosilicon nanolayers bearing both negatively and positively charged groups was proposed. It has been established that four characteristics (q, Ψ 1-potential, E pit and the tendency of aluminum to depassivate) depend on the nature of ion-exchange groups, the degree of their acid dissociation, and the ion-chemical interaction with activator ions.

Corrosion of Aluminum and Aluminum Alloys Used for Rolling Stock

Corrosion of Aluminum and Aluminum Alloys Used for Rolling Stock

A comparative analysis on the effects of sodium nitrate and hexamine on the corrosion of aluminium alloy in an acidic environment

Despite aluminium and its alloys being relatively resistant to corrosion reaction as a result of their passivating tendencies, aluminium alloys usually succumb to acidic attacks resulting in mostly pitting corrosion. This study is focused on comparing the efficiency of sodium nitrate with that of hexamine on the acid corrosion of aluminium when used individually as inhibitors in 1 M Hydrochloric acid. The gravimetric method was used for the corrosion study. Sodium nitrate was found to have higher inhibitor efficiency of 94% compared to that of hexamine (44%), positioning the former as a better inhibitor for aluminium alloy in 1 M HCl. ΔGadso was evaluated and the obtained Standard free energy of adsorption were in the range of −13 to −17 kJ/mol for NaNO3 and −6 to −12 kJ/mol for hexamine, signifying the physisorption mode of adsorption.

The Corrosion of Aluminium by a Strawberry in a Lunch Box

The Corrosion of Aluminium by a Strawberry in a Lunch Box

Theoritical Studies of Corossion Inhibition of Coumarin and Coumarin Derivative on Iron by Density Functional Theory Approaches

Corrosion of iron is a persistent problem that affects its structural integrity and durability in various industrial applications. The design of effective corrosion inhibitors is crucial for mitigating aluminum corrosion. In recent years, coumarin derivatives have shown promising potential as corrosion inhibitors for iron due to their unique chemical properties. In this research, we employ density functional theory (DFT) calculations to investigate electrochemical parameters of coumarin derivatives on iron corrosion. Coumarin (a) and its derivative: hymechromone (b), esculetin (c), and scopoletin (d) are analyzed using DFT calculation. Some descriptor is used to identify such as ionisation energy (I), electron affinity (A), EHOMO, ELUMO, Egap, electronegativity ( ), hardness ( ), number of fraction electron transferred ( N). Based on the EHOMO, ELUMO, Egap, electronegativity ( ), hardness ( ), the order of inhibitor potential of coumarin and it derivative is c > d > b > a. However, based on the number of fractional electrons transferred ( N), the potential inhibitor of coumarin and it derivative are c > b > d > a.

Investigation of Multilayer Brazed Aluminium Corrosion Process by Electrochemical Noise

Investigation of Multilayer Brazed Aluminium Corrosion Process by Electrochemical Noise

Fluoride Ions Effect on the Corrosion Behavior of Pure Aluminum in Deaerated 0.05 M Sulfuric Acid Solutions

AbstractThe corrosion study of aluminum‐based materials is the topic of a great scientific attention because of increasing the applications in many sectors of these materials. The fluoride ions (F−) effect on the corrosion behavior of pure aluminum in deaerated 0.05 M sulfuric acid (H2SO4) solutions at 25 °C was investigated. The electrochemical measurements such as open circuit potential and potentiodynamic polarization were accomplished to study the effect of fluoride and sulfate ions present in the test solutions. The optical microscopic and atomic force microscopic images were taken to view the morphologies and surface roughness of pure aluminum which coincidence with the corrosion rates found from the immersion of the test specimens using weight loss method. The surface morphology and elemental compositions of pure aluminum was evaluated by scanning electron microscope and energy dispersive X‐ray spectroscopy, respectively. The results showed that the general corrosion was formed on the surface of pure aluminum. It is also revealed that the surface roughness and amount of corrosion of pure aluminum were increased by the presence of even a very small amount of fluoride ions in deaerated sulfuric acid solutions.

