Aplication of dynamic impedance spectroscopy for construction of adsorption isotherms of molybdate ions on magnesium alloy

The effects of cerium implantation on the oxidation behavior of AZ31 magnesium alloys

Corrosion behaviors in physiological solution of cerium conversion coatings on AZ31 magnesium alloy

Microstructural, mechanical and corrosion characterization of (C-HA)SiCnws coating on AZ31 magnesium alloy surface

The rapid degradation characteristics of magnesium alloys limit its application in the field of orthopedic fracture fixation and cardiovascular stents. This study aimed to improve the corrosion resistance and biocompatibility of AZ31 magnesium alloys and prepare degradable implant materials. Micro-arc oxidation (MAO) was used to change the concentration of yttrium acetate in the electrolyte to prepare coatings with different yttrium content on the surface of AZ31 magnesium alloy. Through characterization, it is proved that the yttrium in the coating mainly exists in the form of Y3+. The polarization potential experiment shows that the micro-arc oxidation coating significantly improves the corrosion resistance of magnesium alloys. With the increase of yttrium acetate concentration in the electrolyte, the corrosion resistance of the coating first increases and then weakens. When the concentration is 0.0035mol/L, the coating has the highest corrosion resistance. The results of CCK-8 cytotoxicity experiment and cell morphology observation also proved that the cell viability in each group was greater than 140%, and the yttrium-doped coating on the surface of AZ31 magnesium alloy has no cytotoxicity, can promote cell growth, and has good biocompatibility.

A low wear resistance is a significant disadvantage of magnesium-based alloys widely used in industry. The results of plasma electrolytic oxidation (PEO) carried out in an aqueous-alkaline phosphate electrolyte with the addition of hexagonal boron nitride (h-BN) powder to obtain coatings with greater wear resistance on the surface of AZ31 magnesium alloy are presented. The PEO method is one of the most promising for surface treatment of magnesium alloys, since oxidation is carried out in alkaline aluminate, silicate or phosphate electrolytes with various functional additives. The addition of nanocrystalline hexagonal h-BN powder in the form of a suspension into the electrolyte volume does not affect the electrical parameters of PEO, and h-BN particles are incorporated into the structure of the formed composite coating, increasing the wear resistance. It is shown that the resulting coatings have a relief typical of PEO with developed morphology and porosity, which change depending on the oxidation time. In this case, the incorporation of h-BN particles into the coating occurs by an inert mechanism, since they do not undergo chemical transformations with the formation of new phases. Composite coatings obtained on the surface of the AZ31 magnesium alloy by the PEO method consist of crystalline phases of MgO and Mg3(PO4)2, regardless of the addition of h-BN particles to the electrolyte. The wear resistance of coatings is 6 – 8 times higher compared to the untreated alloy. The results obtained can be used to produce PEO coatings with increased wear resistance and use them in various sectors of the economy.

In-situ preparation of (Ti,Al) codoped blue PEO ceramic coating on magnesium alloy and chromogenic mechanism

An investigation of plasma electrolytic oxidation coatings on crevice surface of AZ31 magnesium alloy

Fabrication and characterization of a hydroxyapatite–methylcellulose composite coating on the surface of AZ31 magnesium alloy

The biodegradable ability of magnesium alloys is an attractive feature for tracheal stents since they can be absorbed by the body through gradual degradation after healing of the airway structure, which can reduce the risk of inflammation caused by long-term implantation and prevent the repetitive surgery for removal of existing stent. In this study, the effects of bicarbonate ion (HCO3−) and mucin in Gamble’s solution on the corrosion behavior of AZ31 magnesium alloy were investigated, using immersion and electrochemical tests to systematically identify the biodegradation kinetics of magnesium alloy under in vitro environment, mimicking the epithelial mucus surfaces in a trachea for development of biodegradable airway stents. Analysis of corrosion products after immersion test was performed using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). Electrochemical impedance spectroscopy (EIS) was used to identify the effects of bicarbonate ions and mucin on the corrosion behavior of AZ31 magnesium alloys with the temporal change of corrosion resistance. The results show that the increase of the bicarbonate ions in Gamble’s solution accelerates the dissolution of AZ31 magnesium alloy, while the addition of mucin retards the corrosion. The experimental data in this work is intended to be used as foundational knowledge to predict the corrosion behavior of AZ31 magnesium alloy in the airway environment while providing degradation information for future in vivo studies.

Effect of glycine addition on the in-vitro corrosion behavior of AZ31 magnesium alloy in Hank’s solution

Effect of D-fructose on the in-vitro corrosion behavior of AZ31 magnesium alloy in simulated body fluid

PurposeThe purpose of this paper is to study systematically the corrosion behavior of AZ31 magnesium (Mg) alloy with different concentrations of bovine serum albumin (BSA) (0, 0.5, 1.0, 1.5, 2.0 and 5.0 g/L).Design/methodology/approachElectrochemical impedance spectroscopy and potential dynamic polarization tests were performed to obtain corrosion parameters. Scanning electrochemical microscopy (SECM) was used to analyze the local electrochemical activity of the surface film. Atomic force microscope (AFM), Scanning electron microscope-Energy dispersive spectrometer and Fourier transform infrared spectroscopy were used to determine the surface morphology and chemical composition of the surface film.FindingsExperimental results showed the presence of BSA in a certain concentration range (0 to 2.0 g/L) has a greater inhibitory effect on the corrosion of AZ31, however, the presence of high-concentration BSA (5.0 g/L) would sharply reduce the corrosion resistance.Originality/valueWhen the concentration of BSA is less than 2.0 g/L, the corrosion resistance of AZ31 enhances with the concentration. The adsorption BSA layer will come into being a physical barrier to inhibit the corrosion process. However, high-concentration BSA (5.0 g/L) will chelate with dissolved metal ions (such as Mg and Ni) to form soluble complexes, which increases the roughness of the surface and accelerates the corrosion process.

Lithium-ion batteries (LIBs) are widely used in modern energy storage systems due to their high energy density and long cycle life. Electrochemical Impedance Spectroscopy (EIS) is a powerful non-destructive method for assessing battery performance and aging, and has traditionally relied on static EIS measurements performed under steady-state conditions. However, obtaining steady-state data is time-consuming and can interfere with battery operation. Dynamic electrochemical impedance spectroscopy (DEIS) addresses this issue to some extent, however, interpreting the transient nature of these data is challenging. In this study, we propose a new method to predict static EIS from DEIS using a long short-term memory neural network, thus saving measurement time. The results show that the complex mapping between dynamic and static EIS can be accurately predicted from static EIS by a deep learning approach with Mean Absolute Error of 0.0193 and 0.0080 for its real and imaginary parts, respectively. This study makes significant progress in simplifying the EIS acquisition, which makes battery diagnosis more efficient and flexible.

Construction of TiO ₂ /silane nanofilm on AZ31 magnesium alloy for controlled degradability and enhanced biocompatibility

Improving anti-corrosion properties AZ31 Mg alloy corrosion behavior in a simulated body fluid using plasma electrolytic oxidation coating containing hydroxyapatite nanoparticles