A novel processing route, the combination of two-step tandem hot rolling (THR) and cold drawing, was recently developed to produce AA7050 wire products. The evolution of second phases, grain ...microstructures, and micropores during the whole process was thoroughly studied. The specific effect of second phases on continuous dynamic recrystallization (CDRX) and grain refinement was also systematically investigated, which was of great significance to optimize the processing parameters and further improve the mechanical properties of AA7050 wires. Firstly, both the strip-shaped microscale and tens-of-nanometer MgZn2 primary phases are observed in the as-received extruded sample. The strip-shaped primary MgZn2 phases break and gradually spheroidize throughout the THR process, with some of them redissolving into the Al matrix. However, the nanoscale MgZn2 phases are obviously coarsened and equiaxed only during the second-step THR process. After the first-step THR process, the coarse columnar grains are refined to thin fibrous grains due to the occurrence of CDRX, and a high number of dislocations are stored in the recrystallized structures. During the second-step THR process, only dynamic recovery occurs and no obvious CDRX is observable. This may be due to the coarsening of nanoscale MgZn2 phases, which reduces the driving force of recrystallization by attracting and combining with other solute atoms. The following two-step cold-drawing process has little influence on the primary MgZn2 phases, but promotes the formation of refined and equiaxed grains due to the recurrence of CDRX. This may be because the larger coarsened MgZn2 phases accelerate the recrystallization nucleation and increase the driving force of recrystallization.
MEFORM 2017Selected, peer reviewed papers from the 25th MEFORM Conference «New Developments in Wire Production and Processing», March 15-16, 2017, Freiberg, Germany.
The article proposes a methodology for determining and analyzing the determinant of the development of the industry, which makes it possible to formulate a list of applied recommendations for the ...formation of a strategy for the development of enterprises in the cable industry. The study uses a number of methods, the use of which allows us to explore the strategic prospects for the development of the industry, identify the determinants of development, evaluate them, and establish the nature of the impact on the activities of enterprises in the industry; highlight the structural and logical relationships between the studied factor conditions and development determinants, substantiate practical recommendations on the formation of a development strategy for enterprises in the industry. These methods include: methods of analyzing time series, methods of expert evaluation, the rhombus of state advantages by Porter, graph-analytical methods.The article provides statistical data on the volume of the world market for cable and wire products, identifies the main manufacturers and exporters of cable products. Trends in changes in the volume of production and sales of cable products in the world and in Ukraine are studied, in particular, the prospects for the development of the industry are substantiated. The main determinants of the development of the cable industry are determined, which are systematized and studied by the rhombus method of national advantages by M. Porter. Based on the method of expert assessment, a linguistic assessment of the established determinants is carried out, and the nature of their influence on the activities of enterprises in the industry is determined; the structural relationships between the studied factor conditions and development determinants are studied. The article provides arguments for choosing this particular methodological approach to analysis, which, on the one hand, makes it possible to ensure the complexity of the study - taking into account the systematic identification of determinants, the ability to take into account dynamic changes, determine the nature of their influence and track the structural and logical relationships between the studied factor conditions and development determinants. industries. Based on the results obtained, the author makes practical proposals for the formation of a strategy for the development of Ukrainian enterprises for the production of cable and wire products in the global and domestic markets.
To date, a "green" transformation of the industry is being carried out in the global energy sector, which will inevitably affect the decline in the level of consumption of natural energy resources, ...as well as the accompanying high financial and technological risks. The article discusses the issues of accelerating the possible energy transfer, in relation to enterprises producing cable and wire products. The analysis of possible methods and technologies that are aimed at making the transition and increasing the energy efficiency of cable machines is carried out. Improving the efficiency of technological processes will increase the profitability of the cable industry, as well as obtain significant savings in electrical energy. The solution of the task is focused on the use of an additional unit included in the electromechanical system of technological equipment having increased alternating loads (runout). The theoretical possibility of carrying out the improvement of cable machines has been studied by developing a mathematical model describing the physics of the process that ensures the energy efficiency of the proposed method. It is noted that the application of the considered method is possible not only for cable units and machines, but also for technological equipment with a certain shock load.
Ultrasonic vibrations contribute to drawing force reduction and surface finish improvement in the production of round wires. However, their effects on the drawing of irregular-shaped wires are rarely ...reported, as the process involves not only the shrinkage but also the reshaping of the cross-sections, which increases the difficulty in both numerical and experimental research. This work aims to investigate the influences of ultrasonic amplitude, drawing velocity, and area reduction ratio on the drawing force during the manufacturing of copper wires with rectangular, pentagon, and hexagon cross sections. The surface microtopography of the wire products was inspected using the Leica digital microscope and Hitachi scanning electron microscope (SEM). A remarkable drawing force reduction by up to 47% was observed when ultrasonic vibrations were added, especially for larger ultrasonic amplitude and lower drawing velocity occasions. The surface finish, however, was actually worse compared with under conventional drawing conditions, especially when ultrasonic amplitude exceeded 7 μm. This paper provides a potentially valuable method to enhance the efficiency of industrial production of irregular-shaped wires.
W.L. Gore and Associates, a Delaware materials company, has developed a new type of wire insulation that it says withstands chafing and electrically generated heat better than traditional wires, ...which could make the company's wire products especially suitable for the coming breed of high-voltage electric aircraft. Damage to wires can lead to electric arcing between separate wires. At minimum.this arcing could knock out electronics, or in rare worst-case scenarios, spark fires or even explosions on conventionally fueled aircraft. The insulation for Gore's new GWN3000 series aerospace wires creates a unique third category of wire, separate from the two traditional categories for aircraft, says Jim Carothers, product manager at Gore. Today, wires are coated with one of two kinds of composites: Either PTFE--short for polytetrafluoroethylene, also known as Teflon--and polyimide, or with XLETFE, which stands for cross-linked ethylene-tetrafluoroethylene.
