Mineral Processing
Piskunov A.N., Lepekhin V.M. On methods of qualitative simulation of manufacturing methods
The procedure of applying the qualitative simplified models of complex devices being represented as a group of standard processes as applied to the tasks to accomplish during concentration is considered. The models describe precipitation of particles in a stationary phase in an arbitrary force field. The device, in which a centrifugal separator providing for necessary capacity at prescribed extraction and an “ideal” magnetic fluid separator determining the concentrate quality, is an example of the above.
Extractive Metallurgy of Heavy Nonferrous Metals
Bychinsky V.A., Shadis V.S., Golovnykh N.V., Katkov O.M. Physical and chemical stimulation of the process to produce composite additives in the silicon metallurgy
One of the most interesting processes of structure–material transformation of silicon-bearing waste - solution of organomineral components on water solutions of alkali has been analyzed from viewpoint of the thermodynamics. Isoenthalpy self-heating of the system determining by two factors: alkalinity of the medium and amount of elemental silicon entering the interaction was found on the basis of simulation models of the interaction processes between NaOH water solutions and silicon-carbon-bearing composites of variable composition. A special attention was made to redox processes and gas phase formation in the system Si-C-O-H-Cl-e.
Extractive metallurgy of less-common metals
Strizhko V.S., Shekhirev D.V., Alimova R.E., Abryutin D.V. Study of purification of acid waste solutions by method of ion photoextraction using sodium diethyldithiocarbamat as a collecting agent
A method of ion photoextraction using sodium diethyldithiocarbamat (DEDTC) as a collecting agent was proposed for purification of acid waste solutions containing copper, zinc, and iron. The precipitation completeness of copper, zinc, and iron ions as DEDTC and hydroxides was studied in the range of pH 1,5 to 12,5. The experiments were carried out at stoichiometric ratio of collector–metal ion and 50 % excess of the collector. The residual metal concentration was determined by AAS method. Precipitation of copper, zinc, and iron was shown to take place in different degree in the acid range. Minimum values of pH were found when the complete extraction of metals took place.
Casting Production
Batyshev A.I., Batyshev K.A., Bezpalko V.I., Lyubavin A.S. On features of casting structure produced in partly heat insulated molds at crystallization under pressure
The effect of mechanical pressure and local directed cooling on the macrostructure and mechanical properties of cylindrical castings diam. 50 mm and height 100 mm made of commercial purity aluminium of A7 grade has been studied.
Porozova S.E., Makarov A.M., Kulmetieva V.B. Silumin structure and property change at filtration through foam ceramic filter
The effect of filtration through foam ceramic filter made of cordierite electroporcelain on microstructure and strength of cast silumin was studied. The dependence of filtrating efficiency on average diameter of filter cell and alloy pouring temperature was shown. Recommendations on choice of optimum filtration regime are suggested.
Metal Forming
Nesterov D.V., Romanenko V.P., Kharitonov E.A. Stimulation of the molding process of formed sections and tubular billets in rollers
Some fundamental principles used in simulation of a molding process of formed sections in rollers are analyzed and generalized. Taking the advantages and shortcomings of available simulation methods into account, a universal method of determination of shaping center geometry and deformations arising in the field space was suggested. The method can be used for automated design and further optimization of roll calibration and structure of shaping mills and tube-welding mills.
Moroz B.S. Mechanisms of temperature change during molding of aluminum alloys in the conditions of active friction action
Mechanisms of temperature rise during molding of continuous articles in conditions of active friction are found. The dependencies are suggested for calculation of article temperature at the outlet of the die in the run of the process.
Radyuk A.G., Titlyanov A.E., Mochalov N.A., Berent V.Ya. The effect of mechanical and heat treatments on properties of copper articles having aluminum gas-thermal coating
The effect of deposition regimes for aluminum gas-thermal coating, heat treatment and rolling on thickness and structure of diffusion layer, its wear resistance, roughness, and electrical conduction has been studied. A coating up to 420 m m thickness was deposited with arc sprayer ЭM-14M onto copper base (M1). Heat treatment was carried out in the range of 700-800 ° C, 2-4 h. It is found that the thickness of diffusion layer increases depending on the thickness of deposited coating, temperature, and treatment time, with the result that electrical conduction of the composite produced decreases. The diffusion layer is destroyed during rolling with appearance of cracks and filling them with more ductile copper and going it out to the surface, resulting to increase in electrical conduction. Surface wear resistance with fragments of diffusion layer exceeds some times the wear resistance of copper.
