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This paper aims to investigate the fretting wear mechanism of an Al-Li alloy at room temperature, the tangential fretting wear tests were carried out.

The effects of displacement amplitude and fretting frequency on the tangential fretting wear characteristics were mainly investigated. The experimental data obtained are analyzed and compared.

The results indicated that the fretting friction coefficient increased with the increase of displacement amplitude. As the displacement amplitude increased, the wear scar morphology changed significantly, mainly in terms of delamination debris and furrow scratches. The wear mechanism changed from initial mild wear to more severe oxidative wear, adhesive wear and abrasive wear.

This paper extends the knowledge into mechanical tight connections. The conclusions can provide theoretical guidance for the fretting of mechanical tight connections in the field of automotive lightweight and aerospace.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2019-0490/

The purpose of this investigation was to synthesize a doped polyaniline‐containing coating and investigate the anti‐corrosion properties of the coating on Mg‐Li alloy.

The doped polyaniline pigments were prepared by two different methods using ammonium persulphate as oxidant and hydrochloric acid, phosphoric acid, p‐toluene sulfonic acid and sulfosalicylic acid as doping agents. The doped polyaniline was characterized by Fourier transform infrared (FT‐IR) analysis, X‐ray diffraction (XRD) and scanning electron microscopy (SEM). The coatings consisted of polyaniline, epoxy resin and other additives that were formed on Mg‐Li alloy. The anti‐corrosion properties of the polyaniline‐containing coating on the Mg‐Li alloy were investigated in 3.5 wt.% NaCl solution using open circuit potential logging and electrochemical impedance spectroscopy.

The results of the electrochemical tests indicated that the polyaniline‐containing coatings showed better anti‐corrosion properties, as compared to conventional epoxy coatings on Mg‐Li alloy when exposed in 3.5 wt.% NaCl solution. The coating containing 2 wt.% polyaniline (relative to the mass of epoxy resin) doped with hydrochloric acid had the best anti‐corrosion properties on the Mg‐Li alloy.

Previous reports on the anti‐corrosion properties of polyaniline‐containing coatings focused mainly on the surface of iron, steel, aluminum and magnesium, and there have been few studies on the anti‐corrosion properties as protective coatings for Mg‐Li alloy.

The purpose of this paper is to synthesise polyaniline‐SiO₂ (PANI‐SiO₂) composites and investigate the anticorrosion properties of polyaniline‐SiO₂‐containing coating on Mg‐Li alloy.

The PANI‐SiO₂ composites were prepared by in situ chemical oxidative polymerisation in phosphoric acid medium. The PANI‐SiO₂ composites were characterised by Fourier transform infrared, X‐ray diffraction and scanning electron microscopy techniques. The coating consisted of PANI‐SiO₂ composites and epoxy resin was formed on Mg‐Li alloy. The anticorrosion properties were investigated by open circuit potentials (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarisation curves.

The results indicated that the PANI‐SiO₂‐containing coating on Mg‐Li alloy demonstrated good anticorrosion properties in 3.0 wt% NaCl solution. It has been found that the OCP of PANI‐SiO₂‐containing coating were able to maintain more noble potential values in comparison to pure epoxy coatings in 3.0 wt% NaCl solution. EIS analysis indicated that the resistance of PANI‐SiO₂‐containing coating was more than 10⁶ Ω cm² in 3.0 wt% NaCl solution in immersion process. Furthermore, the corrosion current of PANI‐SiO₂‐containing coating on Mg‐Li alloy showed a significant reduction.

Previous reports on PANI‐SiO₂ composites were mostly focused on their conductivity and optical properties and there are few studies so far on their anticorrosion properties as protective coatings for Mg‐Li alloy.

This paper aims to investigate microstructure, corrosion behavior and mechanical properties of Mg-4Li and Mg-4Li-3Al.

The microstructure was characterized by using scanning electron microscopy and electron backscatter diffraction. The corrosion behaviors were measured by hydrogen evolution and potentiodynamic polarization tests. The mechanical properties were evaluated by tensile tests.

The addition of Al results in the precipitation of some Mg-Al phase and Al3Li phase particles, and the formation of some fine recrystallized grains.

Mg-4Li-3Al showed a higher corrosion rate than that of Mg-4Li, attributed to the precipitate particles in Mg-4Li-3Al causing microgalvanic corrosion and the change of grain orientation. The addition of 3 Wt. per cent Al increased the tensile strength by solid solution strengthening, precipitation strengthening, refinement strengthening and texture strengthening, whilst the elongation decreased by almost half.

The purpose of the present paper is to develop a new technology for producing magnesium alloy twin-rib aircraft brackets by the forging method.

