1,005 research outputs found

    Structural-Strained State and Mechanical Characteristics of Single-Phase Vacuum-Arc Coatings of Multicomponent High Entropy System Ti-V-Zr-Nb-Hf and Nitrides Based On It

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    In this work was shown the high stability of the single-phase structural state of high entropy alloy of Ti-V-Zr-Nb-Hf system in a vacuum-arc method of obtaining of coatings based on it. In the process of deposition single-phase high entropy coatings with bcc-lattice which characterizes the cast state are formed in vacuum, and upon obtaining in a nitrogen atmosphere single-phase nitride superhard coatings based on fcc-metal lattice are formed. Such a stability of structure of multi-element alloy to high temperature evaporation and deposition from high-energy plasma flows allows to use the techniques developed for simple substitution phases in the analysis of their structural-stress state. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3480

    Development of Formula Student Electric Car Battery Design Procedure

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    AbstractOne of the most important parts of a Formula Student Electric race car is a battery pack, which includes accumulators and a battery management system. Difficult operating conditions in a racecar require careful approach to battery pack design, from choosing accumulator cells to mathematical modeling. The developed design procedure allows choosing an optimal battery pack design based on given initial parameter

    Structural-Strained State and Mechanical Characteristics of Single-Phase Vacuum-Arc Coatings of Multicomponent High Entropy System Ti-V-Zr-Nb-Hf and Nitrides Based On It

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    In this work was shown the high stability of the single-phase structural state of high entropy alloy of Ti-V-Zr-Nb-Hf system in a vacuum-arc method of obtaining of coatings based on it. In the process of deposition single-phase high entropy coatings with bcc-lattice which characterizes the cast state are formed in vacuum, and upon obtaining in a nitrogen atmosphere single-phase nitride superhard coatings based on fcc-metal lattice are formed. Such a stability of structure of multi-element alloy to high temperature evaporation and deposition from high-energy plasma flows allows to use the techniques developed for simple substitution phases in the analysis of their structural-stress state. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3480

    On the statistical mechanics of an adiabatic ensemble

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    Different descriptions of an adiabatic process based on statistical thermodynamics and statistical mechanics are discussed. Equality of the so-called adiabatic and isolated susceptibilities and its generalization as well as adiabatic invariants are essentially used to describe adiabatic processes in the framework of quantum and classical statistical mechanics. It is shown that distribution function in adiabatic ensemble differs from a quasi-equilibrium canonical form provided the heat capacity of the system is not constant in adiabatic process.Обговорюються різноманітні підходи до опису адіабатичних процесів на основі термодинаміки та статистичної механіки. Для опису адіабатичних процесів в рамках класичної та квантової статистичної механіки використовуються рівняння для так званих адіабатичної та ізольованої сприйнятностей і їх узагальнення, а також адіабатичні інваріанти. Показано, що функція розподілу в адіабатичному ансамблі відрізняється від квазірівноважної канонічної форми при умові, що теплоємність системи при адіабатичному процесі є змінно

    Effect of Preparation Conditions in the Pressure Range of Atmospheric Nitrogen (2 ... 50) 10-4 Torr on the Structural and Phase State of the Vacuum-Arc Coatings of Mo-N

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    Nanocrystalline vacuum-arc nitride coatings possess the totality of unique structural states and properties (high hardness, wear resistance, oxidation stability, etc.). The coatings of the Mo-N system show a high hardness and low solubility of nonferromagnetic materials, thereby attracting great interest in their industrial use. Unfortunately, at present there is an apparent lack of information on the regularities of phase-structural state formation in the Mo-N system. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3535

    Structural-phase and Strained State of Vacuum-ARC Mo-N Coatings

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    The effect of substrate bias on the structural-phase and elastic stress-strained state during the formation of vacuum-arc deposited nanostructural coatings of the Mo–N system has been studied. An increase in the bias potential leads to (i) predominant [111] orientation of the growing molybdenum nitride crystals with a NaCl-type cubic lattice (γ-Mo2N phase) and (ii) the appearance of a second phase with a body-centered cubic crystal lattice that is characteristic of pure molybdenum. The elastically strained (stressed) state of the coating is determined not only by the conditions of deposition, but also by the mechanical properties of a substrate. In order to provide for formation of coatings in a high-elastic-strained (stressed) state, it is necessary to deposit coatings onto substrates with high elastic modulus, which prevent metal flow at the interface. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3480

    Basic principles of thermo-acoustic energy and temporal profile detection of microwave pulses

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    Basic principles of a thermo-acoustic method developed for the detection of powerful microwave pulses of nanosecond duration are discussed. A proposed method is based on the registration of acoustic pulse profile originated from the thermal expansion of the volume where microwave energy was absorbed. The amplitude of excited acoustic transient is proportional to absorbed microwave energy and its temporal profile resembles one of a microwave pulse when certain conditions are satisfied. The optimal regimes of microwave pulse energy detection and sensitivity of acoustic transient registration with piezo-transducer are discussed. It was demonstrated that profile of a microwave pulse could be detected with temporal resolution of 1 – 3 nanosecond
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