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To decrease wear and friction, zinc dialkyldithiophosphate (ZDDP) has been used in engine oil for several decades, but the mechanism of the tribofilm formation is still unclear. The purpose of this study is to characterize the chemical details of the tribofilm by using high-resolution approaching.

An ISO VG 100 mineral oil mixed with ZDDP was used in sliding tests on cylindrical roller bearings. Tribofilm formation was observed after 2 h of the sliding test. X-ray photoelectron spectroscopy (XPS) and atom probe tomography (APT) were used for chemical analysis of the tribofilm.

The results show that the ZDDP tribofilm consists of the common ZDDP elements along with iron oxides. A considerable amount of zinc and a small amount of sulfur were observed. In particular, an oxide interlayer with sulfur enrichment was revealed by APT between the tribofilm and the steel substrate. The depth profile of the chemical composition was obtained, and a tribofilm of approximately 40 nm thickness was identified by XPS.

A sulfur enrichment at the interface is observed by APT, which is beneath an oxygen enrichment. The clear evidence of the S interlayer confirms the hard and soft acids and bases principle.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0035/

The self-assembled monolayers (SAMs) of inositol hexakisphosphoric (IP6) formed in NaCl solution at room temperature on the surface of Type 430 stainless steel (SS430) were studied. The paper aims to discuss these issues.

The corrosion inhibition behavior of the SAMs was examined by electrochemical polarization curves, and surface characterizations were studied by X-ray photoelectron spectroscopy.

The results showed that the IP6 molecules were adsorbed successfully on the SS430 surface and demonstrated the capability of corrosion inhibition. A maximum IE value of 71.81 percent was achieved due to co-adsorption of water. The SS430 electrodes exposed to media containing 5×10−3 mol/L of IP6 exhibited the best anti-corrosive performance.

The present paper will report for the first time the adsorption and corrosion inhibition performances of IP6 SAMs on the SS430.

Wool fabrics were treated with plasma under the influence of different plasma gases were assessed by Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy with Attenuated Total Internal Reflectance mode analysis (FTIR-ATR). Experimental results showed clearly that the surface feature and chemical compositions of LTP treated wool were varied much dependable on the nature of plasma gas used and the variations were finally discussed.

The purpose of this paper is to colour aluminium pigment to the highest chroma using SiO₂ and organic silane with dichlorotriazine reactive dye and investigate its reaction mechanism, chemical stability and thermal properties to improve its applicability in surface coatings.

Aluminium pigment was encapsulated by the catalysed sol-gel method using SiO₂, followed by modification with γ-glycidoxypropyltrimethoxysilane (GPTMS). Purified reactive dye (1-Amino-4-[3-(4,6-dichlorotriazin-2-ylamino)-4-sulfophenylamino]anthraquinone-2-sulfonic acid (X-BR)) was covalently immobilized onto modified SiO₂ to obtain coloured aluminium pigment. The reaction mechanism, chemical stability and thermophysical properties were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscope, transmission electron microscope and thermogravimetric analyses (TGA).

The results showed that X-BR was covalently attached to modified Al/SiO₂ with maximum colour grafting of 95 per cent when the dosage of GPTMS and X-BR per weight of modified Al/SiO₂ was 25 and 15 per cent, respectively, at pH 8.5 and a temperature of 40°C. The coloured aluminium pigment had good chemical stability with excellent anti-migration properties in many solvents.

The organic silane used required a careful control of pH to ensure maximum colour grafting efficiency meanwhile other silanes with amine groups could also be used effectively with different kinds of colorants besides reactive dyes.

The method used is less cumbersome and provides a simple route to preparing coloured aluminium pigment.

The use of organic-inorganic SiO₂/γ- GPTMS with purified reactive dye to covalently colour aluminium pigment to the highest chroma is novel and will help advance the frontiers of knowledge on coloration of aluminium pigments.