The influence of room temperature flat rolling on microstructure, mechanical properties, and shape change in twinning-induced plasticity (TWIP) steel wire has been investigated to understand the ...deformation behaviors of flat rolled wire in TWIP steel and to apply TWIP steels to flat rolled wire products. Numerical simulation, hardness test, and EBSD techniques were used to analyze the distribution of strain, mechanical properties, and microstructure of flat rolled TWIP steel wire. The shape of flat rolled TWIP steel wire was also evaluated and compared with plain carbon steels having low strain hardening rate. A very different behavior of hardness, strain, twinning, and KAM value was observed with area of flat rolled wire due to the different stress state and strain with area of wire. The center area had the maximum twin density, KAM value, effective strain, and hardness; whereas free surface area had the minimum values. The hardness inhomogeneity factor (HIF) along the horizontal direction was much higher in comparison with that of the vertical direction. The maximum HIF value occurred at the specific reduction in height, i.e., 27%. This means HIF value gradually increased and then decreased with reduction in height, which is inconsistent with the results of plain carbon steel and Cu wire. The lateral spread and width of contact area of flat rolled TWIP steel wire were lower than those of plain carbon steels, indicating that material properties such as strain hardening exponent are crucial parameters that influence the shape of flat rolled wire products.
Graphic Abstract
Goal. The parameters of coated wire products are determined by momentum and heat transmission inside dies. As a consequence, it is essential to understand the polymerization movement, heat mass ...transmission, and wall stress concentration. The wire covering technique necessitates a boost in thermal efficiency. As a result, the goal of this study is to see how nanomaterials affect the heat and mass transfer mechanisms of third-grade liquid in wire coating analysis. The Buongiorno model is adopted for nanofluids. Methodology/approach. Continuity, momentum, energy, and nanoparticle volume fraction concentration is used to establish the governing equations. For highly nonlinear, the numerical methodology bvph2 technique is applied to yield numerical solutions. The impacts of the input parameters on motion, temperature, and volume fraction are examined using pictorial representations. Moreover, using the ND-solve, the numerical results are validated analytically. Findings. In Reynolds Modeling, the stress on the entire wire surface integrated shear forces at the surface dominate Vogel’s model, according to the analytical conclusions of this inquiry. It is observed that the nanomaterials appear to have a favorable impact on wire force throughout the entire surface and shear forces at the surface. The polymer velocity can be increased using a non-Newtonian parameter. The temperature profile is increased in the first half of the segment with larger values of random motion and nonlinear thermal while decreases in the later part. In addition, the Brownian motion component raises the concentration profile, but the thermophoresis factor decreases it. Practical implications. This research could aid in the advancement of wire coating technologies. Originality/value. For the first time, Brownian motion with generation/absorption slippage processes is used to investigate the importance of nanoparticles in wire coating assessment. Two different models are utilized for time-dependent viscosity: Reynolds and Vogel models.
The convective heat and mass propagation inside dies are used to determine the characteristics of coated wire products. As a result, comprehending the properties of polymerization mobility, heat mass ...transport, and wall stress concentration is crucial. The wire coating procedure necessitates an increase in thermal performance. As a result, this research aims to find out how floating nanoparticles affect the mass and heat transport mechanisms of third-grade fluid in the posttreatment for cable coating processes in presence of a magnetic field with time-dependent viscosity. For nanofluids, the Buongiorno model is used. The model equations are developed using continuity, momentum, and energy in the presence of nanoparticle and time-dependent variable viscosity. We propose a few nondimensional transformations that are relevant. The numerical technique Runge-Kutta fourth method is used to generate numerical solutions for nonlinear systems. Pictorial depictions are used to examine the effects of various factors in the nondimensional flow. Furthermore, the numerical results are also verified analytically using Homotopy Analysis Method (HAM). The analytical findings of this investigation reveal that within the Reynolds modeling, the stress on the whole wire surface combined shear forces at the surface predominate the Vogel model. The contribution of nanomaterials on force on the entire surface of wire and shear forces at the surface appears positive. A non-Newtonian feature can increase the capping substance’s velocity. This research could aid in the advancement of wire coating technologies. For the very first instance, the significance of nanotechnology during wire coating evaluation is explored utilizing time-dependent variable viscosity regarding the magnetic field. For time-dependent viscosity, two alternative models are useful. The Lorentzian strength (a resistive form of force) increases in magnetic strength increases. As a result of the increased magnetic field, the motion of the polymerization in a die decreases. It is clear that increasing the intensity of Nb increases the heat transfer. The innovative fragment of the present study is to scrutinize the magnetized third-grade nanofluid for wire coating with variable viscosity inside the pressurized coating die, which still not has been elaborated in the available works to date. Consequently, in the restrictive sense, the existing work is associated with available work and originated in exceptional agreement.
We develop and test a flow diagram of the process of manufacturing of rods and wires from graded loose chip wastes of eutectic silumin based on the use solely of the procedures of plastic working and ...heat treatment. In its realization, we use the method of combined rolling–pressing of preliminarily briquetted chips with subsequent drawing of pressed rods. The possibility of getting semifinished and finished products with higher levels of strength and plastic properties as compared with cast silumin is demonstrated. The specific features of formation of the structure of the material after the realization of individual stages of the general flow diagram are indicated.
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