• 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.

• Design & Manufacturing
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• v.9 no.1
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• pp.1-4
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• 2015

Recently, the mold industry has been developed to high-quality and high-productivity with various demands of the high-tech industry. Also, geometry parts of injection mold are complex and diverse optimum design through the injection molding analysis has become a matter of course. The mold industry is trying to revitalize the industry with demand technology development and manufacturing process improvement. However, products that have undercut is the need for a separate processing mechanism and structure of the mold is getting more complex, the cost is expensive. Therefore, improving the structure of the mold through a study on the forced ejecting for injection molding without undercut processing unit and to improve the productivity.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.6
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• pp.1053-1059
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• 2002

The purpose of this study is to suggest how the machining technique of constant control of cutting speed can improve precision machining and tool life in high speed machining using a ball end mill. Cutting speed is changed in machining fee form surfaces such as connecting rod die. So, we don't have supreme surface form and tool life on machining. To solve this problem we should settle on optimal cutting speeds in free form surface machining. And, to improve precision machining, We must execute high speed machining methods to output optimum NC data using developed constant control of cutting speed program after modeling by CAD/CAM. In this paper, a comparison was made of the cutting precision and tool life in conventional cutting and those in connecting rod machining applying the program developed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.183-188
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• 2003

Non-molding and welding line happen by the assembly of gas at the connector terminal. There is not good phenomenon of burr by increasing the over injection pressure, the temperatures of die and resin to prevent from them. Therefore, the connector mold to apply the vacuum molding system is developed in this study. The vacuum pressure is controlled systematically with the optimum conditions in the important ingredients of injection molding that are the temperatures of melting resin and die and cooling condition. The badness in charging is cleared by making a vacuum to non-charging part of the deep bottom part of each cavity. And the vacuum system to reduce the cycle time is applied as the study envelopment of molding work. So, the good product and the productivity improvement can be obtained in this study.

• Design & Manufacturing
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• v.11 no.1
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• pp.34-38
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• 2017

Deformation frequently occurring in injection molded products is a phenomenon displayed due to uneven shrinkage distribution and orientation of the whole molded product. Shrinkage deformation is a very serious problem because it causes deformation of the molded article and shortens the performance of the product. In this paper, we are focusing on the warpage of keypad in mobile phone. In other words, we focused on minimizing keypad deformation. In the study, the Taguchi method was applied to find the injection molding conditions that minimize the deformation of the keypad. In the case of this keypad, the main factors influencing the shrinkage deformation were predicted as the melting temperature, coolant temperature and cooling time. In addition, the optimum molding conditions were obtained and the shrinkage strain was minimized. Experiments for the Taguchi method and verification of optimal molding conditions were performed using an injection molding analysis program.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.10a
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• pp.113-119
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• 2000

This study is to investigate the effects of cold forming method with steel sheet of SCP3C to improve continuous productivity. Experiments were carried out in various working conditions, such as the number of stamping and the punch temperature. The effects of the punch temperature and the number of stamping on drawability of steel sheet of SCP3C as well as clearance and draw-in in tile number of stamping were examined and discussed. The cooled the punch and the die and the blankholder heated by stamping were achieved at continuous productivity and quality improvement. The optimum forming condition for drawing trunk floor panel of SCP3C is shown as the punch is cooled by coolant of $-5^{\circ}C$ and at the same time both the die and the blankholder are heated by stamping and frictional heat,

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.946-949
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• 2003

This paper reports on the fluid flow simulation results of a multilayer type piezoelectric valve. The mechanical and fluidic analysis are done by finite element method. The designed structure is normally closed type using buckling effect, which is consist of three separate structures; a valve seat die, an actuator die and a MLCA(Multilayer Type Ceramic Actuator). It is confirmed that the complete laminar flow and the lowest flow leakage are strongly depend on the valve seat geometry. In addition, turbulent flow was occurs in valve outlet according to increase seat dimension, height and inlet pressure. From this, we was deducts the optimum geometry of the valve seat and diaphragm deflection that have an great influence fluid flow in valve. Thus, it is expected that our simulation results would be apply for piezoelectric applications such as valve and pump, fluidic control systems.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.2
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• pp.69-73
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• 2008

This article shows that the susceptibility of the device pattern to thermal stress-induced damage has a strong dependence on its proximity to the device comer in semiconductor devices utilizing lead-on-chip (LOC) die attach technique. The result, as explained based on numerical calculation and experiment, indicateds that the stress-driven damage potential of the passivation layer is the highest at the device comer. Thus, the bonding pads, which are very susceptible to passivation damage, should be designed to be located along the central region rather than the peripheral region of the device.

• Transactions of Materials Processing
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• v.27 no.3
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• pp.154-159
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• 2018

In the rectangular bar multi-stage drawing process, the cross-section dimensional accuracy of the rectangular bar varies depending on the aspect ratio and process conditions. It is very important to predict the dimensional error of the cross-section occurring in the multi-stage drawing process according to the aspect ratio of the rectangular bar and the half die angle of each pass. In this study, a process map for improving the dimensional accuracy according to the aspect ratio was derived in the drawing process of a rectangular bar. FE-simulation of the multi-stage shape drawing process was carried out with four types of rectangular bar. The results of the FE-simulation were trained to the nonlinear relationship between the shape parameters using an Artificial Neural Network (ANN), and the process maps were derived from them. The optimum half die angles were determined from the process maps on the dimensional accuracy. The validity of the suggested process map for aspect ratios 1.25~2:1 were verified through FE-simulation and experimentation.

• Journal of Korea Foundry Society
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• v.33 no.5
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• pp.204-209
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• 2013

The family mold casting have advantages which are able to make products with different shapes and dimensions simultaneously in a single mold. In this study, the design of the 4 cavity rotor family mold was used by "Anycasting" software, the defects occurred during die casting were predicted and suggested the best optimization conditions for sound products. The result of the experiment were that the optimum overflow design was needed for gas emission and control of residual oxides. It was clear that the defects positions formed by diecasting were agreed with nearly them predicted by simulation.