Physical Metallurgy and Heat Treatment
Volodin V.A., Kolachev B.A., Ryndenkov D.V., Dolgacheva K.V. On expediency of introducing the concept of strength equivalents of alloying elements in titanium alloys by aluminum and molybdenum
A term of strength equivalents of a -stabilizers and neutral strengtheners by aluminum and b -stabilizers by molybdenum is introduced. The equivalents are evaluated by the hardening action which alloying elements affect on ultimate tensile strength of commercial titanium alloys as compared to that of aluminum and molybdenum. Commercial and some prospecting pilot alloys produced in Russia, the USA, Great Britain, Germany, France, and China are compared in coordinates of “strengthening aluminum equivalent-strengthening molybdenum equivalent”. The zones corresponding to different strength levels are shown in this diagram.
Teryoshin N.V. Production of fibers of titanium nickelide by extraction out of the melt
Morphology, structure, and mechanical properties of rapidly cooled fibers of Ti-Ni alloy produced by extracting the melt out of a suspended drop have been studied. The characteristic temperatures of revealing the form memory effect were established.
Sisanbaev A.V., Astanin V.V., Kaibyshev O.A. Self-organization of cooperative deformation processes in aluminum tricrystalls
The effect of triple joints of grain boundaries on the development of grain boundary migration and grain-limited slide (GLS), the most important mechanism of hot plastic deformation, has been experimentally studied on model objects, aluminum bi- and tricrystals of different morphology. It is shown that availability of triple joint can not only retard, as is well known, but accelerate the GLS development. The acceleration is possible in the case of the GLS cooperation on adjacent boundaries, one of that is active. The cooperated GLS behaves as a self-organizing process, which is accompanied by changing the configuration of a triple joint towards facilitating the slide. The data obtained can be useful for understanding the processes of superplasticity and creep.
Powder Materials and Coatings
Kudryashov A.E., Levashov E.A., Andreev Yu.Ya., Sheveiko A.N., Sheveleva T.A. SHS-electrodes made of materials of M group (Ti, Ta, C, Mo) for electrospark alloying
The stucture and properties of new electrode materials of M group (Ti, Ta, C, Mo) produced by the self-propagating high-temperature synthesis (SHS) were investigated. The electrode mass transfer on stainless steel 12Х18Н10T was studied. The properties of electrospark alloying coating (thickness, denseness, microhardness, phase composition, wear resistance, corrosion resistance) were studied on stainless steel 12Х18Н10T and titanium alloy ВT-1.
Khramtsov V.D. Oxidation features of high-porous nichrome
The oxidizing features of high-porous cellulate nichrome produced by suspension-electrochemical method were studied at T = 800-950 ° C in the air. An equation binding the oxidation kinetics at high temperatures and structural characteristics of the material, average size of cellular pores and relative density, has been proposed. Changes in macro- and microstructures, strength in the process of oxidation were studied. It is found that scale resistance essentially reduces when decreasing the relative density from 12 to 3 % and average size of cells from 4,5 to 1,1 mm. It was shown that HPCM-nichrome can be used at high temperatures without significant loss of operational properties up to mass gain of 1,3-1,5 % (mass.) as a result of oxidation.
Grigoryan A.E., Rakhbari R.G., Rogachev A.S., Levashov E.A., Ponomarev V.I., Sheveiko A.N., Shtansky D.V., Ivanov A.N. Formation of structure and the properties of composite targets during gas-free combustion in the system Ti-Si-C. Structure and properties of magnetron Ti-Si-C-N-coatings
The paper represents experimental results on the structural formation of SHS products in the system Ti-Si-C. Phase formation and microstructure of products were investigated using the combustion front quenching method and X-ray techniques. It was shown that the sequence of phase formation in the combustion front depends on the type of initial reagent grains. Simultaneous formation of carbide and silicide grains makes it possible to obtain finely divided microstructure. Optimum concentration regions, where Ti3SiC2-based ceramics can be obtained, were found. Homogeneous and multi-layer composite targets for magnetron sputtering were produced by the SHS-compacting process. The structure, phase composition, and mechanical properties of such targets were studied. The paper gives the experimental data on the composition, structure, and properties of Ti-Si-C-N coatings produced by reactive bias magnetron sputtering of different SHS-targets.
Corrosion and metal protection
Andreeva Yu.Ya., Kutyrev A.E. Thermodynamic possibility of enrichment of surface layer of binary copper alloys by alloying component and vacancies
The thermodynamic tendency of Cu–alloys to enrichment of the surface by alloying metal (Ni, Mn, Al, Zn, Sn, In) of lower surface energy is analyzed. It is shown that excess Gibbs surface energy can be considered as a surface energy of vacancies in the surface layer (SL) of the alloy. On this basis a calculation of vacancy concentration in the SL is given as a function of the surface energy value and enrichment of the SL by alloying metal.
Chronicle
Ilyia Izrielovich Novikov
