Alloy electroplating using deep eutectic solvents (DES), compared to aqueous electrolytes, has essential benefits in a wide potential range, the high solubility of metal salts (including chlorides and oxides), and an environmentally friendly alternative. This research aimed to compare the coatings obtained by electrolysis of the Ni–Co alloy conventionally from an aqueous solution against the electroplating obtained in 2:1 ethylene glycol-choline chloride. The electrochemical behavior was studied through potentiodynamic polarization kinetic analysis carried out complying with Abner’s rules for alloy deposits; hydrodynamic conditions were modified, keeping the temperature at 60 °C and the salt concentration in both baths constant. As a result, nickel electrolysis has been carried out successfully by taking advantage of the benefits of using DES in energy consumption with 80% efficiency compared to water as a solvent under the same conditions. The composition and morphology of Ni–Co alloy coatings were characterized by scanning electron microscopy (SEM/EDS), and corrosion resistance was investigated by potentiodynamic polarization and electrochemical impedance (EIS). Coatings were obtained for both electrolytic baths with a chemical composition within the range of the alloy but with a higher cobalt content in the deposits obtained in water; in contrast, the distribution of the Ni–Co alloy was more homogeneous with changes in morphology and crystallization in the deposits obtained from the DES bath. The coatings’ anti-corrosion performance showed that the Co content difference increases the corrosion resistance of the Ni–Co alloy obtained from aqueous electrolytes compared to deposits obtained from DES.

Cast iron has stood for centuries of invention. It is a very versatile and durable material. Coating systems are a low-maintenance protection method. The purpose of this research is to increase the Paraloid coating’s resistance when applied to iron in high humidity atmospheres, with the addition of caffeine (1,3,7-dimethylxanthine) and nicotine (S)-3-(1-methylpyrrolidin-2-yl) pyridine as corrosion inhibitors; the resistance of protection versus exposure time will be evaluated by using electrochemical noise. A statistical analysis of the electrochemical noise signals was carried out. Recurrence plots were used as a powerful tool in the analysis to complement the data obtained and they predicted the evaluation of coatings behaviors performance versus time. The outcomes show that the addition of inhibitors increases and improves the performance as a temporary protection of Paraloid and that protection in high relative humidity was improved. Recurrence plots and parameter quantification show the variances in the surface corrosion dynamics.

In recent years, increasing interest has been placed in the development of Zn alloys for absorbable biomedical applications. It has been demonstrated that these alloys are potential candidates for endovascular applications. In the present work, a novel Zn-12.5Ag-1Mg alloy was investigated as a potential biomedical absorbable material. As a reference, the exhibited biocompatible properties are compared with those of pure Zn and a Zn-1Mg alloy. All the alloys investigated in this work were cast in a water-cooled Cu-mold (chill casting). Subsequently, the alloys were solution-treated and then extruded. The microstructural evolution at each stage of the alloy processing was resolved by analytical means including optical, scanning, transmission microscopy, and X-ray diffraction. By these means, the various phases belonging to this alloy system were disclosed. In addition, determinations of both corrosion and mechanical properties were carried out in the proposed Zn-12.5Ag-1Mg alloy. In particular, an excellent combination of strength and ductility was found, which is attributed to grain refinement as well as the precipitation of a uniform distribution of refined phases (i.e., AgZn solid solution, ε-AgZn₃, and Ag_0.15MgZn_1.85 intermetallics). All the precipitated intermetallics were embedded in a η-Zn matrix. As for the corrosion degradation in the physiological NaCl solution in the as-extruded condition, the experimental outcome indicates that the Zn-12.5Ag-1Mg alloy exhibits degradation rates far superior to currently reported ones for Zn-based alloys intended for absorbable biomedical applications.

Zinc coatings are commonly used to protect steel from different types of corrosion. However, zinc is an electrochemical reactive metal; applying surface treatment to galvanized materials is usually necessary to increase the system's lifetime. An alternative method for improving the service life of these coatings is the use of corrosion inhibitors. Nicotinic acid, chemically formulated as C₅H₄NCO, is a water-soluble vitamin. It is part of the B complex, which has been effectively tested in Zn and Zn-Al alloys in an acid medium, so it was proposed as a possible galvanized steel inhibitor as a pretreatment. Outstanding results determined a maximum efficiency in 20 ppm of nicotinic acid as a corrosion inhibitor for galvanized steel in NaCl 3%wt solution per 66.6% efficiency. In addition, nicotinic acid exhibits activity as a corrosion inhibitor to prevent the formation of pitting for galvanized steel in saline environments.

In this study, the effect of Ti content on the electrochemical behavior and passive film growth mechanism of Ni₅₀Nb_50−xTi_x (x = 10, 15, and 20 at.%) metallic glasses produced via melt spinning was investigated. Structural characterization via X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the fully glassy nature and chemical homogeneity of all alloys. Electrochemical performance was evaluated in a 3.5 wt.% NaCl solution using potentiodynamic and potentiostatic polarization, as well as electrochemical impedance spectroscopy (EIS). The results showed that increasing Ti content improves corrosion resistance by reducing corrosion and passive current densities and increasing charge-transfer resistance. The Ni₅₀Nb₃₀Ti₂₀ alloy exhibited the best electrochemical performance, associated with the formation of a more stable and protective passive film. The passive film growth mechanism was analyzed using the High-Field Model (HFM). A linear relationship between inverse capacitance and anodic potential confirmed that ionic transport through the oxide layer governs passive film growth. The calculated electric field strength decreased systematically with increasing Ti content, suggesting the formation of passive films with lower defect density and enhanced barrier properties. These results demonstrate that adding Ti significantly enhances the passivation behavior of Ni-Nb metallic glasses and promotes the formation of stable oxide films with improved corrosion resistance in chloride-containing environments.