Temperature dependence of TiN/TiAl3/Ti2AlN composite material electric resistivity

2019 ◽  
pp. 36-41
Author(s):  
A. A. Kondakov ◽  
A. V. Karpov ◽  
V. V. Grachev ◽  
A. E. Sytschev
Keyword(s):  
Composite Material ◽  
Electrical Resistance ◽  
Combustion Products ◽  
Specific Electrical Resistance ◽  
Constant Current ◽  
Gaseous Nitrogen ◽  
Full Agreement ◽  
X Ray ◽  
Temperature Range ◽  
Weight Content

The TiN/TiAl3/Ti2AlN composite material was obtained by filtration combustion of the porous TiAl intermetallic samples in gaseous nitrogen. X-ray phase analysis of combustion products provided data to calculate the weight content of each phase as follows: 42 wt.% TiN, 35 wt.% TiAl3, 20 wt.% Ti2AlN and 3 wt.% TiAl. The synthesized composite material containing Ti2AlN МАХ phase features good electrical conductivity of a metallic nature. Specific electrical resistance of the synthesized material was measured by a standard 4-point procedure at constant current in the temperature range 300–1300 K in vacuum 2·10–3 Pa. It was found that specific electrical resistance grows linearly from 0.35 to 1.25 μΩ·m as temperature rises. Subsequent measurements of this indicator at the following heating/cooling cycles demonstrated full agreement of obtained results. This fact indicates that the material has stable electrophysical properties in the investigated temperature range.

Studying changes in the electrical resistance of carbon-nanotubes-modified elastomers during their compression, stretching and torsion

2019 ◽  
pp. 128-138
Author(s):  
V. S. Yagubov ◽  
A. V. Shchegolkov ◽  
A. V. Shchegolkov ◽  
N. R. Memetov
Keyword(s):  
Composite Material ◽  
Smart Materials ◽  
Electrical Resistance ◽  
Materials Science ◽  
Measuring System ◽  
Constant Current ◽  
Matrix Composition ◽  
Space Industry ◽  
Different Types ◽  
Elastomer Composites

Developing "smart" materials with improved both structural and functional characteristics is one of the promising areas of materials science. Measuring the electrical resistance of CNTs-modified (various mass contents) polymers and in particular, elastomers during performing several tests (compression, stretching, and torsion) at a constant current is relevant in electrical engineering, mechanical engineering, aviation, and space industry. Changes in the elastomer shape under different types of testing lead to the destruction of macromolecules and the structuring of the material as a whole. Therefore, it is important to study the effect of CNTsbased modifying fillers on the elastomer. When compressing, stretching or twisting the nano-modified elastomer, along with the mutual movement of its macromolecular fragments and aggregates, the modifier particles also move, which generally determines the transport of electrons in the resulting structure and affects the physical and mechanical parameters of the composite material. To conduct studies, elastomers containing different amounts of a CNTs-based modifying filler were prepared. To investigate and elucidate relevant dependencies, a measuring system (MS) was constructed, which makes it possible to determine electrical resistance values of the composite material with different CNTs contents in the polymer matrix composition exposed to various mechanical loads. Basing the research results, it was established that the electrical resistance of the elastomer composites modified with 1.0–2.5 wt.% CNTs decreases when compressing from 0 to 100 N, whereas when the compression force ranges from 100 to 350 N, the electrical resistance remains unchanged. When the elastomer composites modified with 2–2.5 wt.% CNTs were stretched by 30–40 %, the electrical resistance was found to increase from 5·103 to 1.9·107 Ω.

Tem Structure Investigations of Low-Temperature MBE Grown Inalas Layers on INP Substrate

1992 ◽  
Vol 263 ◽  
Author(s):  
P. Werner ◽  
Z. Liliental-Weber ◽  
K.M. Yu ◽  
E.R. Weber ◽  
Z. Rek ◽  
...  
Keyword(s):  
Electrical Resistance ◽  
Stacking Faults ◽  
X Ray Diffraction ◽  
Real Crystal ◽  
X Ray ◽  
Group Iii ◽  
Temperature Range ◽  
Density Of Dislocations ◽  
Transmission Electron ◽  
Structure Investigations

ABSTRACTThe real crystal structure of In0.52A10.48As layers grown on InP<001> substrate as a function of the growth temperature (between 150°C and 450°C) was investigated. The following structural / electrical analyses were applied to the samples: transmission electron microscopy (TEM), x-ray diffraction and particle induced x-ray emission (PIXE). In the temperature range between 200°C and 450°C good epitaxial growth of InAlAs layers can be achieved with a low density of dislocations and stacking faults. Ordering of group-III elements on {111} planes was observed for these layers. Structure models of such ordered domains are discussed. At growth temperatures below 300 °C additional As (≈2%) is incorporated in the lattice. Growth at temperatures below 200°C leads to the formation of pyramidal defects with As grains in their cores. As-grown as well as annealed InAlAs layers show a nearly constant, high electrical resistance (106-107Ωcm) in the whole temperature range.

