Potentials of an adaptive blank positioning to control material and process fluctuations in deep drawing

Deep Drawing (DD) process is the one in which a punch forces a flat sheet metal blank into a die cavity. DD can also be described as the process which involves conversion of flat thin sheet metal blanks into parts of desired shape. Little work is available in the applications of DD processes at elevated temperatures which is going to be a very important manufacturing application in the coming decades. Deep Drawing (DD) is one of the sheet metal forming processes widely used in automobile, aerospace, electronics and allied industries to produce the hollow parts. The improvement in the deep drawing manufacturing process with latest methodologies leads to developments in the automobile and other sheet metal industries. Still today, this process of analysis and design is an art than science. Presently, the conventional deep drawing (CDD) operation is carried out at room temperature in industries. Although the deep drawing process of high strength / low formability metals has an extensive industrial application area, deep drawing at room temperature has serious difficulties because of the large amount of deformations revealed and high flow stresses of the materials. The present paper gives an overview of deep drawing process, its classification along with advantages, limitations and applications.

Cross-profile deep drawing of magnesium alloy AZ31 sheet metal for springback analysis under various temperatures

A study of vibro-acoustic behaviour variation of thin sheet metal components manufactured through deep drawing process

This study was the use of the finite element method in the deep drawing process of a rectangular shell cup. The aim was to analyse the equivalent strain in the workpiece and to find out what happened to the disc blank sheet before the forming by stamping. The rectangular shell cup was 24x30x20 mm. and made of 2mm.thick SUS 403 and SUS 304 stainless steel. There were 3 types of blank sheets: 1) square sheet 2) 45 degree angled edge cutting sheet 3) circular sheet. It was found out that the drawing up with the use of 3 types of blank sheet made of SUS 304 stainless steel had no risk in the workpiece. For the stamping of the rectangular shell that used a square sheet made of SUS 403 stainless steel, it was found out that there was no risk in the work piece, but with the use of 45 degree angled edge cutting sheet or round sheet, the work piece had a risk to be damaged. Keywords: rectangular shell, Finite element 1. INTRODUCTION Deep drawing is very important to component manufacturing of parts of a product in industries. The problem of the rectangular shell cup deep drawing process was the equal amount of flow in each side, resulting in making mould in an actual production process. Therefore, finite element process plays a role in analyzing the ability of a rectangular shell deep drawing process and it well known that using steel sheet in deep drawing process requires an awareness of the factors that have an effect with finished workpieces to prevent the damage that may happen with workpieces during the deep drawing process There are the factors or variable that have an influence on ability in drawing. During the deep drawing, the punch will be stamped on the blank sheet through the die opening. This process will make the bending and unbending in the die. The metal between the punch will have tensile stress along the line of the punch and the hoop compression stress. The metal on the shell wall will receive axial tension. At the bottom of the shell the metal will have tensile stress on both axial lines. This stress has an effect to the force in drawing and damage that will be

Forming conical parts is one of the difficult fields in sheet metal forming processes. Because of low contact area of the sheet with the punch in the initial stages of forming, too much tension applied to the sheet that it causes bursting. Furthermore, since the major part of the sheet surface between the blank holder and punch tip is free, wrinkles appears on the wall of the drawn parts. These parts are normally formed in industry by processes such as spinning, explosive forming or multistage deep drawing. Hydroforming deep drawing is one of the special deep drawing processes which have been introduced in order to overcome some inherent problems in the conventional deep drawing with rigid tools. In the present work, an experimental program has been carried out to form and compare the forming pure copper conical-cylindrical cups by hydroforming and conventional multistage deep drawing processes. The conical parts in conventional deep drawing process formed in two stages. The results of the study demonstrate that thickness distribution are more uniform in the parts formed by hydroforming compared to conventional multi stages deep drawing processes.

Texture evolution of the deep drawing of molybdenum sheet was investigated with EBSD (Electron Back Scattered Diffraction), X-ray diffraction techniques and orientation distribution function (ODF) analysis. The texture during deep drawing is hardly changed due to the strong of initial texture. Specimens symmetry of 45° from rolling direction have monoclinic symmetry during deep drawing proce ss. EBSD can be used for the quantitative determination of macroscopic texture as like X-ray diffraction techniques if a sufficient number of grains are measured. Grain sizes show the similar values during deep drawing process but their values along 45° direction from rolling direction at flange and wall are tend to increase. It is associated with the 45° earing of deep drawing processing. The correlation function values were -0.58 for RD flange and -0.36 for RD wall and suggest that high Taylor factor regions have low pattern quality and low Taylor factor regions have high pattern quality.

In deep drawing processes, the use of lubricants is mandatory in order to prevent wear on tools and surface damage to the formed sheet metal components. Here, frequently used lubricants are synthetic and mineral oils, emulsions, and waxes. However, these conventional lubricants have to be applied to the sheet material prior to the forming operation and removed afterwards by cleaning processes. Additionally, the lubricants often contain substances that are harmful to the environment and to human health. To counteract these economic and ecological disadvantages, research is currently being conducted on a novel tribological system. For this, volatile media such as liquid carbon dioxide and gaseous nitrogen are being used, and are introduced directly into the friction zones between the tool and the sheet metal material during deep drawing under high pressure through special laser-drilled micro-holes. This paper covers the latest investigations and findings regarding the design of flow-optimized micro-holes, the laser drilling process, the friction characterization on tool radii, and the tool wear to be expected when using the lubrication medium CO2.

In this paper, the traditional empirical coefficient method and a novel loop material analytical method presented by the authors have been compared and discussed by analyzing several practical cylindrical workpieces’ deep drawing projects. Also, some conclusions about how to modify the traditional analyzing method of cylindrical workpieces’ deep drawing process could be concluded and the necessity of this modification could be proved.