An overall description of magnesium alloys is given, with particular emphasis placed on magnesium wrought alloys that are used in the aircraft industry. Methods for producing ribbed brackets are discussed and the location of these parts in aircraft structure is described. The forging process for producing AZ31 magnesium alloy twin-rib brackets was modelled numerically, and selected results of the simulations performed are presented. The simulation results were then verified under laboratory conditions using a three-slide forging press equipped with three movable working tools. It was assumed that the use of this machine would allow for obtaining twin-rib aircraft brackets with improved both functional and strength properties compared to the production methods used so far.

The results demonstrate that the method developed by the present authors permits the production of twin-rib brackets. Positive theoretical results and preliminary experimental results prove that it is justified that the research on magnesium alloys used in the aircraft industry be continued.

The production of twin-rib aircraft brackets from magnesium alloys by the technology developed by the present authors would lead to enhanced product quality with simultaneous reduction in production costs (reduced labour costs and material consumption as well as increased process efficiency). At present, magnesium alloy aircraft parts, mainly obtained from semi-finished products imported to Poland, are produced by casting and machining methods. They exhibit, however, much worse properties than elements produced by metal forming methods. In addition to that, the application of machining in the production of these part leads to higher production costs.

The originality of this study stems from the presentation of an innovative metal forming technology for producing twin-rib brackets. This method is unique on a global scale, and its basic assumptions have been granted patent protection. Also, the originality of the study stems from the fact that brackets are made from magnesium alloys, as these light metals are considered the future of structural materials used in the aircraft industry. Given the above, the research on developing the technology for producing parts made from these alloys using a three-slide press is justified.

This paper aims to report the influence of hexamethylenetetramine (HMTA) on phosphate coatings formed on AZ31 magnesium alloys.

These phosphate coatings were obtained by immersing magnesium alloys in phosphate baths with HMTA. The morphology and composition of the phosphate coatings were investigated via scanning electron microscopy, energy dispersive spectrometry and X-ray diffraction.

The phosphate coatings were mainly composed of CaHPO₄·2H₂O. The HMTA concentration in the phosphate bath influenced the crystallization and corrosion resistance of the phosphate coating.

The polarization curve shows that the anti-corrosion qualities of the phosphate coating were optimal when the HMTA concentration was 1.0 g/L in the phosphate bath. Electrochemical impedance spectroscopy (EIS) shows that the electrochemical impedances increased gradually when the HMTA concentration varied from 1.0 to 3.0 g/L.

Participants needed for task group on corrosion testing. We have been asked to draw our readers attention to the fact that participants are needed for ASTM Task Group G1.05.04 on Corrosion Testing at Elevated Temperatures and Pressures, a new activity of standards‐writing Committee GF‐1 on Corrosion of Metals.

This study aims to review the current one-step electrodeposition of superhydrophobic coatings on metal surfaces.

One-step electrodeposition is a versatile and simple technology to prepare superhydrophobic coatings on metal surfaces.

Preparing superhydrophobic coatings by one-step electrodeposition is an efficient method to protect metal surfaces.

Even though there are several technologies, one-step electrodeposition still plays a significant role in producing superhydrophobic coatings.

When smelting Al-Li alloy, the material inevitably comes into contact with various oxide-refractories. These refractories are subjected to varying degrees of melt-corrosion at high temperatures. The purpose of this study is to find stable oxide refractories at casting temperature.

Four materials were selected for evaluation, and their corrosion by the Al-Li alloy at casting temperature and different holding times was measured. Subsequently, scanning electron microscopy and energy-dispersive spectroscopy were used to study the interfaces. Stable refractory materials were selected by comparing the thicknesses of the reaction layers.

The thickness of the Al-Li/ZrO₂ reaction layer varies linearly with the square root of the holding duration. Therefore, the growth of the reaction layer is controlled by diffusion. The reaction layer of Al-Li/Al₂O₃ is thinner, and its growth is also controlled by diffusion. However, there were no obvious reaction layers between the Al-Li alloy and MgO or Y₂O₃. By comparing these reaction-layer thicknesses, the order of stability was found to be ZrO₂ < Al₂O₃ < MgO and Y₂O₃.

These results provide a scientific basis for the optimal selection of refractory materials for Al-Li alloy smelting.

The properties of materials under impact load are introduced in terms of metal, nonmetallic materials and composite materials. And the application of impact load research in biological fields is also mentioned. The current hot research topics and achievements in this field are summarized. In addition, some problems in theoretical modeling and testing of the mechanical properties of materials are discussed.

The situation of materials under impact load is of great significance to show the mechanical performance. The performance of various materials under impact load is different, and there are many research methods. It is affected by some kinds of factors, such as the temperature, the gap and the speed of load.

The research on mechanical properties of materials under impact load has the characteristics as fellow. It is difficult to build the theoretical model, verify by experiment and analyze the data accumulation.

This review provides a reference for further study of material properties.