Reducing the Ecotoxicity of Pesticide Polluted Waters by Electrochemical Methods

2019 ◽  
Vol 70 (5) ◽  
pp. 1574-1578
Author(s):  
Cristian Neamtu ◽  
Bogdan Tutunaru ◽  
Adriana Samide ◽  
Alexandru Popescu
Keyword(s):  
Nitrogen Atmosphere ◽  
Constant Current ◽  
Polluted Water ◽  
Gaseous Nitrogen ◽  
Constant Current Density ◽  
Electrochemical Approach ◽  
Saline Waters ◽  
Thermal Combustion ◽  
Polluted Waters ◽  
Thermal Stability Of

Electrochlorination constitutes an electrochemical approach for the treatment of pesticide-containing wastewaters. This study evaluated the electrochemical and thermal stability of four pesticides and the efficiency of electrochlorination to remove and detoxify the simulated polluted water with: Acetamiprid, Emamectin, Imidacloprid and Propineb. This study reports the experimental results obtained by cyclic voltammetry and electrolysis at constant current density in association with UV-Vis spectrophotometry. In saline waters this pesticides are electrochemical active and anodic peaks are registered in the corresponding voltammograms. After thermal combustion, in a gaseous nitrogen atmosphere, a residue ranging from 15 to 45 % is observed at 500 �C.

Optical microscopic, X-ray diffraction, and electrical resistance studies of CuCl at high pressure

1979 ◽  
Vol 32 (4) ◽  
pp. 275-279 ◽  
Author(s):  
G.J. Piermarini ◽  
F.A. Mauer ◽  
S. Block ◽  
A. Jayaraman ◽  
T.H. Geballe ◽  
...  
Keyword(s):  
High Pressure ◽  
Electrical Resistance ◽  
X Ray Diffraction ◽  
X Ray

Fuel Formation and Conversion During In-Situ Combustion of Crude Oil

SPE Journal ◽  
2013 ◽  
Vol 18 (06) ◽  
pp. 1217-1228 ◽  
Author(s):  
Hascakir Berna ◽  
Cynthia M. Ross ◽  
Louis M. Castanier ◽  
Anthony R. Kovscek
Keyword(s):  
Oil Recovery ◽  
Photoelectron Spectroscopy ◽  
Combustion Front ◽  
Combustion Products ◽  
Combustion Tube ◽  
Cross Sectional ◽  
In Situ Combustion ◽  
X Ray ◽  
Study Results

Summary In-situ combustion (ISC) is a successful method with great potential for thermal enhanced oil recovery. Field applications of ISC are limited, however, because the process is complex and not well-understood. A significant open question for ISC is the formation of coke or "fuel" in correct quantities that is sufficiently reactive to sustain combustion. We study ISC from a laboratory perspective in 1 m long combustion tubes that allow the monitoring of the progress of the combustion front by use of X-ray computed tomography (CT) and temperature profiles. Two crude oils—12°API (986 kg/m3) and 9°API (1007 kg/m3)—are studied. Cross-sectional images of oil movement and banking in situ are obtained through the appropriate analysis of the spatially and temporally varying CT numbers. Combustion-tube runs are quenched before front breakthrough at the production end, thereby permitting a post-mortem analysis of combustion products and, in particular, the fuel (coke and coke-like residues) just downstream of the combustion front. Fuel is analyzed with both scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). XPS and SEM results are used to identify the shape, texture, and elemental composition of fuel in the X-ray CT images. The SEM and XPS results aid efforts to differentiate among combustion-tube results with significant and negligible amounts of clay minerals. Initial results indicate that clays increase the surface area of fuel deposits formed, and this aids combustion. In addition, comparisons are made of coke-like residues formed during experiments under an inert nitrogen atmosphere and from in-situ combustion. Study results contribute to an improved mechanistic understanding of ISC, fuel formation, and the role of mineral substrates in either aiding or impeding combustion. CT imaging permits inference of the width and movement of the fuel zone in situ.

Structural-phase transition in (Cu2Te)2−x(ZnTe)x at high temperature

2021 ◽  
pp. 2150113
Author(s):  
H. B. Gasimov ◽  
R. M. Rzayev
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
High Temperature ◽  
Single Crystals ◽  
Structural Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Xrd Study ◽  
Xrd Method

Cu2Te single crystal was grown by the Bridgman method. X-ray diffraction (XRD) study of Cu2Te single crystals in the temperature range of 293–893 K was performed and possible phase transitions in the mentioned range of temperature have been investigated. (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals also were grown with [Formula: see text], 0.05, 0.10 concentrations and structural properties of the obtained single crystals were investigated by the XRD method in the temperature range 293–893 K. Lattice parameters and possible phase transitions in the mention temperature range were determined for (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals for [Formula: see text], 0.05, 0.10 concentrations.

scholarly journals Chemical Stability of Ti3C2 MXene with Al in the Temperature Range 500–700 °C

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1979 ◽  
Author(s):  
Jing Zhang ◽  
Shibo Li ◽  
Shujun Hu ◽  
Yang Zhou
Keyword(s):  
Electron Microscopy ◽  
Chemical Stability ◽  
Metal Matrix ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Transmission Electron ◽  
Work First ◽  
Scanning Electron

Ti3C2Tx MXene, a new 2D nanosheet material, is expected to be an attractive reinforcement of metal matrix composites because its surfaces are terminated with Ti and/or functional groups of –OH, –O, and –F which improve its wettability with metals. Thus, new Ti3C2Tx/Al composites with strong interfaces and novel properties are desired. To prepare such composites, the chemical stability of Ti3C2Tx with Al at high temperatures should be investigated. This work first reports on the chemical stability of Ti3C2Tx MXene with Al in the temperature range 500–700 °C. Ti3C2Tx is thermally stable with Al at temperatures below 700 °C, but it reacts with Al to form Al3Ti and TiC at temperatures above 700 °C. The chemical stability and microstructure of the Ti3C2Tx/Al samples were investigated by differential scanning calorimeter, X-ray diffraction analysis, scanning electron microscopy, and transmission electron microscopy.

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