Showing 10 results for Deep Drawing
Abozar Barimani, Seyed Jamal Hosseinipour,
Volume 14, Issue 10 (1-2015)
Abstract
Aluminum alloys are using widely duo to high strength-to-density ratio in the industries of automotive, shipbuilding and aerospace as a substitution of steel sheets. .To increases the formability of aluminum alloys in deep drawing process and due to formability problems of these alloys in room temperature using of warm deep drawing process is necessary. According to recent researches, warm deep drawing in gradient condition has better results as isothermal case. In this paper the process parameters in production of cylindrical parts from aluminum alloys 5083 sheet with 2mm thickness is investigated. For this purpose, gradient warm deep drawing in temperatures of ambient (25˚C), 80˚C, 150˚C, 180˚C, 250˚C, 350˚C , 450˚C and 550˚C have been used. The blank in flange region is heated by die heating and the blank center to increases the strength of the region which contact with punch corner radius is cooled by water circulating punch. The results show that increasing the temperature of the blank in flange region and also cooling of blank center lead to improve the limit drawing ratio. In forming temperature of 550˚C and ram speed of 378 mm/min and lubrication by graphite powder can reach to the limit drawing ratio equal to 2.83.
Behrooz Zareh-Dsari, Mohammad Abaszadeh, Behnam Davoodi,
Volume 15, Issue 1 (3-2015)
Abstract
Lubrication is an essential factor in sheet metal forming processes such as deep drawing in order to reduce friction at contact surfaces, forming load, tool wear rate and increasing of sheet formability. Various metal oxide nanoparticles can be used as additives to create desirable tribological properties in base lubricants because of their unique properties such as specific surface area. In the present study, the conventional lubricant enhanced by alumina nanoparticles (Al2O3) is utilized in deep drawing process in order to improve frictional conditions. The forming load, surface roughness (Ra) and thickness distribution values of the formed cups were assessed to evaluate the performance of the enhanced conventional lubricant with alumina nanoparticles (Al2O3) in comparison to the conventional lubricant and dry forming condition. The obtained results from experimental tests revealed that adding 0.5 wt.% Al2O3 nanoparticles to the conventional lubricant improves lubrication property significantly and reduces forming load by 16.39% and surface roughness by 19.33% compared to the conventional lubricant. Furthermore, it is observed that using lubricant containing nanoparticle additives results in 23.94% improvement in maximum thickness reduction in critical zone.
Abdolhamid Gorji, Esmaeil Mohammadian, Mohammad Ali Mirzai,
Volume 15, Issue 4 (6-2015)
Abstract
Forming media in metal forming processes is so important. Since the forming media in Ball deep-drawing process is discrete, it is quite flexible. In this paper, thickness distribution and required force for forming of conical part by ball deep-drawing and conventional deep-drawing processes using finite element simulation and experimental stages, were studied. In this research, sheets were used made St14 steel and brass wit 1mm thickness. The experimental results are in good agreement with simulation results. The results showed the sample formed by conventional deep-drawing process had more uniform thickness distribution than ball deep-drawing, but the maximum thinning in the parts of ball forming process was less than conventional deep-drawing process. Also it was observed that required force for ball deep drawing process is more than the conventional deep-drawing process. It was observed that with increasing radius of the input die, the force required to stretch the ball deep-drawing and ball processes is decreased, also with increasing radius of the input die is reduced thinning amount. It was noted that one of the advantages of ball deep drawing process than traditional deep drawing process is achieved a negative slope part.
