In this study, TC4 (Ti-6Al-4V) titanium alloy was employed as the substrate, and micro-arc oxidation (MAO) coatings were fabricated in electrolytes containing different concentrations of Nd2O3 particles. The influence of Nd2O3 addition on coating growth behaviour, microstructural characteristics, and mechanical and corrosion performance was systematically investigated. Surface morphology, phase composition, hardness, and adhesion strength were analyzed, while corrosion resistance was evaluated in simulated seawater through electrochemical measurements. The results indicate that an Nd2O3 concentration of 1.5 g/L yields the most favorable coating formation conditions, characterized by enhanced growth efficiency and a compact microstructure. Under this condition, the coating exhibits a maximum hardness of 630.44 HV and an adhesion strength of 15.4 N. In addition, the corrosion current density decreases to 6.142 & times; 10-10 A cm-2 corrosion resistance has been significantly improved. These findings suggest that appropriate Nd2O3 incorporation during MAO effectively enhances the durability of TC4 titanium alloy in marine environments.
The influence was studied of argon consumption on the structure and properties of Ti-Nb-B-C coatings obtained by magnetron sputtering of a ceramic heterophase target of the composition (Ti,Nb)B2-40%(Ti,Nb)C. It was established that the optimum level of properties, including record-high hardness of 45 GPa and elastic recovery of 79%, as well as a minimum temperature coefficient of electrical resistance of -3 & times; 10-5 1/degrees & Scy;, achieved at a flow rate of 25 mL/min. The coating obtained at 75 mL/min demonstrated high oxidation resistance at temperatures up to and including 800 degrees C.
Particles of detonation nanodiamonds (DNDs) modified with a bifunctional silane—bis[3-(trimethoxysilyl)propyl]amine—were obtained. Successful completion of the modification was confirmed by IR spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. To obtain coatings with increased hydrophobicity, modified DND nanoparticles were introduced into a cycloaliphatic epoxy resin and into a hybrid binder based on an epoxy matrix modified with methylene diphenyl diisocyanate and polydimethylsiloxane rubber at different mass ratios. It has been shown that bis[3-(trimethoxysilyl)propyl]amine modified DNDs are a promising additive for producing hydrophobic coatings with high resistance to atmospheric corrosion.
The process of adsorption of Cu2+ ions by the native and modified pea pod husks is studied. The modification of the sorption material under study is executed with low-pressure high-frequency capacitively coupled plasma in an air atmosphere with the variation of the process parameters (power supplied to the electrodes of the plasmatron, time of plasma treatment). To determine the possible mechanism of interaction of the sorption materials with Cu2+ ions, the obtained isotherms are processed using the Langmuir, Freundlich, Dubinin–Radushkevich, Temkin, Flory–Huggins, Harkins–Jura, and Frenkel–Halsey–Hill adsorption models. It is found that plasma treatment results in an increase in the sorption characteristics of the sorption material under study due to the appearance of various oxygen-containing groups on the surface of the adsorbent. Regression equations and values of the approximation ratios R2 of the obtained isotherms are calculated by the above adsorption models. The thermodynamic parameters (Gibbs energy, energy of adsorption) are determined which evidence the occurrence of a process of physical adsorption at the initial stage. The calculated values of the Biot parameter indicate the occurrence of a mixed diffusion adsorption process. Subsequent occurrence of a chemical interaction between Cu2+ ions and functional groups in the composition of the biopolymers present in the composition of pea pod husks is shown by electron paramagnetic resonance.
