The paper examines the process of obtaining silicon specimens diffusion-doped with manganese impurity atoms and possessing various crystallographic orientations. The objective of the study is to investigate the effect of diffusion doping with manganese impurity atoms on the physicochemical and tensile properties of silicon, as well as to produce silicon specimens with [111], [110], and [100] crystallographic orientations. The main technological regimes for the diffusion of manganese atoms in silicon at different temperatures and crystallographic orientations, which affect the distribution of manganese impurity atoms in the crystal lattice, have been determined. Experimental data have confirmed that the crystallographic orientation significantly influences the doping efficiency and the characteristics of the resulting materials. The results of this work may be useful for the development of new semiconductor materials in which electrophysical parameters strongly depend on the crystallographic orientation.
The article presents a technology for obtaining the base of a cutting tooth of the D6-22 type by the method of cross-wedge rolling (CWR), which ensures resource conservation and improved quality of the workpiece. A 3D model of the wedge tool, the results of structural studies, and a conclusion on the advantages of the proposed technology are developed.
The characteristics of local plasma-electrolytic treatment of a rotating shaft are examined. Changes are studied in the structural and phase composition of the surface layer, as well as in the tribological and corrosion properties in the contact zone of the electrolyte jet with the surface being treated and in adjacent areas of 45# medium-carbon steel. The formation of a gradient of structural and phase changes is demonstrated, which is determined by changes in temperature and diffusion intensity, as well as the cooling rate during quenching. The tribological effectiveness of local treatment is revealed, caused by the oxide layers acting as a lubricant in combination with a high-hardness matrix and increased load-bearing capacity of the surface profile after treatment. The presented treatment method reduces mass and volume wear by up to 32 times in the contact zone of the electrolyte jet with the surface. The polarization resistance in the sodium chloride medium after local treatment of the steel surface is found to increase, which is due to the influence of nitride and oxide phases.
The process of lithium dissolution (leaching) from the “black mass” obtained from spent lithium-ion batteries in aqueous solutions of sulfuric acid with the addition of hydrogen peroxide as a reducing agent was studied using the regression analysis method. The concentration of sulfuric acid, the concentration of hydrogen peroxide, and the duration of the leaching process at a solution temperature of 70°C were considered as input factors. Regression equations were obtained and the adequacy of the used mathematical model of the black mass leaching process was tested. The composition range of the lithium leaching solution was established in which the maximum extraction of lithium (54 mM) occurs at a solution temperature of 70°C in 100–120 min: 2.5–4.0 M H2SO4 and 2–3
A methodology for assessing the current density distribution at the edges of holes during electrolytic plasma polishing of AISI 316 stainless steel has been developed and tested. That methodology enables the quantitative evaluation of edge effects to optimize polishing modes for complex-shaped parts. The influence of the immersion depth (2 and 10 cm) and electrolyte temperature (40–100°C) on the material removal distribution and scattering capacity was studied. Different behavior was demonstrated for the upper and lower edges of the holes: the removal rate at the upper edge was, on average, higher. It was found that scattering capacity increased with increasing the immersion depth, and the most uniform finish was achieved at an electrolyte temperature of 80°C.