S.m.h. Seyedkashi, Farzad Rahmani, Hossein Amirabadi, Mohammad Hoseinpour Gollo,
Volume 16, Issue 11 (1-2017)
Abstract
In hydromechanical deep drawing process, the traditional matrix is replaced by pressurized fluid, and the final shape is determined based on the shape of a rigid punch. It is required to change the fluid pressure within the allowed working zone during the process to prevent the workpiece from rupturing and wrinkling,. Working zone curve represents the range of maximum available drawing ratios without rupture under the highest chamber pressure. In this paper, hydromechanical deep drawing of square cups made of aluminum-steel double layer sheets are studied by experiments and finite element simulations. In order to detect the rupture onset in simulations, experimental forming limit diagrams were obtained using for aluminum/steel double layer sheet. Experimental data were used to validate the finite element model. The effects of process parameters such as thickness of the various layers, prebulge pressure, chamber pressure and the friction coefficient were investigated on the working zone and the process window. The numerical results show that an optimum amount for the drawing ratio exists for each prebulge pressure. Also, with increasing the chamber pressure, shrinkage is reduced on the flange area. With increasing the friction between the sheet and matrix or the sheet and blank-holder, working zone becomes smaller; while with increasing the friction between the sheet and the punch it becomes larger. Experiments were performed for different drawing ratios to evaluate the numerical results, in which a good agreement was observed.
Majid Molaei, Hamed Deilami Azodi, Mehdi Safari,
Volume 17, Issue 3 (5-2017)
Abstract
Hydro-mechanical deep drawing is an advanced process in metal forming in which high pressure fluid is used to form complicated parts. Conical parts are kind of complex parts in which there is a high possibility of thinning and rupture during the forming process due to low contact area between the punch head with the blank. In this paper, the Hydro-mechanical deep drawing of Al3003-IF Steel two-layer conical parts is studied using the experimental and numerical approaches. The effects of process parameters such as friction coefficient, arrangement of layers and thickness ratio of two-layer sheet on working zone are investigated. Allowable working zone in this process indicates the applicable range of chamber pressure and drawing ratio to achieve a part without rupture. The results show that with decreasing the friction between blank and blank holder, increasing the friction between blank and punch, increasing the thickness of high formable layer and setting IF steel layer as outer layer increase the limit drawing ratio and make the allowable working zone more extensive. Finally comparison of the results obtained from experimental investigation and numerical simulation shows a good agreement between the results.
Mohammad Pakdaman, Abdolrahman Jaamialahmadi,
Volume 17, Issue 10 (1-2018)
Abstract
In this article, the influence of process parameters on warm deep drawing of PVC/fiberglass composite laminates (FRP) is investigated through the experimental tests. Fiberglass reinforced polymer (PVC) composite laminate sheets are new emerging materials that have many potential applications. FRP/composites provide high strength to weight ratios exceeding those of aluminum or steel. For the experimental tests, composite samples with [0/90]2, [0/90]4, [-30/30]2, [-30/30]4 lay ups were produced in using film stacking procedure. Statistical analyses based on Taguchi's method are used to reduce the number of experiments and to investigate the effect of process variables on the output results. The results show that the two variables of temperature and blank holder force have the most influence on output parameters. Furthermore they demonstrate that a high interaction between the forming temperature and blank-holder force is required to remove the wrinkling.
Seyed Mohammad Ebrahim Alinaghi-Maddah, Seyed Jamal Hosseinipour, Mohammad Bakhshi-Jooybari,
Volume 18, Issue 8 (12-2018)
Abstract
Aluminum alloys have become widespread in the various industries due to the characteristic of high strength-to-density ratio. These alloys do not have a suitable formability at ambient temperature so they formed at high temperatures. The main hot forming methods used for aluminum alloys include deep drawing and gas forming. Both of these methods have their own advantages and disadvantages. In this study, a combined process involving deep drawing and gas forming has been used. In this process, the first step is to create a pre-formed deep drawing and in the second stage, the final piece is produced by gas forming process. The purpose of this study is to optimize the levels of the main process parameters for the shaping of cubic parts of aluminum sheet 5083 sheet. These parameters include the temperature and blank-holder force of deep drawing stage and the temperature and gas pressure at the gas forming stage. The best levels of process parameters were selected using the Taguchi experimental design method. The results show that the temperature at 350 ° C and the blank-holder force of 1000 N for deep drawing, as well as the temperature of 485 ° C and the gas pressure of 0.6 MPa for the gas forming stage, can be achieved with the least degree of thinning in the specimen. The maximum thinning achieved is 22%.
