Modern Problems in Materials Processing, Manufacturing, Testing and Quality Assurance

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作者: Alexander I. Sechin, Olga B. Nazarenko, Yuliya Amelkovich
摘要: The feasibility of creating conditions for control of high-temperature synthesis (SHS) of nanomaterials has been studied. Experiments were carried out to determine the velocity of the combustion wave propagation of aluminum nanopowder obtained by electric explosion. In the course of the study, the factors influencing formation of the induction time: the thermal diffusivity of the substrate, the method of initiation of the combustion wave (flame, spark, heated body), the induction time between the initiating front and the front of the thermal explosion were considered. The relation describing the time of induction of thermal explosion is established.
作者: Dmitry Lipchansky, Olga B. Nazarenko
摘要: The thermooxidative degradation behavior of the epoxy composites filled with metal nanopowders has been investigated by thermogravimetric analysis under nonisothermal conditions in air atmosphere. The mechanical characteristics of epoxy composites were also studied by three-point bending method. The comparison of two different types of metal nanopowder was made. Aluminum and copper nanopowders prepared by electrical explosion of wires were used as fillers separately as well as in combination with conventional fame-retardant boric acid. It was shown that aluminum nanopowder increased slightly thermal stability of the epoxy composites. On the contrary, the introduction of copper nanopowder in epoxy resin led to rapid degradation of the epoxy composite. The combination of metal nanopowders and boric acid improved thermal stability of the epoxy composites. The highest flexural properties showed the epoxy composite filled with copper nanopowder.
作者: Yury Borodin, Tatyana Zadorozhnaya, Sergei Ghyngazov
摘要: The results on protonation in solutions and melts of salts and acids, as well as structural changes associated with the formation of nanocomposition structure of materials are presented. It is shown by structural methods that proton localization is invariant to the volume in the protonated layer and is accompanied by changes between oxygen distances, enlargement of the unit cell and transition to the rhombic phase. Having the maximum crystal-chemical activity, protons create a hexagonal lattice in accordance with the features of equipotential pictures of their nonequilibrium electrostatic fields. The increase in the integral intensity of reflexes observed on neutronograms of protonated LiNbO3 (102), (111), (113) it is associated with the ordering of protons in the hexagonal oxygen sublattice of the initial phase.
作者: Olga Galtseva, Sergey Bordunov, Alexandr Zhiganov, Inna Plotnikova, Jian Min Li
摘要: The paper shows fundamental possibility of processing of gold-bearing technogenic raw materials using the method of electric explosion. A series of experiments using a laboratory and pilot-production high-voltage pulsed discharge (HVPD) installation for the processes of enrichment of gold-bearing mineral raw materials of Komsomolsk mine tailings in Kemerovo region is conducted with a relatively low energy electrical discharge in the pulse of up to 112.5 Joules and the cost of electric power of about 1.5 kW/ton of raw material, that allows complete destruction of clay components agglomerations to less than 0.045 mm (micron and submicron sizes). Solid minerals such as quartz are simultaneously destroyed by defects in the grains and withdrawn from the installation with water, thus increasing gold degree of the concentrate. The results of particle-size and X-ray structural analyses of gold-bearing mineral raw materials of Komsomolsk mine tailings in Kemerovo region obtained by the method of electric explosion are discussed.
作者: Yulia Murashkina, Olga B. Nazarenko
摘要: Natural zeolite of Shivirtui deposit (Russia) was modified with nanofibers of aluminum oxyhydroxide AlOOH. Aluminum oxyhydroxide nanofibers were produced at the heating and oxidation of aluminum powder with water. The properties of modified zeolite were investigated by means of X-ray diffraction, transmission electronic microscopy, scanning electronic microscopy, low-temperature nitrogen adsorption, thermal analysis, and Fourier transform infrared spectroscopy. It was found that water content in the modified sample of zeolite was about 15 %. Based on the study of the physical and chemical properties, shivirtui zeolite modified with nanofibers of aluminum oxyhydroxide can be proposed for use as a flame-retardant additive to polymers.
作者: Anna Khaydarova, Mariya Matrunchik
摘要: The paper studies the surface structure and microhardness of the coating modified by the pulsed laser irradiation. The coating is obtained by plasma-jet hard-facing of the AISI (American Iron and Steel Institute) М2 high speed steel powder. The modes of the laser irradiation differ in peaking capacity, pulse duration and diameters of the focused laser beam. It is demonstrated that the weld penetration shape factor depends on the laser beam fluence and the pulse duration. In its turn, the weld penetration shape factor effects the quality of obtained irradiation zones.
作者: Anatoly Gormakov, Aleksey Golikov
摘要: The paper presents the experimental results of the possible use of the type 2024-T351 aluminum alloy for manufacturing the ball bearing rings of the rotary support system of the calibration equipment for magnetometric inclinometers. Non-magnetic materials for ball bearing manufacturing are reviewed. The description is given to the test equipment and procedures. The experimental results demonstrate that the type 2024-T351 aluminum alloy can be used for manufacturing a tailor-made ball bearing of the rotary support system. Stresses arising in the contact area do not exceed the allowable values of smax £ (0.3–0.5)s0,2.
作者: Fedor Simankin, Jan Miciński, Evgeniy Shumnyi, Alexander Shtein, Ablay Zhunusov
摘要: The paper presents the housing wall structure for the digital X-ray flat panel which can operate in extremely low temperature conditions. A technology of three-dimensional printing is proposed for making the detector housing with heat conductors incorporated in its wall structure.
作者: Alexander Gradoboev, Ksenia Orlova, Anastasiya V. Simonova
摘要: The most common technological solution for increasing the light efficiency of the LEDs based upon AlGaInP heterostructures are discussed in the paper. The creation of LEDs with the inclusion of quantum wells and quantum dots in the active region, removing the original base and placing the LED on a new substrate, the replacement of the absorbent substrate by the reflective, using light-reflective surfaces such as Bragg reflectors or a mirror base (substrate), the list of new based materials for the LEDs based upon AlGaInP heterostructures as same as sapphire, glass, gallium phosphide, silicon and silicon carbide are presented. Therefore, new advanced methods of emission power are emerging.