scholarly journals Investigation of tungsten surface carbidization under plasma irradiation

2021 ◽  
Vol 2064 (1) ◽  
pp. 012053
Author(s):  
A Z Miniyazov ◽  
M K Skakov ◽  
T R Tulenbergenov ◽  
I A Sokolov ◽  
G K Zhanbolatova ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Phase Analysis ◽  
Experimental Work ◽  
Irradiation Time ◽  
Sample Surface ◽  
Optimal Parameters ◽  
Experimental Conditions ◽  
X Ray ◽  
Plasma Irradiation ◽  
Tungsten Surface

Abstract This paper presents the results of studying the formation of a carbide layer under various experimental conditions and the choice of the optimal parameters for carbidization of the tungsten surface under plasma irradiation in methane. Therefore, to assess the effect of the surface temperature of a tungsten sample during experimental work, the surface temperature of the sample was 1300-1700°C, and to assess the effect of the irradiation time, a range within 300-2400 s was selected. From the results of X-ray phase analysis of the surface of tungsten samples, concluded that the temperature of the sample surface and the duration of irradiation have a significant effect on the formation of a carbidized layer on the tungsten surface during plasma irradiation on plasma-beam installation.

scholarly journals INVESTIGATION OF TUNGSTEN SURFACE CARBIDIZATION UNDER PLASMA IRRADIATION

2022 ◽  
pp. 37-43
Author(s):  
G. K. Zhanbolatova ◽  
A. Z. Miniyazov ◽  
T. R. Tulenbergenov ◽  
I. A. Sokolov ◽  
O. S. Bukina
Keyword(s):  
Phase Composition ◽  
Surface Temperature ◽  
Test Temperature ◽  
Irradiation Time ◽  
Sample Surface ◽  
Literature Analysis ◽  
Optimal Parameters ◽  
Experimental Conditions ◽  
Plasma Irradiation ◽  
Tungsten Surface

This paper presents the results of a study of the formation of a carbidized layer under various experimental conditions and the choice of optimal parameters for carbidization of a tungsten surface under plasma irradiation. To study the effect of the surface temperature of a tungsten sample and the duration of plasma irradiation, experiments were carried out at a sample surface temperature of 1300 °C and 1700 °C with an irradiation duration of 300–2400 s. Analysis of the research results showed that the maximum formation of W2C on the surface is observed at a test temperature of 1700 °C. At a temperature of 1300 °C, the phase composition of the carbidized layer depends on the duration of plasma irradiation. According to the literature analysis, the formation of WC occurs on the surface of tungsten, from which C diffuses into the particle and forms the underlying layer of W2C. With an increase in the ion fluence, depending on the irradiation time and the temperature of the sample surface, the diffusion of C into W accelerates, the WC content decreases, and W2C becomes the dominant carbide compound.

Phase analysis of bulk samples using sample-tilting X-ray diffractometry

1992 ◽  
Vol 25 (5) ◽  
pp. 582-588 ◽  
Author(s):  
Q. Cong
Keyword(s):  
Phase Analysis ◽  
Diffraction Method ◽  
Sample Surface ◽  
Geometrical Optics ◽  
Crystal Plane ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
Depth Of Penetration ◽  
X Ray ◽  
Surface Reflection

In the Bragg–Brentano X-ray powder diffractometer, the sample-tilting X-ray diffraction (STD) technique probes a fixed depth of penetration from the sample surface. In this way, phase analysis can be carried out from the surface layers to the depth probed by the CBD (conventional Bragg–Brentano geometry X-ray diffraction) method. In the present paper, after derivation of the diffracted intensity and the observed crystal-plane azimuthal equations, attention is focused on investigations of the geometrical optics of X-ray surface reflection by comparing the STD and CBD methods. Some examples are given to illustrate the applications of the STD technique for solving phase analyses and related problems.

Accuracy in quantitative phase analysis of mixtures with large amorphous contents. The case of stoneware ceramics and bricks

2014 ◽  
Vol 47 (3) ◽  
pp. 835-846 ◽  
Author(s):  
Alessandro F. Gualtieri ◽  
Vincenzo Riva ◽  
Andrea Bresciani ◽  
Stefano Maretti ◽  
Marco Tamburini ◽  
...  
Keyword(s):  
Phase Analysis ◽  
Internal Standard ◽  
Quantitative Phase Analysis ◽  
Experimental Conditions ◽  
X Ray ◽  
Quantitative Phase ◽  
Factor Method ◽  
Counting Statistics ◽  
First Time ◽  
X Ray Absorption

