• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.563-564
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.459-460
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• 2012

• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.04a
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• pp.91-94
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• 1999

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.117-120
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• 2003

Warm deep drawing which is one of the new forming technologies to improve formability of sheet metal is applied to the cylindrical cup drawing of Mg-alloy sheet metal. In experiments the temperature of die and blank holder is varied from room temperature to $300^{\circ}C$, while the punch is cooled by circulation of coolant to increase the fracture strength of workpiece on the punch corner area. Test material chosen for experiments is AZ31 magnesium sheet metal. Teflon film as a lubricant is used on both sides of a workpiece. The limit drawing ratio as well as thickness distributions of drawn cups are investigated and validity of warm deep drawing process is also discussed.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.177-186
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• 2002

This paper describes a research work on the development of computer-aided design system far the deep drawing & ironing of high pressure gas cylinder. An approach to the design system is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories, handbook, experimental results and the empirical knowledge of field experts. This system has been written in AutoLISP on the AutoCAD Rl4.0 using personal computer. This system is composed of three modules which are input. process design and drawing.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.385-388
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• 2000

During the deep drawing process an initially flat blank is clamped between the die and the blank holder after which the punch moves down to deform the clamped blank into the desired shape. In general, sheet metal forming may involve stretching, drawing, bending or various combinations of those basic modes of deformation. The deformation problems of sheet metal working involve non-linearity in geometry and material. In this work, The punch load and thickness strain of electro-galvanized sheet steel (SECD) for elliptical deep drawing are examined under the various process conditions including, punch shape radius, die shape radius. The changes of punch load and thickness strain distribution of the deformed elliptical cup are affected by the size of each die shape radius.

• Transactions of Materials Processing
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• v.4 no.4
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• pp.345-352
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• 1995

Warm deep drawing for optimum forming conditions to give the maximum drawing depth is investigated and compared with the results from experiments performed at room temperature. Experiments which draw square cups of STS 304 stainless steel sheet under the constant lubrication condition of teflon film are made both in a crank and hydraulic press for two kinds of specimens. The maximum drawing depth at warm forming condition reaches 1.4 times the drawing depth at room temperature in a crank press, whereas 1.6 times in a hydraulic press, and also more uniform distribution of thickness in case of warm deep drawn cup is observed. The effects of other factors on formability, such as forming temperature, speed of press and cooling of punch are examined and discussed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.943-948
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• 1996

In this paper. we will discuss in making large size cylindrical shells with multithickness wall sections such as straight, stepped, tapered sides. These shells are constructed of type 6061 O temper aluminum starting with a blanking size of 877 mm plate. Its diameter to length ratio of 1 to 2.78 and a 36.7％ wall reduction is achieved by our continuous deep drawing process. This process required no in-process annealing. But after cold working, these shells is performed heat treatment to T6 condition. These shells are used for the making of seamless LPG pressure vessels after the spinning process. This process is composed of deep drawing, reverse redrawing, drawing-ironing and several ironing processes. In the verification of forming process design, we used DEFORM code.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.2
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• pp.84-90
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• 2003

Magnesium alloys have been paid attention In automotive and industries as lightweight materials, and with these materials it has been attempted at deep drawing process for assessment of formability of sheet metal. For warm deep drawing process with a local heating and cooling technique, both die and blank holder were heated at warm temperature while the punch was kept at room temperature by cooling water. Warm deep-drawing process with considering heat transfer was simulated by finite element method to investigate the improvement of deep-drawability and temperature distribution of Mg alloy sheet. The effect of sham rate sensitivity index on the deformation profile was considered in this work and the simulation results revealed that considering heat transfer is very effective for deep-drawability of Mg alloy. The deformed blank In considering heat transfer was drawn successfully without any localized thinning and the cup height is higher in contrast to results of simulations in considering no heat transfer.

• Transactions of Materials Processing
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• v.24 no.1
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• pp.5-12
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• 2015

In the current study, fundamental deep drawing characteristics of Ti-6Al-4V alloy sheets were investigated to establish the effect of processing conditions on large size square deep drawn cups. To accomplish this study, FE-simulations (Abaqus) were performed to determine optimum blank size, friction coefficient, the gap between punch and die, etc. The simulated processing parameters were verified experimentally. Based on the FE-simulation results, deep drawing was performed with various blank holding loads and sample sizes. In order to improve the formability of Ti-6Al-4V sheet, various lubricant methods were evaluated. Tensile tests and thickness measurements were conducted on the formed sheets. Processing parameters including blank holding force, lubricants, and optimum blank size, were selected to achieve improved drawing quality. With the optimum processing condition, a $200mm{\times}200mm$ cup was deep drawn successfully.