The paper developed a novel gallic acid-based rust conversion emulsion (RCE) that is applied in the treatment of rusted steels. The purpose of this paper is to investigate the methods for the synthesis of RCE and study the mechanism of rust conversion.

Conversion emulsion was prepared using styrene, acrylate and self-developed gallic acid (GA)-based rust converter (GRC) via seed emulsion polymerisation. The polymerisable GRC was synthesised by the ring-opening reaction of glycidyl methacrylate with natural GA. The effects of the GRC dosage and its feeding modes on the RCE synthesis were analysed. The corrosion resistance, surface morphology, composition and mechanism of rust conversion coatings were studied using electrochemical tests, scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS), respectively.

The results showed that conversion coating on rusted steels treated with RCE, with various dosages of GRC (weight per cent), synthesised using seed emulsion polymerisation, exhibited the best adhesion and corrosion resistance. Raman spectroscopy revealed that RCE converted the original multiphase rust into stable crystalline phases of α-Fe₂O₃ and Fe₃O₄. According to XPS and energy dispersive X-ray analysis, the phenolic hydroxyl groups of RCE were proposed to chelate with Fe ions to form macromolecular ferrum compounds.

The pre-rusted steels demonstrated a better corrosion resistance than rust-free steels after treatment with RCE.

The paper developed a novel GA-based RCE with high efficiency and environment-friendly method.

This work is expected to replace the conventional rust conversion paints and cause a significant impact on extending the service life of rusted steels.

The commercial stainless steels have been used extensively in the biomedicine application and their electrochemical behaviour in the simulated body fluid (SBF) are not uncovered obviously. In this research, the corrosion resistance of the commercial stainless steel of Fe–17Cr–xNi alloys (x = 4, 8, 10 and 14) has been studied. This study aims to evaluate the rate of corrosion and corrosion resistance of some Fe–Cr–Ni alloys in SBF at 37°C.

In this research, the corrosion resistance of the commercial stainless steel of Fe–17Cr–xNi alloys has been studied using open circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarization in the SBF at 37°C and pH 7.4 for a week. Also, the surface morphology of the four alloys was investigated using scanning electron microscopy, elemental composition was obtained via energy dispersive spectroscopy and the crystal lattice structure of Fe–17Cr–xNi alloys was obtained using X-ray diffraction technique. The chemical structure of the protective oxide film has been examined by X-ray photoelectron spectroscopy (XPS) and metals ions released into the solution have been detected after different immersion time using atomic absorption spectroscopy.

The results revealed that the increase of the Ni content leads to the formation of the stable protective film on the alloys such as the Fe–17Cr–10Ni and Fe–17Cr–14Ni alloys which possess solid solution properties. The Fe–17Cr–14Ni alloy displayed highest resistance of corrosion, notable resistance for localized corrosion and the low corrosion rate in SBF because of the formation of a homogenously protective oxide film on the surface. The XPS analysis showed that the elemental Fe, Cr and Ni react with the electrolyte medium and the passive film is mainly composed of Cr₂O₃ with some amounts of Fe(II) hydroxide at pH 7.4.

This work includes important investigation to use commercial stainless steel alloys for biomedical application.

This paper aims to investigate the corrosion behavior of zinc in a typical hot and dry atmosphere. It proposes the dynamic corrosion for different exposure periods. Results can provide the basic data and corrosion mechanism of zinc in such environment.

In this paper, the authors investigated the corrosion behavior of pure zinc exposed in the typical hot and dry environment in Turpan for one-four years, which has never been studied. Scanning electron microscopy, laser scanning confocal microscopy, electron probe micro-analyzer (EPMA), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were conducted to measure the corrosion morphology and products of zinc. Finally, combining electrochemical impedance spectroscopy and scanning Kelvin probe techniques, the corrosion mechanism of zinc in Turpan was examined.