For the first time, this work inspects the accuracy of quantitative phase analysis of both crystalline and amorphous components of stoneware tiles and bricks. A number of variables were considered: the nature of the internal standard, experimental conditions and counting statistics. The so-calledG-factor method has also been applied. The results of the X-ray powder diffraction analysis have been compared with the results obtained with optical microscopy and image analysis. Only the mixtures spiked with corundum and silicon yielded accurate weight estimates of the amorphous fraction, whereas the use of highly X-ray absorbing internal standards (such as fluorite, rutile and zincite) resulted in gross underestimations. In fact, microabsorption effects are found to drastically reduce the accuracy of the results when standards with linear X-ray absorption coefficients higher than 100 cm−1are employed. It was found that very low counting statistics reduced the calculated amorphous fractions in both bricks and stoneware tiles owing to partial masking of the major peak of the internal standard, namely corundum. The application of theG-factor method to the systems investigated was also evaluated. The results are poorer than those obtained using the internal standard.

scholarly journals Optimal Parameters for Obtaining Diammonium Phosphate from off-balance Phosphate Raw Materials of the Karatau Basin

2021 ◽  
Vol 71 (12) ◽  
pp. 85-96
Author(s):  
Guldana Shaimerdenova ◽  
Kurmanbek Zhantasov ◽  
Tynlybek Bazhirov ◽  
Almagul Kadirbayeva ◽  
Gulzat Jussupbekova ◽  
...  
Keyword(s):  
Production Process ◽  
Phase Analysis ◽  
Raw Materials ◽  
Diammonium Phosphate ◽  
Petrographic Analysis ◽  
Optimal Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Material Resources ◽  
The Republic

The article contains information about substandard material resources of phosphorite raw materials of the Republic of Kazakhstan. Samples of phosphate-siliceous raw materials of the Zhanatas Deposit were studied for the content of P2O5. To obtain diammonium phosphate (DAP), off-balance phosphorite from the Zhanatas Deposit was used, containing P2O5-16.18%. Technological solutions for the enrichment of substandard phosphate raw materials `Zhanatas` and the production of DAP from evaporated and non-evaporated WPA are proposed. Information on mineral petrographic analysis and the chemistry of the DAP production process based on the results of X-Ray Diffraction, X-Ray Phase Analysis, and SEM is provided.

Optimizing conditions for x-ray microchemical analysis in analytical electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 548-549 ◽  
Author(s):  
N. J. Zaluzec
Keyword(s):  
Solid Angle ◽  
Analytical Electron Microscopy ◽  
Incident Beam ◽  
Thin Foil ◽  
Experimental Conditions ◽  
X Ray ◽  
Microchemical Analysis ◽  
Analytical Electron ◽  
Image Position ◽  
Incident Beam Energy

The ultimate sensitivity of microchemical analysis using x-ray emission rests in selecting those experimental conditions which will maximize the measured peak-to-background (P/B) ratio. This paper presents the results of calculations aimed at determining the influence of incident beam energy, detector/specimen geometry and specimen composition on the P/B ratio for ideally thin samples (i.e., the effects of scattering and absorption are considered negligible). As such it is assumed that the complications resulting from system peaks, bremsstrahlung fluorescence, electron tails and specimen contamination have been eliminated and that one needs only to consider the physics of the generation/emission process.The number of characteristic x-ray photons (Ip) emitted from a thin foil of thickness dt into the solid angle dΩ is given by the well-known equation

The Basic Physical Principles of Ion, Electron, and X-Ray Detectors and Their Application to Microanalysis

1985 ◽  
Vol 43 ◽  
pp. 154-157
Author(s):  
A.J. Tousimis
Keyword(s):  
Ion Beam ◽  
Depth Resolution ◽  
Sample Surface ◽  
High Energy ◽  
X Rays ◽  
X Ray ◽  
Electrons And Ions ◽  
Spatial Depth ◽  
Minimum Surface Area ◽  
Physical Principles

An integral and of prime importance of any microtopography and microanalysis instrument system is its electron, x-ray and ion detector(s). The resolution and sensitivity of the electron microscope (TEM, SEM, STEM) and microanalyzers (SIMS and electron probe x-ray microanalyzers) are closely related to those of the sensing and recording devices incorporated with them.Table I lists characteristic sensitivities, minimum surface area and depth analyzed by various methods. Smaller ion, electron and x-ray beam diameters than those listed, are possible with currently available electromagnetic or electrostatic columns. Therefore, improvements in sensitivity and spatial/depth resolution of microanalysis will follow that of the detectors. In most of these methods, the sample surface is subjected to a stationary, line or raster scanning photon, electron or ion beam. The resultant radiation: photons (low energy) or high energy (x-rays), electrons and ions are detected and analyzed.

X-ray phase analysis in leucite systems

2007 ◽  
Vol 2007 (suppl_26) ◽  
pp. 531-536 ◽  
Author(s):  
J. Maixner ◽  
A. Kloužková ◽  
M. Mrázová ◽  
M. Kohoutková
Keyword(s):  
Phase Analysis ◽  
X Ray
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