Structural and Energy State of Electro-Explosive Aluminum Nanopowder

2016 ◽  
Vol 712 ◽  
pp. 215-219 ◽  
Author(s):  
Andrei V. Mostovshchikov ◽  
Alexander P. Ilyin ◽  
Margarita A. Zakharova

Using XRD method it was revealed that in the stress-strain state of Al nanopowder lattice a non-significant amount of energy was stored (~0.385 J/g). Nevertheless, according to the data obtained by differential thermal analysis (DTA) the total amount of stored energy in the nanopowder was 348 J/g. The estimated value might be caused by the significant contribution of nanoparticles surface energy, which cannot be detected by means of XRD method. However, the method proposed in the paper can be applied to estimate changes in the structural and energy states of the lattice for nanoparticles or another micro-and nanopowders.

2013 ◽  
Vol 200 ◽  
pp. 50-53
Author(s):  
Inna A. Ivashchenko ◽  
Volodumur V. Halyan ◽  
Irina V. Danylyuk ◽  
Volodumur Z. Pankevuch ◽  
Georgij Y. Davydyuk ◽  
...  

The phase diagram of the Ga2Se3–In2Se3 system was investigated by differential-thermal analysis (DTA) and X-ray diffraction (XRD) method. The single crystals from the area of existence of the γ2 phase with the compositions (Ga0.6In0.4)2Se3 and (Ga0.594In0.396Er0.01)2Se3 were grown by a vertical Bridgman method. Absorption spectra of the grown crystals were studied. The estimated optical band gap is 1.95±0. 01 eV. The resistance of the single crystals of (Ga0.6In0.4)2Se3 (R=500 MΩ) and (Ga0.594In0.396Er0.01)2Se3 (R=210 MΩ) was measured.


Author(s):  
V. V. Kuzin ◽  
S. N. Grigor’ev ◽  
M. A. Volosova

С использованием базовых положений компьютерной инженерии изучено тепловое и напряженное состояние поверхностного слоя шлифованной Si3N4‒TiC-керамики четырех систем под действием теплового потока. Установлены закономерности распределения температур и напряжений в шести выделенных поверхностях поверхностного слоя. Определена специфика формирования структурной неоднородности напряжений и микроструктурных концентраторов напряжений, приводящих к изменению структуры керамики за счет образования несплошностей.


2021 ◽  
Vol 1 (7) ◽  
pp. 57-62
Author(s):  
V. V. Kuzin ◽  
M. A. Volosova ◽  
M. Yu. Fedorov

The regularities of influence of AlN and TiN coatings on stress-strain state of Al2O3‒TiC ceramics structural elements, which forming its surface layer, under influence of heat flow are established. The formation of microstructural stress concentrators at the boundary of AlN and TiN coatings with the initial ceramics is revealed.


2021 ◽  
Vol 53 (3) ◽  
pp. 301-310
Author(s):  
Srdjan Matijasevic ◽  
Vladimir Topalovic ◽  
Snezana Grujic ◽  
Veljko Savic ◽  
Jelena Nikolic ◽  
...  

The selected lithium germanium-phosphate glass was prepared by a conventional melt-quenching technique. The XRD method was employed to confirm the glass was obtained and to reveal crystalline phases during heat treatment. The dilatometry (DIL), differential thermal analysis (DTA), and differential scanning calorimetry (DSC) were used to determine the characteristic temperatures and enthalpies of crystallization and melting of the crystalline phase. The DTA and DIL were used to obtain the viscosity curves by applying the Vogel-Fulcher-Tammann (VFT) equation


Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.


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