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The purpose of this paper is to obtain the environmental factor, which has the greatest effect on the corrosion rate of Q235 carbon steel under thin electrolyte layer, and to analyze the effect of this factor on the corrosion morphology, corrosion products and polarization process of Q235 carbon steel.

An electrochemical device, which can be used under thin electrolyte layer is designed to measure the corrosion current in different environments. Response surface methodology (RSM) is introduced to analyze the effect of environmental factors on corrosion rate. Scanning electron microscope (SEM) and X-ray diffraction (XRD) technique are used to analyze the results. The Tafel slopes of anode and cathode in different humidity and solution are calculated by least square method.

The three environmental factors are ranked according to importance, namely, humidity, temperature and chloride ion deposition rate. In a high humidity environment, the relative content of α-FeOOH in the corrosion product is high and the relative content of β-FeOOH is low. The higher the humidity, the lower the degree of anodic blockage, whereas the degree of cathodic blockage is independent of humidity. The above experiments confirm the effectiveness and efficiency of the device, indicating it can be used for the screening of corrosive environmental factors.

In this paper, an electrochemical device under thin film is designed, which can simulate atmospheric corrosion well. Subsequent SEM and XRD confirmed the reliability of the data measured by this device. The introduction of a scientific RSM can overcome the limitations of orthogonal experiments and more specifically and intuitively analyze the effects of environmental factors on corrosion rates.

The specific influence of calcium and sodium cations on the rate of deposition of a‐Fe2O3 (a main corrosion product in boilers and heat exchangers) has been experimentally studied. A deposition model based on the microlayer evaporation and dryout phenomena that occur in the nucleate boiling bubble is put forward for interpretation of the deposited layer. It has been found that the rate of deposition of Fe2O3 increases with the increase in valency of the soluble cations. With calcium, the deposition rate increases linearly with the increase in its ionic concentration, whereby the rate is increased by 5.9, 6.8 and 7.6 with 200, 400 and 600 ppm calcium respectively. Development of the deposition layer takes place in the valleys of the surface contour according to a micro‐layer evaporation mechanism. Successive deposition is performed at the periphery of the first deposit. Reduction in cation content in the crude solution and selecting smooth heated surfaces are recommended to reduce the ∝‐Fe2O3 deposition on heated surfaces in boiling water.

The purpose of this paper is to present a clear picture of the key factors of blind via and through hole filling in electroplating, e.g. shape of via or hole, electroplating solution, process, as well as the developments of mechanisms and models.

First, the paper details the development trends and challenges of via filling. Then the research status of mechanisms, electroplating solutions, including base solution and additives, numerical model and mass transfer is described. Finally, through hole filling is briefly reviewed.

To achieve excellent via filling performance, the characteristics of the via or hole, the ratio of acid/copper, selection of additives and factors of mass transfer are comprehensively considered in terms of optimization of the electroplating process. It is beneficial to design vias with appropriate aspect ratios, to strengthen the adsorption of the accelerator in the via bottom, to inhibit the increase of surface copper thickness and to form butterfly-shaped copper in the centre of through holes. Optimized process parameters should be taken into consideration in superfilling.

The paper reviews different sets of additives, mechanisms and superfilling models for state-of-the-art via filling and the developments of filling for through holes.

This paper aims to obtain rare earth magnesium alloy with good adhesion and corrosion resistance.

In 353 K oil bath, cyclic voltammetry was used to study the electrochemical behavior of Pr(III), Mg(II) and Ni(II) in choline chloride-urea ionic liquid. The constant potential method was adopted for electrodeposition of Pr-Mg-Ni ternary alloy films. The content of Pr in the Pr-Mg-Ni alloy films changes with respect to the deposition potential, deposition time and concentration ratio of Pr³⁺:Mg²⁺:Ni²⁺. Response surface methodology was applied to optimize the conditions for obtaining high-quality deposition films.

The results showed that the reaction of Ni(II) to Ni is irreversible; this result can be verified by Tafel polarization curve and chronocoulometry curve. Its transfer coefficient on the platinum electrode of 0.32 and diffusion coefficient is 1.0510⁻⁶ cm².s⁻¹. Mg(II) and Pr(III) cannot solely be reduced to their elemental form, but they can be induced via codeposition by Ni(II). The result shows that under a voltage of −1.00 V, the alloy coating with even structure is obtained when the concentration ratio of Pr³⁺:Mg²⁺:Ni²⁺ is 1:1:1 and the deposition time is 20 min. Scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy and other analyses revealed that the alloy coating is amorphous. Polarization curves of the cathode are tested, which manifest the lowest corrosion current density, stating which has good corrosion performance in alkaline solution and NaCl solution; this can be attributed to its dense film structure and good combination with the substrate.

It provides some technology for the production of corrosion-resistant materials.

The purpose of this paper is to investigate the effect of chloride along with NO₂ on the atmospheric corrosion of bronze using exposure tests.

Surface tension tests and electrochemical impedance measurements together with scanning electron microscopy (SEM) with energy dispersive atomic X‐ray, and X‐ray diffraction are used to characterize the corrosion behavior.

The results of the weight loss measurements show that the whole corrosion kinetics can be described approximately by: ΔW=atb; the synergistic effect of chloride and NO₂ is observed clearly, though no nitrate existed in the corrosion products.

