Key Engineering Materials Vol. 641

Abstract: In this paper, the research results of hammer forging process of titanium alloy Ti-6Al-4V are described. It is hard deformable alloy so forming details with complex shape from this alloy requires precise selection of thermomechanical parameters. Proper design of technological forging process of forging from Ti-6Al-4V alloy, taking into account the initial metal working, shape of supportive impressions, lubricants with proper tribological properties and also proper selected temperatures of tools and material allows to get the final product without defects. The numerical modelling based on the FE software QForm 3D was carried out. The distributions of temperature, effective strain and material flow kinematics were analyzed. The correctness of the modelling results was verified by the forging test performed in industrial conditions. Hammer forging tests were made in Polish forging plants. The products of good quality were obtained.

Abstract: Modern manufacturing technologies of flat cold-rolled products made of aluminium and its alloys are based on raw materials produced with the use of continuous casting technology. One of the most frequently used integrated production processes, based on continuous casting of metal, is twin roll casting method (TRC). In TRC method liquid metal flows into the area formed by two water-cooled rolls, solidifies and next is deformed (rolled) which allows to obtain strip with several millimetres thickness. Thanks to this, it is possible to eliminate hot rolling stage from the typical production technology, and directly subject obtained sheets to cold rolling process.This paper presents results of cold rolling strain dependency on the mechanical properties of tested aluminium alloys from 1XXX, 3XXX and 8XXX series, produced in the laboratory conditions with the use of TRC method. Furthermore the rolling loads and basic mechanical properties, determined in an uniaxial tensile, were examined.

Abstract: Magnesium is the lightest metal used for construction elements. Due to their lightness and good mechanical properties magnesium alloys have been used in aviation industry since 50’s of the last century. Magnesium – Lithium alloys are the lightest of all magnesium alloys. Their density can be lower than 1,0 g/cm³. In this paper the results of numerical simulation of direct extrusion of Mg-Li alloy hollow profile are presented. The alloy has 12% addition of Lithium and has been extruded through porthole dies. The analysis of temperature distribution, metal flow and stress and strain with the use of Finite Element Method (FEM) have been calculated in Deform 3D software. The mathematical simulation have been performed for various ingot temperatures and the die’s geometry. Thanks to numerical simulation, the optimal temperature and die geometry have been determined and due to this fact the optimal stress conditions in a welding chamber have been obtained

Abstract: Numerical simulations of drawing and redrawing process of forming cylindrical elements from thin sheets are complicated issues due to the problem with describing finite elements in the complex calculation model. This type of simulation require the creation of the rheological model including the forming limit curve, the true-stress-strain curve and anisotropy defined in various directions. In addition, it is necessary to design optimal geometry of the forming tools. FEM calculations have been performed for 3XXX series aluminum tape in cold-hardening state. The initial data, boundary conditions have been defined, as well as technological data concerning the sheets have been specified experimentally. Numerical analysis of thin aluminum sheet drawing and redrawing process has been analyzed for 3 various sheet thicknesses, i.e.: 0,250 mm , 0,240 mm , 0,230 mm. Currently, the industry uses mainly sheets of 0.250mm thickness. A few manufacturers of beverage cans use sheets of thickness0.240mm while the sheet of thickness 0.230mmis the innovation which manufacturers try to introduce into the industry to minimize the quantity of material. For the selected thickness the clearance between the punch and the die has been calculated as well as the optimum hold-down force. The influence of sheet thickness on the distribution of thinning along generating line has been examined. In order to determine the thinnest possible sheet for obtaining the optimal thickness of the final product, the thinning of drawpiece has been analyzed. Moreover the value of deformations has been compared to FLC curve as well as the intensity of the stresses generated in the bottom and on side walls of the cup has been examined.

Abstract: In industrial practice, where the amount of products produced in a minute is calculated in hundreds of units, the ironing process of thin-walled cylindrical shell products is carried out with very high speed. In the multi-stage forming process it is important to ensure the stability of parameters of the raw material. Properties of input sheets are defined in international standards, but after the rolling process the properties of input tapes may be various while still in the acceptable tolerance. Differentiation of properties of sheets has a significant impact on the progress of the examined process. The multi-stage forming process requires raw material with a high susceptibility to deformation and an adequate level of plasticity margin. In this study tapes of equal thickness and similar chemical composition from various suppliers have been analyzed. Selected aluminum alloys sheet are currently used in Europe in production of beverage packaging. On the basis of uniaxial tension test results, plasticity margin for a selected tape has been determined. Deformation range and plasticity margin have been analyzed in relation to the stability of production process Defining the correlation between identified strength parameters and the stability of production line allowed to examine the impact of plasticity margin for effectiveness and efficiency of the process. In mass production, each break in machine work results in loss of millions of units. The analysis allowed to compare the value of plasticity indicators of the raw tape deformability in the complex process of forming thin-walled cylindrical shell products and influence for increase the efficiency and reduction of defects.

Abstract: Materials used for the production of aluminum beverage cans must meet strict strength and plastic requirements. Meeting these requirements by manufacturers ensures minimization of defects in optimized production line, trouble-free operation and good efficiency of production. Depending on some factors, such as: chemical composition of the 3104 aluminum alloy, sheet rolling method, lubricant layer and cooling method, the final product may be characterized by different mechanical parameters. In this study properties of six types of sheets from four different suppliers have been measured. Thickness distributions have been analyzed both on the width and length of the supplied coils. Sets of samples have been prepared for the research, cut out from the coil in three directions 0°, 45° and 90° of the rolling direction. On the basis of the uniaxial tension tests, yield strength, tensile strength, elastic modulus and elongation have been determined. The results have been summarized taking into account their variable values depending on sampling directions. Forming limit curves have been defined for the examined sheets. In order to identify the effect of selected data on wall thickness of both final and semi-products, thickness measurements have been conducted for the drawn cups and cans on different forming stages.

Abstract: The paper presents the results of a study to designate the optimal conditions for the powder mixtures extrusion through porthole die to ensure high quality welds. Conditions for obtaining the profiles of powder mixtures with a high degree of compaction and good quality welds have been determined based on mathematical and physical modelling. Modelling studies have been confirmed in laboratory and industrial trials.

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: The study is aimed at comparing the changes which occur in the microstructure and thermo-physical properties of pure copper (99.9%) and when copper alloyed with chromium and zirconium subjected to severe plastic deformation (SPD). The plastic deformation techniques employed were hydrostatic extrusion (HE), equal channel angular pressing (ECAP), and a combination of these two processes. The materials thus obtained had an ultra-fine-grained structure with the thermo-physical properties differing from those of the untreated materials. It appeared that there is a correlation between the deformation method employed and the thermo-physical properties of the materials, such as diffusivity and specific heat.

Abstract: The present study attempts to apply Equal-Channel Angular Pressing (ECAP) to 99.99% pure copper. ECAP process was realized at room temperature for 4, 8 and 16 passes through route B_C using a die having angle of 90^°. The microstructure of the samples was investigated by means both light and transmission electron microscopy. Additionally the microhardness was measured and statistical analysis of the grains and subgrains was performed. Based on Kikuchi diffraction patterns misorientation was determined. There were some different types of bands in the microstructure after deformation. The shear bands, bands and in the submicron range the microshear bands and microbands are a characteristic feature of the microstructure of copper. Also characteristic was increasing of the number of bands with increasing of deformation and mutually crossing of the bands. The intersection of a bands and microbands leads to the formation of new grains with the large misorientation angle. The measured grain/subgrain size show, that the grain size is maintained at a similar level after each stage of deformation and is equal to d = 0.25 – 0.32 μm.