The thickness loss of the zinc followed an exponential law with respect to exposure time: D = 3.17 t^0.61, and both of the rust layer resistance and the charge transfer resistance increased with exposure time. The corrosion products mainly comprised ZnO, Zn(OH)₂, Zn₅(CO₃)₂(OH)₆, Zn₄SO₄(OH)₆·5H₂O and Zn₁₂(SO₄)₃Cl₃(OH)₁₅·5H₂O. The Kelvin potentials shifted toward the positive direction from −0.380 to −0.262 V (vs saturated calomel electrode [SCE]) when the exposure time extended from one to four years and the distribution of the corrosion products became more and more uniform.

The corrosion behavior of pure zinc in the typical hot and dry environment in Turpan has not been studied. The dynamic corrosion for different exposure periods was obtained. The corrosion products were systemically investigated via energy-dispersive X-ray spectroscopy, EPMA, XPS and XRD.

To develop a new corrosion inhibitor formulation for carbon steel in low chloride environments.

Corrosion inhibition efficiencies were evaluated by the weight loss method and by impedance measurement studies. The nature of the inhibition process was evaluated using potentiostatic polarization studies. The nature of the protective film was investigated using X‐ray diffraction, X‐ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The concept of synergistic effect was used in the development of the new synergistic inhibitor formulation.

A new corrosion inhibitor formulation, containing tertiary butyl phosphonate (TBP), zinc ions and citrate, has been developed to control the corrosion of carbon steel in low chloride environments. This inhibitor formulation was found to offer a maximum inhibition efficiency of 96 per cent in a neutral pH test environment. It was interesting to observe that the binary system, consisting of higher concentrations of the TBP and zinc ions, offered only 79 per cent inhibition efficiency. The ternary system, consisting of relatively lower concentrations of the phosphonate, zinc ions and citrate offered a higher (96 per cent) efficiency. This ternary inhibitor system also was found to be efficient in acidic as well as basic environments in the pH range 5‐8. The inhibitor combination was determined to function as a “mixed”‐type inhibitor, though being predominantly cathodic. A plausible explanation of the mechanism of corrosion inhibition is proposed.

The ternary inhibitor formulations based on phosphonate, zinc ions and another environmentally friendly synergists like citrate will be quite useful for corrosion inhibition of carbon steel in cooling water systems as they contain relatively less concentrations of phosphonate and zinc ions.

The research paper presents the results of a new synergistic inhibitor formulation and also discusses the mechanistic aspects of corrosion inhibition.

The aim of this paper is to present results of investigations carried out on the front electrode of solar cells. Nowadays, most worldwide solar cell production is dominated by monocrystalline and polycrystalline silicon as a base material. In such cells, the electrical carriers are collected by the system of metallic paths fabricated on a silicon surface. One possible way to increase cell efficiency and reduce the production costs of solar modules is to replace the expensive silver by cheaper copper in front metallic electrodes.

The paper presents results of investigations performed on the front electrode of the solar cell. The investigations were focused on the modification of typical screen printing fabrication of the thin electrical finger paths of the front solar cell electrode. The resulting contacts were characterized morphologically (the dimensions and geometry of the front contacts) by scanning electron microscopy. The composition of finger path covered with copper was analyzed using energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy techniques.

In this work, the front electrodes were screen printed with the use of conventional silver-paste on a p-type Cz–Si-textured wafer with a n+ emitter and with an antireflection coating. After that, the fired front electrode was electroless coated with copper. The electroless copper deposition was performed in two stages. First, the surface of the photovoltaic cell was dipped in an aqueous solution of CuSO₄ and then dried in air at room temperature. When the surface dried, the cell was immersed in hydrogen fluoride solution (5 per cent) for 1 s followed by rinsing in deionization water.

The experiments confirmed the potential application of copper as an additional layer of the solar cell front metal electrode. On the one hand, this process is very simple and, on the other, the authors demonstrate a problem with the mechanical stability of the covered paths leading to electrode delamination.