Papers by Keyword: Drawing

Abstract: The main objective of this research was a study the simultaneous influence of cold working and particle reinforcement on mechanical properties of Al. The model composites were fabricated by cold pressing RAl1 aluminium and 5% and 10% SiC powders and hot extrusion with ratio 3.8 in isothermal conditions at 480°C with 90° die angle to 18 mm diameter. Some specimens were then cold drawn with linear velocity 1 m/min to 16% area reduction, and one specimen in 3 passes to 51% reduction in area. Mechanical properties of the near fully dense composites were determined by axial compression, bend tests and hardness measurement and their microstructures examined, showing near homogenous distribution of SiC particles in the aluminium matrix. The increase in Young’s modulus was from 67 to 74 GPa and to 82 GPa for 5% and 10% reinforcement, respectively. Drawing increased average yield strength from 70 to 100 MPa for Al, and from 74 to 110 MPa and from 80 to 115 MPa, for 5 and 10% reinforcement, respectively. The results indicate that there is a significant increase in E, in accord with the law of mixtures, through incorporation of SiC and a synergistic effect of SiC and plastic deformation during drawing on strength. An attempt is made to identify the various contributions to overall strengthening of Al by considering also Al-8.8Cu-6.3%Si-0.7Mg alloy. It appears that alloying and age-hardening have the greatest effect, but that contributions from hot, warm and cold working are not insignificant. As powder metallurgy processing is an important fabrication method, their incorporation into the processing schedule merits consideration.

Abstract: The combination of different types of deformation can create a continuous method that ensures the formation of ultrafine-grain structure in medium carbon steel wire. The method is based on drawing operation combined with torsion and bending. Tools and equipment applied in the wire and cables manufacturing are used for the implementation of this method. As a result of the combined strain effect the ultrafine homogeneous structure is formed in the medium carbon steel wire. The wire has increased strength while maintaining the plastic properties when compared with the corresponding properties after drawing.

Abstract: The microstructure, tensile properties at room temperature and corrosion rate in the 0.9% NaCl solution of the as-cast, as-extruded and as-drawn high-purity magnesium (99.99wt.% Mg) were experimentally investigated, respectively. Due to the coarse grains, both the tensile properties and corrosion resistance of the as-cast high-purity Mg were the lowest among the three states specimens, the yield strength (YS), ultimate tensile strength (UTS) and the elongation (EL) were 26.6MPa, 69.2MPa and 5.6%, respectively. The mass-loss rate of the as-cast high-purity Mg in the NaCl solution was 0.44g⋅m^-2⋅h^-1. For the as-extruded high-purity Mg, as the grains was remarkably refined, the YS, UTS and EL increased to be 108.3MPa, 152.7MPa and 27.0%, respectively, and the mass-loss rate become slower to be 0.25g⋅m^-2⋅h^-1. Attributed to the further refined grains, the YS, UTS and EL of the as-drawn high-purity Mg increased to 134.1MPa, 199.4MP and 15.3%, respectively, and the mass-loss rate reduced to be 0.12g⋅m^-2⋅h^-1. The experimental results in the present research indicated that the grain refinement can effectively improve both the mechanical properties and corrosion resistance of the high-purity Mg.

Abstract: This paper presents the theoretical foundations and methodology of the modeling process of forming a half ring alloy blank AMg5M in software product Pam-Stamp. At the following technological sizes of a half-tore: the blank radius 516.5 mm; hole’s radius R₀=480.74 mm, distance from the generating circle center to the axis of rotation R₁=714 mm, the generating circle radius R_p=93 mm, curvature radius of die R_d=16 mm, the process is stable. The results of numerical analysis of the drawing half-tore from the ring blank directed to determining the optimal process parameters are revealed. Modeling shows that the size of the holes in the blank has a significant influence on the distribution of strain along the generatrix of the stamped parts. Using the ring blank reduces the probability of wrinkling in the free areas.

Abstract: Here results of computer analysis of sinking pass of aluminum alloys in the one and two dies are widely used in aircraft construction and engineering. As a method of computer simulation of finite element method used in the program DEFORM - 2D.

Abstract: This paper proposes a method for simulation of axisymmetric cold plastic deformation processes with allowance for the microstructure of steel. The results of the method approbation relating to rod drawing process for low carbon non alloy steel (0.2% carbon) are described. A comparative analysis of the stress and strain state parameters and their distribution at macro and micro levels of a metal in the deformation zone was carried out. The micro model, in contrast to the macro model, has allowed more accurate values of stress and strain state to be obtained and multiple stress and strain localizations to be revealed due to the microstructural constituent interaction.

Abstract: The process of hollow conical forming is described for two schemes: crimp-distribution for hollow billets and stretching from sheet billet with subsequent crimping for cylindrical blank. The item thickness varying was investigated for these schemes. Dependency of technological allowance ratio on crimping coefficient and expansion ration for items allowance was investigated. The effectiveness of stretching from sheet billet with subsequent crimping was proven.

Abstract: Each enterprise that concentrates on boosting its position on a market tries to optimize mechanisms of its activity. It can be realized mainly by development in such directions as extending shares on the market, cost reduction, introducing more effective methods of production and risk management. Increasing the level of customers’ satisfaction is reached by use of FMEA (Failure Mode and Effect Analysis) as a tool of continuous development of products and processes realized by conducting their cyclic analyses. Their results build a foundation for introducing new solutions as corrective actions that eliminate causes of defects and at the same time lead to process and product improvement.The advantages of FMEA have resulted in its implementation into nearly every branch of a modern industry, both for unitary and mass production. An example of application of FMEA in mass production is a production process of beverage cans. This process is multistage, extraordinarily precise, technologically complicated and burdened by a great amount of factors that hypothetically can cause defects.The application of proper preventive actions aimed at defining both potential and factual causes of defects is an essential element of increasing the effectiveness a of production line with the simultaneous production cost reduction and boosting the level of customer satisfaction.In the article, the use of FMEA in mass production on the basis of a beverage can manufacturing has been analysed. On its basis, the potential causes of defects have been isolated and eliminated.

Abstract: Residual stress generated in the body parts during stamping process influences on its structural strength and stiffness partly. In this paper, the formality, stiffness and strength of hood-outer panel had been analysis based on Autoform and Altair-hypermesh, and the diagrams of major strain and plastic strain are shown. Compared the results by Geomagic Qualify; there are the same areas of stress concentration from the results. According to this, the body parts can be optimized to get excellent preference of stiffness and strength.

Abstract: The paper proposes the new technique of manufacturing the elongated cumulative charges (ECC); the technique was developed to advance the ECC efficiency and to reduce the production costs through lowering their manufacturing cost.