Inorganic Materials (v.48, #15)

Determining low concentrations of Zr, Ce, La, and Y in heat-resistant nickel alloys by inductively coupled plasma atomic emission by N. B. Romanova; N. V. Pechishcheva; K. Yu. Shunyaev; V. I. Titov; N. V. Gundobin (1315-1319).
A technique for mass fraction determination of microalloying additions—Zr, Ce, La, and Y (from 0.001 to 0.1 wt %)—in heat-resistant nickel alloys by inductively coupled plasma atomic emission is described. Results from samples of nickel alloys are in good agreement with the data of spectrophotometric and chemical-spectral analysis. The values of thecontent of Zr, Ce, La, Y in artificial mixtures of nickel-based alloy are reproduced.
Keywords: heat-resistant alloys; microalloying control; ICP-AES method

Analytic possibilities of direct determination of impurities in pure nonferrous and rare metals (Ga, In, Cd, Al, Cu, Ni, and Sn) by the arc atomic emission method with application of multichannel atomic emission spectroscopy are studied. The conditions for the performance of the analysis are established. The limits of detection and determination of impurities in studied materials are estimated. The possibility to determine elements at a level of 10−4–10−5 wt % is demonstrated. The accuracy is checked by comparing the obtained results with values of the determined impurities proved by use of state standard reference samples or departmental standard specimens. Improved techniques of arc atomic emission analysis of high purity nonferrous and rare metals are developed. The techniques possess amended metrological characteristics and permit one to considerably reduce the time of carrying out the analysis.
Keywords: arc atomic emission analysis; MAES; nonferrous and rare metals; gallium; indium; cadmium; aluminum; copper; nickel; tin

An activating action of hexamethylenediamine is revealed in the copper (II)-catalyzed indicator reaction of iron (III) reduced by sodium thiosulfate. It is shown that the addition of hexamethylenediamine to a mobile phase (thin-layer chromatography) and the impregnation of paper with hexamethylenediamine (paper chromatography) enhance the efficiency of metal separation for the model mixture containing Cu (II), Hg (II), Cd (II), and Pb (II). The techniques for the sorption-catalytic determination of copper (II) with the help of Sorbfil plates, including those in combination with thin-layer chromatography, are developed; they work within the concentration range from 0.005 to 10 μg/mL, the detection limit being 4 ng/mL, which is approximately an order of magnitude lower than in solution. The methods are tested in analysis of waste and river waters.
Keywords: sorption-catalytic method; thin-layer chromatography; paper chromatography; hexamethylenediamine

Determination of fluorine in inorganic substances (Overview) by G. I. Bebeshko; Yu. A. Karpov (1335-1340).
This is a review of physical and chemical methods of determination of fluorine in inorganic substances which have been published in the last decade. Promising new indirect variants of molecular absorption spectrometry are presented, as well as widely applied methods of ion chromatography, potentiometry with fluoride selective electrode, and others.
Keywords: fluorine; physical and chemical methods of determination; inorganic substances

This is an overview of current methods of determination of chlorine in inorganic substances published in the last decade. Challenges of development of ICP-AES for determination of chlorine in aqueous media are demonstrated. Attention is paid to methods of determination not only of total chlorine and chloride ion, but to other forms of chlorine occurrence as well. Particular importance of determination of perchlorate ion is highlighted. Widely applied methods of ion chromatography, potentiometry, and spectrophotometry are presented in combination with flow analysis.
Keywords: chlorine; forms of chlorine occurrence; methods of determination; inorganic substances

Inductively coupled plasma atomic emission spectrometry (ICP-AES) and flame spectrometry are used to establish the stoichiometric composition of Li6Gd(BO3)3, Li5.4Na0.6Gd(BO3)3, LaB3O6, and SrB4O7 single crystals, including cerium-doped crystals. It is shown that flame spectrometry is more advantageous for analysis of pure borate crystals. ICP-AES is more universal and allows determining basic elements and admixtures independently of solvents used for decomposition of borate samples. Both methods provide sufficient accuracy of the analysis.
Keywords: single crystals; complex borates; stoichiometric composition; flame spectrometric analysis; ICP-AES

