International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The paper studies the evolution of microstructure and mechanical properties of copper wire during a new combined deformation process. The essence of the technological process is deformation of wire in a rotating equal-channel step matrix and subsequent drawing. The matrix rotates around the wire axis and thereby creates stress due to equal-channel angular drawing and twisting in the matrix. The deformed copper wire was investigated by transmission electron microscopy and EBSD analysis, as well as tensile tests and microhardness determination. The deformation resulted in an ultrafine-grained gradient microstructure having a high component of high-angle grain
boundaries. The tensile strength of the deformed copper wire compared to the undeformed one increases more than twice from 302 to 635 MPa, and the yield strength increases from 196 to 306 MPa, an increase of 56%. The use of such hardened copper wire in construction will reduce the weight of the structure by reducing the diameter.

One of the effective ways to control the properties of copper is to refine its structure to a nano- or ultrafine-grained level, and primarily with the help of severe plastic deformation. At the same time, radial-shear rolling is one of the promising methods for obtaining long-length rods with a gradient ultra-fine-grained structure. It is known from a number of scientific works that one of the main factors influencing the possibility of obtaining an ultrafine-grained structure in various ferrous and non-ferrous metals and alloys is the deformation temperature of these metals and alloys. The aim of the work is to study the influence of the deformation temperature at the radial-shear rolling mill on the microstructure evolution of copper. The following deformation temperatures of copper rods were selected for the planned studies: 20°C, 100°C and 200°C. The conducted studies have shown that the implementation of radial-shear rolling at ambient temperature compared with rolling at temperatures of 100°C and 200°C made it possible to achieve more intensive refinement of the initial structure. And first of all, this is due to the fact that with radial-shear rolling of copper, realized at ambient temperature, there are no dynamic return processes.

One of the effective ways to control the properties of copper is to refine its structure to a nano- or ultrafine-grained level, and primarily with the help of severe plastic deformation. At the same time, radial-shear rolling is one of the promising methods for obtaining long-length rods with a gradient ultra-fine-grained structure. It is known from a number of scientific works that one of the main factors influencing the possibility of obtaining an ultrafine-grained structure in various ferrous and non-ferrous metals and alloys is the deformation temperature of these metals and alloys. The aim of the work is to study the influence of the deformation temperature at the radial-shear rolling mill on the microstructure evolution of copper. The following deformation temperatures of copper rods were selected for the planned studies: 20°C, 100°C and 200°C. The conducted studies have shown that the implementation of radial-shear rolling at ambient temperature compared with rolling at temperatures of 100°C and 200°C made it possible to achieve more intensive refinement of the initial structure. And first of all, this is due to the fact that with radial-shear rolling of copper, realized at ambient temperature, there are no dynamic return processes.

The research of the technology of obtaining new copper-ferrochrome composite material has been done. The results of its structure and properties analysis are presented. The material structure consists of the copper base, non-dissolved coarse inclusions of ferrochrome, diffused zones, forming around these inclusions and phases, having formed in the place of completely dissolved inclusions of ferrochrome fine particles. The material has good mechanical properties and a high wear resistance due to the formed solid solutions of the carbides in the copper.

Experimental results for the quality of electron beam melting and refining of pyro-refined copper samples are analysed by an empirical model estimation approach. Investigation of the influence of the process parameters – melting power and time of refining on the removal efficiency of specific impurities, overall removal efficiency and material losses is performed.

The paper presents a review of the literature relative to the flue gas desulfurization methods for sulphuric acid (H2SO4) manufacturing. The covered topics include wet and dry methods. Particular attention has been paid to the desulfurization of the flue gas from the copper smelting industry that can lead to a generation of SOx rich streams resulting in high profitability of H2SO4 production.

In this publication we study the influence of the pressing force on the strength characteristics of sintered materials based on water – dispersed iron powders alloyed with copper. Three brands of iron powders were studied – AHC 100.29, ASC 100.29 and ABC 100.30, to which 2 and 4% electrolytic copper were added. After pressing with a force of 300 ÷ 800 MPa, they were sintered at a temperature of 1150 ° C for 1 h. Experiments were performed to determine three strength characteristics – tensile strength, yield strength, elongation. In determining the mechanical characteristics in order to prevent the influence of porosity, five measurements were made for each type of samples, and in the graphical interpretation of the results the arithmetic mean values were used.

Geopolymer based on iron-silicate fines (fayalite slag) were synthesized in alkaline and acidic media using activation solution
comprised of respectively alkali silicate and phosphoric acid solutions. The raw material consists of fayalite, magnetite and pyroxene which could be a conglomerate in some particles. The alkali activation occurs very slow at room temperature, while acid activation take place very rapid. The acid activated geopolymer binder phase include cracks probably formed by thermal gradient because of the rapid exothermal reaction. The morphology of the alkali activated geopolymers were presented by porous structure.

The work is devoted to the study of evolution of flaws in aluminium alloys of Al-Zn-Mg-Cu, Al-Cu-Mg-Мn alloying systems and to the determination of their connection with structural factors of the material such as the size and composition of intermetallic phases conditioned by heat treatment tempers, and also to the study of the effect of big number of physical factors on the long-term behaviour of structural elements of aluminium alloys, and to the determination of the rate of formation of corrosion damages in structural elements of the aircraft wing

Grain boundary wetting process takes place during the contact of solid metal phase with the metal melt. The liquid bismuth network formation along grain boundaries (GB) connected with wetting process was investigated in copper polycrystalline samples. The endothermic thermal effect in the temperature range close to complete GBs wetting transition temperature for Cu-Bi system was observed. Thermal effect size of GB wetting per mol of copper passed into bismuth melt during process of forming wetting GB channels was characterized as 21-23 kJ/mol.

Abstract: It was dedicated to solution of scientific and technical problem to increase the level of physical and mechanical and operational properties of the surface of steels by forming strengthened layers diffusion boriding and complex saturation boron and copper in a magnetic field.

Nowadays are very actual problems of working out waste of non-ferrous metallurgy such as converter slags of the copper enterprise. One of the new direction of additional extraction of copper from slags of converter section is combine method including mechanochemical activation and concentration by flotation of nanostructured initial material. The first stage – is receiving thin crumbled material with high degree of dispersion. This permit furnish an explanation of noticeable changing of properties of high dispersion materials: appearance of activity centers on the surface of minerals because there are alterations and become activity of electronics structures of surfaces layers as consequence of modification of surface. Moreover, take places processes of opening of capsules, including captured particles of some components (metals, minerals from slag, such as copper sulphides etc.). As far as, converting is going with high speeds it’s possible mechanical capturing of initial particles which didn’t participate in interaction during of process converting, minerals may be screened by slag melt. Under the condition of the slowly cooling predominated kinetic mechanism of geterogenic interaction in the silicacontainig system. On the basis of investigations was worked out the technological regulations and fulfilled the industrial probation.