Silicone-Based Lubricant-Infused Slippery Coating Covalently Bound to Aluminum Substrates for Underwater Applications.

Wetting of solid surfaces is crucial for biological and industrial processes but is also associated with several harmful phenomena such as biofouling and corrosion that limit the effectiveness of various technologies in aquatic environments. Despite extensive research, these challenges remain critical today. Recently, we have developed a facile UV-grafting technique to covalently attach silicone-based coatings to solid substrates. In this study, the grafting process was evaluated as a function of UV exposure time on aluminum substrates. While short-time exposure to UV light results in the formation of lubricant-infused slippery surfaces (LISS), a flat, nonporous variant of slippery liquid-infused porous surfaces, longer exposure leads to the formation of semi-rigid cross-linked polydimethylsiloxane (PDMS) coatings, both covalently bound to the substrate. These coatings were exposed to aquatic media to evaluate their resistance to corrosion and biofouling. While the UV-grafted cross-linked PDMS coating effectively inhibits aluminum corrosion in aquatic environments and allows organisms to grow on the surface, the LISS coating demonstrates improved corrosion resistance but inhibits biofilm adhesion. The synergy between facile and low-cost fabrication, rapid binding kinetics, eco-friendliness, and nontoxicity of the applied materials to aquatic life combined with excellent wetting-repellent characteristics make this technology applicable for implementation in aquatic environments.

Investigating the potential of casein as a sustainable material in inhibiting the corrosion of aluminum in hydrochloric acid

AbstractIn this study, the efficiency of casein in inhibiting the corrosion of aluminum in 0.1 M HCl was evaluated. Based on the weight loss data, increasing the amount of casein in the electrolyte from 50 to 500 ppm at 298 K decreased the corrosion rate of aluminum, for instance, from 2.53 to 0.58 g m−2 h−1. It was also demonstrated that with casein, the activation energy of the corrosion phenomenon increased (e.g., from 6.52 kJ/mol without casein to 27.54 kJ/mol with 500 ppm casein). The electrochemical polarization studies illustrated that in the presence of 500 ppm casein, the corrosion current density remarkably decreased from 63.09 to 6.1 µA/cm2. This was compatible with the increase in the charge transfer resistance recorded by electrochemical impedance spectroscopy. Furthermore, the X‐ray photoelectron spectroscopy and atomic force microscopy techniques confirmed the adsorption of casein on the working electrodes, which caused an enhancement in the surface quality of the specimens.

Anticorrosive properties of aqueous Cichorium intybus seeds extract as a sustainable-green inhibitor for aluminum corrosion in hydrochloric acid solution: An experimental and DFT/MC/MD theoretical approach

The inhibitory effect of Cichorium intybus seeds (C. Intybus) on the corrosion behavior of Al 7075 alloy was evaluated in a 1 M HCl acid solution using chemical and electrochemical methods. The adsorption process was proved using FTIR, UV-Vis, Fluorescence, SEM, EDX, AFM, and contact angle measurements. The results reflect that C. Intybus provided excellent protection, and all measurements showed that the inhibition performance of extracts increased by increasing the concentration to reach 93.67% at 12% v/v. Furthermore, this substance functioned as a mixed-type inhibitor to obstruct the anodic and cathodic active sites on the surface of the metal. The study outcomes matched the monolayer Langmuir isotherm, and the calculated adsorption free energy and activation energy reflect that the inhibition mechanism featured the physisorption process. The computational studies were used to provide further confirmation of the adsorption mechanism and to find out how organic inhibitor molecules interact with metal surface using Density Functional Theory (DFT) with Lee/Yang/Parr (B3LYP) level, 6–311 + + G(d,p) as the basis function set calculation, Monte Carlo (MC), and Molecular Dynamic (MD) simulations. The findings showed good agreement with both the experimental and theoretical results. One of the important findings of this work is the possibility of using C. Intybus as a greener alternative and environmentally friendly resource for corrosion inhibition in an acidic medium.