A. Sanatiean, A. Saghafi, H. Rastegari Koupaei,
Volume 20, Issue 6 (6-2020)
Abstract
Deep drawing process is one of the most important processes of sheet forming, which is widely used in the deformation of metal sheets in order to produce parts with complex geometry. Several studies have been carried out on some steels with good formability such as low-carbon and austenitic stainless steels. Among different types of plain carbon steels, high carbon eutectiod steels are capable to withstand cold and warm working without formation of any defect, due to their fully pearlitic microstructure without the presence of proeutectoid phases and nano-sized cementite lamella. However, no comprehensive research has been conducted on the deep drawing process of eutectoid steel. In the present research, the formability of CK75 steel sheets was experimentally evaluated using warm deep drawing process. Warm deep drawing process of the CK75 steel was studied in the temperature range near and below the eutectoid transformation temperature. The results show that deformation at 700°C (near to the eutectoid temperature) lead to the uniform distribution of thickness and less instability. On the other hand, maximum instability (e.g. thinning) was obtained by warm deformation at 550°C. At the temperature above the eutectoid transformation temperature, due to the formation of multi-phase structure and non-uniform distribution of cementite particle, the workability was reduced and led to the occurrence of rupture during deep drawing.
M. Khalili, M. Bakhshi Jooybari, H. Gorji,
Volume 20, Issue 10 (10-2020)
Abstract
Research results performed by researchers have illustrated that applying electric current to a deforming metal can lead to a reduction in the required deformation force and an improvement in the formability. This technique is known as electrically assisted forming and is used in various forming processes. In this paper, the forming of square cups through electrically assisted deep drawing process was investigated experimentally and the effects of process parameters, including current magnitude, pulse frequency, and waveform (sinusoidal and square) on the forming force, thickness distribution, and drawing depth are examined. In this regard, after designing and preparing the test setup and forming square cups, the experimental results obtained were compared to those of the conventional deep drawing tests. The results showed that increasing the current magnitude leads to reducing the maximum thinning and the forming force in the deep drawing process of the formed parts. Furthermore, it was found that at a higher frequency, the deformation force decreases significantly and thickness distribution becomes more uniform. The comparison of the two waveforms of pulses demonstrated that the sinusoidal waveform has a relatively more significant effect on the reduction of the force and thickness distribution and a considerable effect on the drawing depth.
Seyyed Amir Ahmadian, Moein Taheri, Mehdi Modabberifar, Ali Jabbari,
Volume 21, Issue 7 (7-2021)
Abstract
Deep drawing is one of the sheet forming processes, in which a metal sheet with mechanical operation, reaches the desired shape. One of the most important issues in deep drawing is the optimal design of the initial blank. In this paper, the main purpose is to design the optimal initial blank (with minimum circumference and minimum defects), for deep drawing of parts with a rectangular cross section. To this end, in this study, a program in Visual Basic has been written in SolidWorks software, in which a rectangular piece and press velocity variables take the tensile depth as input and design the optimal blank. Also in this program, blanks with rectangular, circular, octagonal and rhombus contours have been obtained; So that they are tangent to the initial contour. A separate program has also been written to display contour blanks at different times. The blank design program obtained in this study has this unique feature that for any type of rectangular piece and with any desired dimensions, according to the dimensions of the piece and the depth of tension, it will be possible to design the optimal blank. To ensure the accuracy of the program written in Visual Basic language, the results of the program have been compared and validated by performing experimental work. Experimental results prove that the blanks obtained by the program are of acceptable accuracy. In experimental parts, defects such as earring and shrinkage have also been observed in parts produced with optimal blanks.
