Electro-spark alloying (ESA) method was used to create a coating on the surface of TC11 alloy (Ti–6.5Al–3.5Mo–1.5Zr-0.3Si wt%). The oxidation behavior of the TC11 alloy and its deposited coating was investigated in air at 700°C. The resulting structures were analyzed in great detail by metallographic analysis and by scanning electron microscopy (SEM)
Electrospark alloying by chromium-nickel steels X12CrNiTi18-9, X8Cr22Ni6Тi, X20CrNi72, X20Cr13, 12Ni14, heat-resistant alloy NiCr80-20 and pure metals Cr and Ni of steel 45 samples has been carried out. It is established that the resistance to oxidation of the formed doped layer in the temperature range 25 -1000°C depends on the combination of alloying elements of Ni and Cr, transferred from the anode material during electrospark alloying. The resistance of the samples to gas corrosion during a differential thermal analysis in the temperature range 25 -1000°C and a heat-resistant test for 7 hours at 730°C in a series of doped layers formed by Cr, Cr-Ni alloy, heat-resistant steels is analyzed and it is shown that the chrome coating exhibits the highest resistance to thermal action. It has been proved that the chemical composition of the doped layer rather than its macroparameters, namely continuity, porosity and thickness, has a primary importance for the ability of electrospark coatings to resist high temperature for a long period of time. The conditions for the formation of a heat-resistant protective layer on steel 45 are determined: a) the presence of unlimited solid solutions based on Cr, Ni, and Fe in the structure of the doped layer; b) ratio of the elements in the doped layer: Cr-15 wt% and Ni-40 wt%. The most balanced ratio of elements in the doped layer (Cr 15 wt% and Ni 40 wt%) is established that is capable of forming doped layer protective structures based on Cr 2 O 3 , NiO, NiCr 2 O 4 on the surface, to resist oxidation and to protect the substrate of structural steels. It is proposed to use as alloying material the NiCr80-20 alloy, which provides in the process of electrospark alloying a balanced ratio of Cr and Ni in the doped layer of steel 45 for the formation of heat-resistant protection.
The article considers the mathematical model of maintenance of samples of armaments and military equipment according to the state with parameter control, for which the distribution of time of trouble-free operation of weapons in the form of Weibul's law is used as a model of failures. Probable physical distributions have a certain advantage over simply probable distributions, because their parameters can be determined on the basis of both statistical characteristics of failures and analysis of failures of the physical process. In addition, diffusion distribution laws, such as diffusion-monotone and diffusion-nonmonotonic distributions, are now the most relevant. These facts have significant practical value, which determines the relevance of the research. Also, the article considers the dependences of the coefficient of technical use of the object on different characteristics of the service system and the object itself are determined. For the mathematical description of the processes inherent in the maintenance system, the apparatus of semi-Markov random processes in the classical representation is used. Weibul's distribution law is one of the least used due to its complexity. The main results of the work are obtained by numerical method. The dependences obtained as a result of the calculations show the existence of the optimal period of preventive maintenance of the object of control, in which the maximum value of its coefficient of technical use is achieved. The result of the work allows to establish the quantitative dependence of the coefficient of technical use on the reliability of control means, scale and form in the form of Weibul's distribution law in a wide range of periodicity of preventive maintenance.
У статті розглядаються основні питання методичного підходу до обґрунтування полігонного наряду бомбардувальної авіації при ураженні складних цілей. Метою дослідження є підвищення ефективності застосування бомбардувальної авіації при ураженні складних цілей за рахунок обґрунтованого полігонного наряду під час антитерористичної операції. Проведено обґрунтування методики визначення полігонного наряду бомбардувальної авіації при ураженні складних цілей.
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