Nonferrous Metallurgy
Trofimov E.A., Mikhailov G.G. Analysis of phase equilibriums in the Cu–S–O system at the temperatures of 1100- 1300 ° C
Using thermodynamic calculations, the oxygen and sulfur solubility surface in metal melt being in equilibrium with nonmetallic phases (the Cu–S–O system) was plotted. The surface plotted can be used for analysis of technological processes related to interaction of oxygen with sulfur in copper melt. The results of the calculations can be correlated with the other authors' data.
Vatulin I.I., Miklushevsky V.V. A study of sintered lithium carbonate and hydroxodialuminate products
Production of lithium metal using aluminothermic reduction of lithium aluminates requires development of effective method to synthesize five-lithium aluminate Li5AlO4, a compound being richer in lithium. Sintering of Li2CO3 lithium carbonate with Li2O · 2Al2O3× nH2O lithium hydroxodialuminate shall be considered as a more preferable method. Thermogravimetry, X-ray phase analysis, IR-spectroscopy and crystallography were used for investigation of the process. It is shown that practically 100 %-yield of Li5AlO4 in the form of low-temperature a -modification or high-temperature b -modification depending on the synthesis temperature may be produced in sintering a stoichiometric mixture of lithium carbonate and hydroxodialuminate for a comparatively short time period (~ 2 h).
Extractive Metallurgy of Less-Common and Precious Metals
Troshkin A.M., Melnikov Yu.T., Belova E.A. Kinetics of interaction of lead and copper with acid liquors over oxidizer
Kinetic regularities of copper dissolving in sulfuric and fluorosilicic acids as well as lead dissolving in fluorosilicic acid, over sodium nitrate in all cases, have been analyzed. Preference in application of sodium nitrate for providing for higher rates of the process is shown. The effect of hydrodynamic conditions on the kinetic of copper and lead dissolving was studied. The conditions of the process are established to be of diffusive type. Based on the temperature dependences of the metal dissolving rates the apparent activation energies (in kJ/mole) of the process were calculated: 11,1 (in the Cu–H2SO4–NaNO2 system), 15,3 (Cu–H2SiF6–NaNO2), and 20,3 (Pb–H2SiF6–NaNO2).
Drobot D.V., Chub A.V., Varganova A.A. Chlorination of powders of niobium, tantalum, titanium, and alloys on their basis
Processes of chlorinating individual niobium, tantalum, and alloys on their basis by chlorine have been investigated using an original plant that permits recording the interaction speeds. The main kinetic parameters of the processes were determined and the most probable vicissitude of the process was proposed. Effectiveness of the results obtained in designing the chlorination apparatuses was shown.
Casting Production
Gerasimov S.P., Neverov P.A. A sample for estimation of inclination of alloys to fracturing
A sample form and a casting mold to obtain it were designed. The mold enables to cast simultaneously a sample that has three different sections on which fractures are formed. An opportunity is forecasted to vary the sample cooling rate at the cost of heating and warming of the form with asbestos or chamotte. The sample showed high stability of the results with alloys of the Cu–Ni–Zn system (nickel silver). A dependence of MNTs-15-20 nickel silver hot brittleness on melt and mold warming temperatures, sample section thickness, chemical composition of alloy and content of impurities. It was found that hot brittleness index for the sample being proposed varies depending on 0,001 wt. % Bi, Sb, Mg, P, Pb.
Metal Forming
Shatalov R.L., Lukashkin N.D., Kokhan L.S. A procedure of critical stress estimation to provide for stability of nonferrous metal band rolling process
The effect of front and back tensions on tightening in band width and rolling stability has been investigated. The methods of determination and estimation of permissible values of tensions and contact friction coefficient providing for stability of rolling were developed.
Zagirov N.N., Biront V.S., Anikina V.I. Formation of structure of sintered material prepared from loose copper chips
A mechanism of interaction and sintering of copper loose chip particles in the process of hot compaction at T = 300¸ 450 ° C, p = 55¸ 150 MPa was considered. Using microstructure analysis, hydrostatic weighing and microhardness measurement, characteristics of structure formation and change of properties of pieces were established depending on the geometrical factors and the state of starting chip particles, preliminary heat treatment, and parameters of hot compaction process. The recommendations are given for manufacture of products with specified structural characteristics and required quality indices.
Physical Metallurgy and Heat Treatment
Nadezhkin M.P., Pevzner M.Z. On optimization of enlarged roll treatment process
The article considers features of distribution of chemical and phase compositions in width and thickness of a weld produced by argon-arc butt-seam welding of copper bands as well as single-phase and two-phase copper alloys with and without foreign additive. Zinc sublimation in the welding process was investigated. The weld structure and properties, in particular these of two-phase material, are determined to a great extent by variation of the chemical composition of the alloy within the ranges, which are regulated by the standard, and Zn sublimation rate. The technology including operations of pre-rolling and local heat treatment that raise weld strength and stability of the subsequent milling and rolling processes has been developed.
