Papers by Keyword: X-Ray Fluorescence Analysis

Abstract: The objective of this study is to quantify the improvement of diffusion experiments in liquid alloys by using two measurement points of in situ X-ray fluorescence analysis (in situ XRF). The impurity diffusion coefficient of Bi in liquid Sn at 573 K was measured by monitoring the temporal change in the Bi concentration at two fixed points using in situ XRF. In the present study, two XRF measurement points were set in order to determine two unknown parameters that corresponded to the diffusion coefficient and the initial concentration at the measurement point just after complete melting. When only one measurement point is set for in situ XRF, the initial concentration is treated as a variable and the obtained impurity diffusion coefficients of Bi deviated by 20-30% from the reliable reference data. By using two measurement points for in situ XRF, the obtained impurity diffusion coefficient of Bi was (2.44±0.08)×10^-9 m²s^-1 and agreed with the reference data in the reported uncertainty of ±10%.

Abstract: The paper presents the results of analyzing the prospects of using clay raw materials in a composition with metallurgical slags for the production of ceramic products. The results of the analysis of the chemical and mineralogical properties of clay from the Khalilovsky deposit in the Orenburg region and nickel slags from the dumps of the South Ural Nickel Combine are presented. The studies were carried out using X-ray fluorescence and differential thermal analysis methods. The article presents the performed X-ray and derivatograms of slag and clay and the features of the experimental types of raw materials revealed during their analysis. The connection between the chemical and mineralogical compositions of the experimental clay and slags on the technological properties of finished ceramic products has been theoretically established. The use of XRF and DTA to study the characteristics of plastic and non-plastic raw materials made it possible at the first stages of the experiment to reject materials that were unsatisfactory in properties for the production of ceramic products, which contributes to the optimization of experiments, rational consumption of costs of newly mined clay raw materials.

Abstract: The article presents an X-ray fluorescence analysis of chalcogenide glassy semiconductors. The standard method is applied to determine the concentration of arsenic, selenium, and sulfur in alloys. This technique, the quantitative composition of the glasses is defined with an accuracy of ± 0.0002.

Abstract: Standardization is the activity of normalizing norms and rules which are in general obligatory for products, services and methods of measurement, control and testing. One of the main demands to the methods of analysis is to ensure a certain level of accuracy. Requirements for the analysis sequence and the accuracy of the measurement data are the result of a compromise between the consumer and the supplier of the analysis. It is suggested to use functional-target analysis in order to determine the relations between the properties and functions of the object. On the example of X-ray fluorescence analysis it is shown that it is possible to formulate the functions of the researched object and analyze the properties which are necessary to put these functions into practice. It allows for determining such indicators of the analytical method that can be assessed quantitatively. Such approach can be used to construct mathematical models to estimate the degree of accuracy required for solving specific problems of consumers of precise measurement information.

Abstract: In this paper the coatings on the titanium substrate surfaces obtained by the shaped-charge synthesis have been investigated. The shaped-charge synthesis was carried out using mixtures with specially synthesized complex salts containing W and Co. The studies included X-ray analysis, X-ray fluorescence analysis, and the measurements of coating microhardness. The relationship between mechanical properties of coatings and their phase and structural state has been determined.

Abstract: In this paper, influence coefficient of flux (αi,f) on X-ray intensity was proposed, by which the X-ray intensity of fusion beads with different dilution ratio can be corrected to the standard value. Hence, the unknown sample of random dilution ratio can be determined by the standard working curve after corrected withαi,f. It was found that αi,f obtained by the proposed experimental method can be applied in correction of fluorescence intensity in the routine analytical work with satisfactory results. There is no necessary of exact weighing for the sample and the flux with the correction of αi,f. Furthermore, the procedure of routine analytical work can be simplified greatly without getting the L.O.I ahead of weighing, by which the working efficiency can be improved as well.

Abstract: In the X-ray fluorescence analysis on sub-micron particle, application of the doubly curved crystal (DCC) spectrometer with Johansson-type geometry is effective to improve the lowest limit of detection because DCC makes it possible to focus and monochromatize an X-ray beam simultaneously. A strain-free crystal is essential for the high-performance focusing crystal spectrometer. We propose the application of the open-air type numerically controlled plasma chemical vaporization machining (NC-PCVM), which utilizes neutral reactive species generated by atmospheric pressure plasma, to fabricate the DCC substrate. By applying NC-PCVM technique, a curvature radius error of 0.08% was obtained, and there was no degradation of the crystallinity of the Si (111) substrate.