Study of the kinetics in crystallization of neodymium-iron-boron alloy containing zirconium additives by V. A. Glebov; A. V. Glebov; A. S. Bakulina; I. V. Shchetinin; Yu. D. Yagodkin (1355-1358).
The possibility of applying the Kolmogorov-Avrami equation to describe the kinetics of crystallization of Nd2Fe14B-based alloys is discussed; for the estimation of the fraction of the transformed volume, the results of magnetic measurements are used. A significant influence of zirconium additives on the kinetics of crystallization is revealed.
Keywords: permanent magnets; kinetics of crystallization; Kolmogorov-Avrami equation; neodymiumiron-boron alloys

Laboratory tribotests of thin carbon coatings in lubricants by A. N. Bol’shakov; I. A. Buyanovskii; Z. V. Ignatieva; V. A. Levchenko; V. N. Matveenko (1359-1363).
The basic means and methods for tribotests of modern thin coatings in lubricants are considered. The ball-on-disk, cylinder-on-plane, and ring-on-ring arrangement are used.
Keywords: tribotests; carbon diamond-like coatings; laboratory setups; antiwear and antifriction properties

The residual magnetization M R dependences of carbon steels on the quenching temperature T q are described using relations between the M R and the saturation magnetization of the steels, the relaxation magnetization, and coercive force. Many of the reference data on the maximum magnetic permeability μ m of carbon steels are shown to be unreliable. Data calculated from the dependence M R make it possible to estimate μ m of carbon steels quenched from various temperatures T q. It is shown that μ m possesses the highest sensitivity to changes in T q of carbon steels.
Keywords: carbon steel; quenching; nondestructive testing; residual magnetization; coercive force; maximum magnetic permeability

Investigation of deformation and fracture by acoustic emission data, correlation of digital images, and strain measurements by S. V. Panin; A. V. Byakov; P. S. Lyubutin; O. V. Bashkov; V. V. Grenke; I. V. Shakirov; S. A. Khizhnyak (1369-1378).
To analyze the deformation of solid bodies, it was proposed to use simultaneously three in situ methods of data registration, including loading diagram (macroscale level), correlation of digital images (mesoscale level), and acoustic emission (microscale level). The complex for multiscale in situ investigation of deformation and fracture processes, the operating principle of which is based on interconnection of duration of the characteristic stages of change in the informative parameters and their ratios with the leading scale level, was implemented. By the example of stretching of the samples of aluminum alloy D16 with cut of different depth, the characteristic stages of change in the derivative of the load applied, AE activity, and intensity of shear deformation on the degree of deformation were revealed. It was shown that the characteristic stages marked on graphs of changes in all informative parameters on time agree well between each other and refer to elastic deformation, parabolic strengthening, and crack propagation.
Keywords: acoustic emission; deformation; fracture; loading diagram; analysis of optical images; micromeso-macroscale levels of deformation

Features of the development of mixed type cracks in titanium alloy OT4 by V. N. Shlyannikov; S. Yu. Kislova; A. V. Tumanov (1379-1385).
The results of calculation and experimental study of the development of mixed type cracks in titanium alloy OT4 under uniaxial loading are presented. The values of T stresses and stress intensity factors are determined on the basis of the numerical analysis of the stress-deformed state of rectangular samples with a central inclined crack. The need to consider T stress in the constitutive relations of the stress-deformed state of the body with a crack is demonstrated as an example of trajectories of development of a curvilinear crack. The experimental data on the cyclic crack resistance of titanium alloy OT4 are interpreted with respect to the parameter of deformation energy density. The range of smaller values of the resistance of the material to the development of cracks in the mixed forms of destruction relative to the situation of normal fracture is established.
Keywords: mixed forms of destruction; density of deformation density; characteristics of cyclic crack resistance; titanium alloy