Belov N.A. Quantitative analysis of the Al–Fe–Mg–Si state diagram in the range of aluminum alloys of 6XXX series
A procedure of quantitative analysis of the Al–Fe–Mg–Si state diagram in the range of 6XXX series alloys in which practically all phases can be present and be in equilibrium with aluminum solid solution has been proposed. The given procedure is based on calculations of weight and volume fractions in four-phase ranges. Poly- and isothermal sections of the Al–Fe–Mg–Si state diagram as applied to AA6003 alloy are plotted in accordance with the procedure.
Powder Materials and Coatings
Popov V.A., Marmulev A.V., Kondratenkov M.Yu. A theoretical estimation of possibility to produce metal-matrix composites with small particles
The effect of particle size on phase nucleation of dissolved substance in melt on strengthening particles (SiC) has been theoretically investigated. The calculations made have shown that casting processes of producing composite materials with aluminum matrix and strengthening silicon carbide particles of small sizes result in chemical non-uniformity. It was found that it is expedient to use procedures without formation of liquid phase to produce metal-matrix composites on the basis of Al and SiC. The procedure being proposed allows us to estimate the calculations for other components of composite materials as well.
Kovshechnikov V.B., Litvinov N.I., Nakonechny G.V., Ovchinnikov R.V., Surov A.V. A study of erosion resistance of copper-iron and copper-nickel electrodes
Erosion of electrodes made of two-component material on the basis of copper with different content of iron and nickel is experimentally investigated. Erosion of the electrode material produced by alloy obtaining and powder processes has been determined. The experiments have been carried out in arc plasmatrons with capacity of no higher than 20 kW at industrial (50 Hz) and increased (5 kHz) frequencies.
Structural Macrokinetics. Self-Propagating High-Temperature Synthesis
Emelianov A.N., Shkiro V.M., Rogachev A.S., Kochetov N.A. Thermal conductivity of powder mixtures for gas-free combustion
Experimental data on thermal conductivity of powder titanium–carbon and nickel–aluminum mixtures in different gaseous media (vacuum, air, helium) are given. An important effect of the latter on thermal conductivity of heterogeneous mixtures studied that is related with improvement of heat exchange in the grain contacting zone in the presence of gas has been found.
Surface Engineering. Multifunctional Films. Corrosion and Metal Protection
Balandin Yu.A. Diffusion wear-resistant coatings on the basis of boron and chromium produced in fluidized bed
The processes of chromium-plating and boron-chromium-plating of iron, 08kp and Kh12M steels in fluidized bed have been investigated. Application of the latter allowed us to reduce greatly the time period of formation of diffusion layers during chemical-thermal treatment, and the complex saturation of surfaces of materials with chromium and boron allows us to improve their wear resistance and resistance to dissolution in zinc and aluminum melts.
Heat Engineering and Environment Protection in Metallurgy
Rutkovsky A.L., Saakyants A.A., Starikova T.V. Charge melting process modeling in rotary-kiln
A mathematical model of the process to use in calculations of material balances in the zinc production was developed as a result of investigation of charge mixture smelting in a rotary kiln by carrying out a multifactor experiment. The adverse effect of high contents of iron metal in charge mixture on the rotary-kiln processing was proved. The effect can be neutralized by introduction of granulated slag into the charge mixture.
Process Control and Automation
Eliseev E.I., Blinkova E.V., Shabarov K.N. A mathematical model of electrolysis of water zinc sulfate solutions
Using a QBASRUS language program, a mathematical model of the process of electrolytic zinc production from water sulfate solutions was developed. The program uses a minimum number of conditions according to which material, voltage and thermal balances are calculated. The program was used for optimization of the process by specific consumption of electric energy. Zinc electrolysis under the optimal conditions found can be accompanied by voltage: 3,683 V in the bath, current yield of zinc: 90,8 %, consumption of electric energy: 3330 kW · h/t.
Rutkovsky A.L., Saakyants A.A., Tekiev V.M., Bolotaeva I.I. Clarified-layer sediment quality control in thickeners by spectral technique
Spectral technique of clarified-layer sediment quality control in the thickener has been proposed. The technique is used in the device for measurement of clarified layer depth. For this purpose, an oscillation spectrum of a sampler in the intermediate layer that is formed in the boundary between clarified and non-clarified layers is additionally analyzed. Quality of sediment is determined from the values of transformed amplitude signals and oscillation frequency of the sampler.
Standards and Rules
Karetnikova N.V. A new view on standards
