The Influence of Thickness of the Layers on Structural-Phase and Strained State of Multiperiod Nanolayer Ti/TiN Coatings

The influence of condition of vacuum-arc multi-layer TiN/Ti coatings on their phase composition, structure, stress state and mechanical properties has been studied. The regularities of the phase composition, structural state of stress, hardness with dependence on the magnitude of the negative bias applied to the substrate during the deposition and the thickness of the Ti and TiN layers in a multilayer coating were obtained. The analysis of the causes of observed changes, based on the mechanism of formation of surface layers of vacuum-arc coatings in the condition of implantation processes stimulated by applying a negative bias to the substrate was held. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3481

Tribological Characteristics of (TiZrHfVNbTa)N Coatings Applied Using the Vacuum Arc Deposition Method

The effect of the pressure of the nitrogen atmosphere during the formation of vacuum arc nitride coatings based on high entropy alloys of the Ti–Zr–Hf–V–Nb–Ta system on their structure, hardness, and tribotechnical characteristics is considered. It is shown that strong nitride forming components lead to the dependence of the structural state and properties on the pressure of the nitrogen atmosphere during coating deposition. Deposition at a nitrogen pressure of 0.4 Pa results in the formation of a texture with the [111] axis when the applied bias potential is –70 V and when the bias potential is equal to –150 V the textural structure is biaxial ([111] and [110]) textures and high value of hardness of 51 GPa Along with that the highest value of wear resistance (under oxidizing mechanical wear) is inherent to coatings formed under the pressure of nitro gen of 0.09 Pa. The strongest microdeformation of coating crystallites corresponds to this pressure

The use of plasma-based deposition with ion implantation technology to produce superhard molybdenum-based coatings in a mixed (C₂H₂+N₂) atmosphere

The influence of the pressure of a mixed gaseous atmosphere (80%C₂H₂+20%N₂) and the supply of a high-voltage negative potential in a pulsed form on the elemental and phase composition, structure and physico-mechanical characteristics of the vacuum-arc molybdenum-based coatings. It is shown that in the temperature deposition range 400…550 °С as a result of plasma-chemical reactions, the maximum nitrogen atoms content in the coating does not exceed 1.5 at.%. It is found, that at the maximum pressure of Р(C₂H₂+N₂)= 2.3∙10⁻¹ Pа when the γ-MoC phase is formed, an superhard state of 50.5 GPa (at a constant potential -200 V, without additional high-voltage pulse action) and 51.1 GPa (at a constant potential -200 V, with additional high-voltage pulse action) is reached.Для вакуумно-дугових покриттів на основі молібдену досліджено вплив тиску змішаної газової атмосфери (80%C₂H₂+20%N₂) і високовольтного негативного потенціалу (подається на підкладку в імпульсної формі) на елементний і фазовий склад, структуру і фізико-механічні характеристики формованого матеріалу. Показано, що в температурному інтервалі підкладки при осадженні 400…550 °С в результаті плазмохімічних реакцій максимальний вміст атомів азоту в покритті не перевищує 1,5 ат.%. Виявлено, що при найбільшому тиску Р(C₂H₂+N₂)= 2.3∙10⁻¹ Па, коли формується фаза γ-MoC, досягається надтверде стан 50,5 ГПа (при постійному потенціалі -200 В, без додаткового високовольтного імпульсного потенціалу) і 51,1 ГПа (при постійному потенціалі -200 В, з додатковим високовольтним імпульсним потенціалом).Для вакуумно-дуговых покрытий на основе молибдена изучено влияние давления смешанной газовой атмосферы (80%C₂H₂+20%N₂) и высоковольтного отрицательного потенциала (подаваемого на подложку в импульсной форме) на элементный и фазовый состав, структуру и физико-механические характеристики формируемого материала. Показано, что в температурном интервале подложки при осаждении 400…550 °С в результате плазмохимических реакций максимальное содержание атомов азота в покрытии не превышает 1,5 ат.%. Выявлено, что при наибольшем давлении Р(C₂H₂+N₂)= 2.3∙10⁻¹ Па, когда формируется фаза γ-MoC, достигается сверхтвердое состояние 50,5 ГПа (при постоянном потенциале -200 В, без дополнительного высоковольтного импульсного потенциала) и 51,1 ГПа (при постоянном потенциале -200 В, с дополнительным высоковольтным импульсным потенциалом)

Intercommunication of indexes of physical development and power preparedness of girls 18-20 years.

Connection is considered between the indexes of force of different muscular groups and anthropometric data of organism of girls. In an experiment 50 girls-students took part in age 18-20 years. Presented middle results of dynamometry of musles of fingers of hands, musles of back, and also middle indexes of physical development of girls. A cross-correlation analysis is conducted between the indexes of physical development and power preparedness. Studied and presented to the feature of intercommunication between the indexes of force of different muscular groups

Development of experimental alloxan model of diabetes mellitus

Background. One of the main causes that lead to the disability of diabetic patients is diabetic retinopathy (DR). The relevance of the problem of DR necessitates the development of optimal experimental models on experimental animals to find effective ways of correcting this pathology. The purpose of our work was to develop an experimental alloxan model of type 1 diabetes mellitus (DM) for the study of DR, which would not result in the lethal outcome of experimental animals under the action of alloxan; histological examination of changes in the tissues of the eyeball in the reproduction of the DM model for the selection of new effective methods for the metabolic treatment of DR in the early stages. Materials and methods. The experiment was carried out on white outbred Wistar rats weighing 180–200 g. The first group consisted of 20 animals that were not subjected to any influence, served as a control; second group — 30 animals, in which DM was modeled by administration of alloxan and fructose. Results. When modeling DR, vessel changes in the form of wall fibrosis, edema of the endothelium and vasospasm were found. There was also a decrease in the amount of pigment granules, dystrophic changes in the cells of the ganglionic layer and a layer of retinal rods and cones, which coincides with the descriptions of damage to the coats of the eyeball in patients with DM. Conclusions. In our studies, we have calculated the optimal dose of alloxan administration, which does not lead to the death of rats (the lethality of rats was absent) and is an effective model not only of DM in general, but also of DR

Facile Synthesis of β-Keto Sulfones Employing Fenton's Reagent in DMSO

A new facile method for the synthesis of β-keto sulfones employing xanthates, DMSO, and Fenton's reagent is described. The reaction proceeds under very mild conditions providing a cost-effective straightforward approach to various β-keto sulfones in high yields. © 2018 Georg Thieme Verlag. All rights reserved

Facile Synthesis of β-Keto Sulfones Employing Fenton's Reagent in DMSO

A new facile method for the synthesis of β-keto sulfones employing xanthates, DMSO, and Fenton's reagent is described. The reaction proceeds under very mild conditions providing a cost-effective straightforward approach to various β-keto sulfones in high yields. © 2018 Georg Thieme Verlag. All rights reserved