A new catalyst theory has been suggested in this paper, i.e. that NO₂ acts as a catalyst during the corrosion process when significant quantities of chloride also are present.

It is now increasingly recognised that surface coating technology offers production engineers and designers significant opportunities to optimise the use of raw materials. Due to the forecasted shortage in a number of engineering metals, such as zinc, mercury, tin … etc., surface coating technology offers the most attractive finishing process, with material conservations. Suitable bulk materials may be selected for cost or structural reasons, whilst surface coating materials are chosen to meet specific surface properties, such as wear resistance, protection against corrosion, surface thermal and electrical conductance, optical reflections and decorative features. The recent design trends towards higher speeds, minimum airplane weight and maximum load capacity, however, encourage the use of light weight titanium fasteners in airplane aluminium alloy structures. This creates a serious galvanic corrosion problem to airplane skin sheets. In the following a new surface coating technique which is recently recognised as a growth of a new technology is applied to the problem of galvanic corrosion in air frame structures. The application of aluminium coatings for the protection of airplane skin sheets and fasteners against the galvanic corrosion in local environments is investigated. Both polarisation and galvanic tests are used for the evaluation of the potential of the new surface coatings. Furthermore both sodium chloride and sulphur dioxide electrolytes are used to simulate sea water and jet exhaust environments. Electrolyte saturation with either air or nitrogen are considered to compensate for the presence and lack of oxygen at different environments. It is concluded that the strong adhesion and the extensive graded interfaces of the ion plated films are responsible for the good protection of coated metallic couples.

Cyclic voltametric studies were carried out on mixtures of nickel sulphate, ferrous ammonium sulphate containing ethylene diamine tetra acetic acid, triammonium citrate, boric acid, Sodium chloride in the pH range of 8.5‐10.5 on platinum. The deposition of iron was found to involve the formation of FeOH⁺ and the second electron transfer is slow. The formation of iron nickel alloy film is anomalous. The charge transfer rates of FeOH⁺ and NiOH⁺ determine the deposition. Stripping voltametric curves revealed the dissolution of iron from an intermediate phase rich of iron in the iron‐nickel films.

The purpose of this paper is to establish a scientific understanding for electrochemical infiltration of laser sintered (LS) preforms.

Electrochemical deposition techniques were modified to induce infiltration of nickel ions inside porous LS structures with deposition on pore walls.

This novel process is feasible and has the potential to produce fully dense parts. Both conductive and non‐conductive preforms can be infiltrated by this method.

Removal of trapped fluids and gases inside the porous structure is one of the major challenges in the described electrochemical infiltration process.

This work enables low‐cost production of structural parts. It expands the application base for additive manufacturing, especially laser sintering technology.

The novel process carried out in this research is energy efficient when compared to state‐of‐the‐art vacuum‐melt infiltration.

The proposed process is a novel method for facilitating room‐temperature infiltration of porous LS preforms.

When concrete is manufactured, it can be instantaneously contaminated by chloride (Cl⁻) ions or later by their intrusion from the environment. This work aims to study the electrochemical behavior of the passive layer formed on the reinforcing steel surface in the presence of the same Cl⁻ ion concentration, with and without passivation time. This will, undoubtedly, affect the corrosion threshold values thereafter.

Electrochemical polarizations were carried out in two concrete pore solutions. The surfaces of samples immersed for 255 days in saturated Ca(OH)₂ solution were examined with optical and scanning electron microscopy and Raman microspectroscopy.

Cl⁻ ion origins in reinforced concrete lead to different values of corrosion thresholds. The passive layer behaves like a physicochemical barrier, and corrosion occurs at higher NaCl concentration thresholds. The formed passive film on the steel surface shows differences in the chemical composition and the morphology. The results show a rich presence of hematite. Maghemite, lepidocrocite, akaganeite and goethite are also present in much lower concentrations. The Cl⁻ ion presence in fresh concrete at the beginning of the manufacture harms the good formation and the good stability of these oxides, leading to corrosion initiation.

This study contributes to a better understanding of the passive layer role, not only in reducing the corrosion rate value but also in reconsidering new Cl⁻ ion corrosion threshold values.

The aim of this paper is to study the effect of the parametric sensitivity of all critical parameters of feed water and other operating variables on the corrosion rate and oxide scale deposition on economizer tubes of a typical coal-fired 250-MW boiler.

In this paper, a multilayer perceptron-based artificial neural network (ANN) model has been developed to envisage the corrosion rate and oxide scale deposition rate in economizer tubes of a coal-fired boiler. The neural network architecture has been optimized using an efficient gradient-based network optimization algorithm to minimize the training and testing errors rapidly during simulation runs.

The parametric sensitivity of all critical parameters of feed water and other operating variables on the corrosion rate and oxide scale deposition activities has been investigated. It has been observed that dissolved oxygen, dissolved copper content, residual hydrazine content and pH of the feed water have a relatively predominant influence on the corrosion rate, whereas dissolved iron content, silica content, pH and temperature of the feed water have a moderately major influence on oxide scale deposition phenomenon. There has been very good agreement between ANN model predictions and the measured values of corrosion rate and oxide scale deposition rate substantiated by the regression fit between these values.

This paper details the development of an alternative model to accurately predict corrosion rate and deposition rate on the inner surface of economizer tubes of a boiler over first principle-based kinetic model.