The main features of electrochemical deposition of coatings based on Ni–W binary alloy in the pulse current mode using pyrophosphate electrolytes were studied. Two electrolytes with a pH of 8.7 and 9.5 were used. The deposition was carried out with the current density varying in the range of 0.01–0.1 A·cm⁻², and the duty cycle (the relative pulse duration) was changed within the range 20–100%. The surface morphology and elemental and phase composition of the coatings were studied by scanning electron microscopy, energy-dispersive X-ray microanalysis and X-ray diffractometry. The experimental conditions allowing us to achieve the maximum Faradaic efficiency and W content in the coatings were determined. It was found that the pulse current mode enabled the fabrication of crack-free coatings with a thickness greater than 6 μm.

An analytical review of the modern state of the development of ion sources with solid electrolytes (superionic conductors) for the aerospace and ion-beam technologies is presented. The methods for...

One of the major lines of solar energy development is the creation of environmentally friendly, wasteless and cheap solar-grade silicon production technology. Currently the main silicon production technologies are based on reduction of silicon hydrogen chloride compounds: trichlorosilane, tetrachlorosilane, monosilane. These technologies use harmful and potentially dangerous compounds in quantity. These productions can be profitable only at big volumes (more than 1000 tons per year). The paper presents the research results of mathematical modeling and experimental research of metallurgical-grade silicon purification by the method of plasma chemical treatment of silicon melt up to solar-grade level with further direct crystallization in one reactor.