UDC 541.135.3:666.233
I. A. Novoselova, V. V. Malyshev, A. I. Gab, V. I. Shapoval (Kiev)
Electrochemical metallization of diamonds with molybdenum and tungsten carbides from ionic melts
To obtain galvanic coatings of molybdenum and tungsten carbides on diamonds by high-temperature electrochemical synthesis from salt melts, five electrolyte compositions were selected and studied: Na2WO4—MoO3; NaCl—Na2MoO4—Na2CO3; Na2WO4—WO3; Na2WO4—Li2WO4; NaCl—Na2WO4—Na2CO3. The components of the synthesis were an electrolytic refractory metal and the diamond itself, the surface of which becomes conductive under the experimental conditions. Optimal electrolysis conditions (temperature, cathode current density, duration) for depositing continuous high-quality coatings were determined. The performance properties of diamond powders with carbide coatings were assessed.
UDC 621.762; 666.3/7
N. F. Gadzyra, G. G. Gnesin, A. A. Mikhailik, A. A. Shulzhenko, A. A. Bochechka (Kiev)
New superhard ceramic material based on SiC—C
The results of synthesis and study of the structure of the powder of a solid solution of carbon in silicon carbide are summarized. Aspects of the formation of ceramics based on SiC—C under high pressure are considered. The role of carbon dissolved in the SiC lattice in the formation of a new superhard material is established.
UDC 658.012.122:621.921
P. I. Kravets (Kyiv)
Intelligent models and fuzzy algorithms and their application to optimize the synthesis of superhard materials. Message 1
A linguistic model of the synthesis process of superhard materials, a linguistic algorithm for correcting the control parameters of the synthesis process and algorithms for a clear assessment of the synthesis results, presented in the language of fuzzy sets and fuzzy logic, are considered, the results of modeling this model and algorithms are presented, recommendations for their configuration and use are proposed.
UDC 531.651:(546.26+666.233)
Yu. A. Klyuev, A. M. Naletov, N. A. Kolchemanov, B. N. Feigelson, N. G. Zudin (Moscow)
Some results of diamond color measurements
Based on the MKO-1931 system, a quantitative measurement technique has been developed that allows determining the color coordinates (X, Y), color saturation (S), the wavelength of the main color tone of diamonds lo and their integral transparency Te. The relationships between the S values and color gradations of the most commonly accepted color classifier systems for jewelry rough diamonds have been determined. The main differences between natural diamonds of the yellow (lo = 573 nm) and brown (lo = 580 nm) color series have been revealed. Based on the annealing data of synthetic diamonds, an analytical dependence of the influence of the concentration of C-centers on the color saturation of crystals has been established. It was found that with complete transformation of C-centers into
A-centers, synthetic diamonds retain residual color, the saturation of which is proportional to the concentration of A-centers or the total concentration of nitrogen in the crystal.
UDC 541.128.13:541.183.26
G. P. Bogatyreva, M. A. Marinich, V. L. Gvyazdovskaya, G. A. Bazaliy (Kyiv)
Surface Chemistry of Submicron Diamond and Cubonite Powders
Adsorption processes occurring on the surface of submicron diamond and cubonite powders in gaseous and liquid media were studied. Criteria for assessing adsorption activity were selected. It was found that the values of most adsorption-structural characteristics of diamond submicron powders are higher than those of cubonite powders. It is shown that the ratio of the hydrophilic-hydrophobic balance of the surface has a significant effect on the selective mechanism of adsorption. Heavy metal ions are predominantly adsorbed on the hydrophobic surface, and organic molecules – on the hydrophilic surface of diamonds and cubonite.
UDC 621.922.02-49.2:697.8.052
Yu. D. Filatov (Kiev)
Polishing of aluminosilicate materials with a tool with a bound polishing powder
A review of the results of studies of the regularities of the polishing process of silica- and alumina-containing materials is given. The mechanism of removal of the workpiece, formulated on the basis of the cluster model of wear, is described. The methods for calculating the parameters of the surface roughness of the part are analyzed. A technique for calculating the modulus of elasticity of the working layer of the polishing tool is described based on the requirements for the accuracy of the shape of the surfaces being processed. The ways of solving the problem of wear intensity of tool surfaces and the workpiece during the nonequilibrium polishing process of structurally heterogeneous non-metallic materials are determined.
UDC 621.919
S. F. Studenets, A. V. Chernyavsky (Kiev)
Analysis of experimental and theoretical dependencies for determining cutting forces during broaching of gray cast iron
A comparative analysis of a number of equations for calculating cutting forces during cutting broaching is given. Based on the results of the experimental and analytical study, the choice of the preferred dependence for determining the cutting force during cutting broaching of gray cast iron parts is substantiated.
UDC 621.762
T. M. Duda (Kiev)
Thermodynamics of surface phenomena ultradispersed diamond systems
The thermodynamics of surface phenomena of ultradispersed diamond systems is investigated. Calculated data on the true size of nanoparticles and free specific interfacial surface energy are obtained.
UDC 548.0
Yu. I. Sozin (Kyiv)
Diffractometry of coordination spheres is a new express method for studying the structure.