Deep drawing is characterized by extremely complex deformation that is influenced by process characteristics such as die and punch shapes, blank shape, blank holding force, material properties, and lubrication. The optimization of the deep drawing process is a challenging issue due to the complicated functions that define and relate the process parameters. However, the optimization is essential to enhance the productivity and the product cost in the deep drawing process. In this paper, a MATLAB toolbox (Pattern Search) was employed to minimize the maximum deep drawing force (Fd-min) at different values of the operating and the geometrical parameters. As a result, a minimum deep drawing force chart (carpet plot) was generated to show the best combination of friction coefficients at the blank contact interfaces. The extracted friction coefficients guided the selection of proper lubricants while minimizing the deep drawing force. A finite element analysis (FEA) was applied through 3D model to simulate the deep drawing process. The material modeling was implemented utilizing the ABAQUS/EXPLICIT program with plastic anisotropy. The optimization results showed that the deep drawing force and the wrinkling decrease when compared with experimental and numerical results from the literature.

Abstract. A promising approach to meet ecological and economical challenges in production industry is the combination of additive manufacturing and forming, which enables the production of hybrid parts. The fusion of the two technologies has the potential to use the benefits of both process classes. One example for the combination of additive manufacturing and forming is a process chain consisting of laser-based directed energy deposition (DED-LB/M) to apply a wear resistant coating on a sheet metal and a subsequent deep drawing process to achieve the final geometry of the component. However, the presence of the local reinforcement influences the subsequent sheet metal forming process. In order to gain more knowledge about the process chain a numerical approach is performed. In this work, the influence of a coating using Bainidur® AM applied by DED-LB/M on the formability of the case hardening steel 16MnCr5 in a deep drawing process is evaluated. For this purpose, a numerical model is built and validated by comparison with experimental results. The finite-element-model serves as the basis for the investigation on the influence of the location of the additively applied coating on the deep drawing process and also enables a deeper understanding of the process.

The deep drawing process is commonly used in the industry because its ability to produce parts with reduced weight and good mechanical properties at a high production rates. However, the elasto-plastic deformation mechanism of deep drawing is complex and difficult to analyse; this because there are many process parameters and variables involved that affect the quality of final products. Among these variables are the geometric parameters, which have been proved to have a great influence on the process. Theoretical and experimental analyses reported in the literature have been mainly focused on conventional cylindrical cup deep drawing. Few research works have dealt with the deep drawing analysis of non-cylindrical parts, particularly the influence of geometrical parameters on the deep drawing performance. This paper presents an analysis of the effect of geometrical parameters on the allowable deep drawing height (DDH) of rectangular parts before fracture. The aim is to identify the influence of the main geometrical parameters on the DDH, Numerical analyses based on the Finite Element Method (FEM) were used to investigate the influence of geometrical parameters, such as the radii, the metal sheet thickness, and the aspect ratio, among others, on the DDH.

This article represents the most common sheet formation method, deep drawing. This technology is employed in the production of the automotive and aerospace industries. There are various aspects that have an impact on the deep drawing process; these factors are known as the deep drawing process parameters. Finite element analysis and Taguchi Techniques are coupled to find out the optimum deep drawing parameters. Six process parameters such as die corner radius, punch corner radius, punch speed, friction between blank and die, friction between blank and blank holder and friction between blank and punch are used for analysis. Punch force is considered as response variable. The Taguchi method is employed to determine the optimal process parameters for the deep drawing process. Based on SN ratio analysis, optimum deep drawing parameters for punch force were found to be die corner radius of 7mm, punch corner radius of 7mm, punch speed of 0.2mm/s, friction between blank and die of 0.08, friction between blank and blank holder of 0.08 and friction between blank and punch of 0.10. From ANOVO, it was found that die corner radius was the most significant process parameter influencing minimum punch force.

Deep drawing process is one of the important processes in sheet metal forming. One of the challenge that faces the deep drawing process is selecting the optimal values of process parameters for the deep drawing process. In order to find the optimum values of these parameters, it is necessary to study their influence on the deformation behaviour of the sheet metal. This paper develops a simulation model for deep drawing process based on Simufact sheet metal forming module to study the effect process parameters on the deep-drawing characteristics. The study also obtained the distribution of strain on the drawn product. Three process parameters are considered in this study namely, punch radius, die radius and clearance, the effect of these process parameter on the required force as well as on the quality of the product are investigated.

This paper introduces an optimized microridge-punch design for deep-drawing processes with improved formability and punch service life. Reducing the thickness of metal sheets results in a marked decrease in the microscale/mesoscale deep drawing rates. Prior studies have recognized that the drawing punch with a microridge design next to the punch nose lowers the thinning rate and improves the deep-drawing formability. However, the increased stripping force associated with the microridge design may result in deformation of the drawn cup and shorten the punch service life. Here, we present a parameter optimization of the microridge design, in which there is a tradeoff between multiple objectives in the deep-drawing process. We introduce a fuzzy inference to synthesize two design objectives, i.e., the thinning rate and stripping force, into single design fitness. We use Deform-2D software to simulate deep-drawing performance for design optimization. Since the simulation of design objectives is computationally expensive, we introduce a novel sequential surrogate-based optimization to improve the sampling and searching efficiencies. The proposed optimal microridge design outperforms the best design for both the thinning rate and stripping force of all the samples, as well as the design obtained by the Taguchi method based on the fuzzy design fitness. Compared with the Taguchi design, the proposed optimum design improves the fuzzy design fitness by 29.2%, whereby the stripping force is significantly reduced by 35.2%, with only a slight 2% increase in the thinning rate. The proposed design effectively ensures both the deep drawing formability and the microridge-punch service life.

Numerical Analysis On The Effect Of Various Parameters On Fracture Limit For Deep Drawn Cups