• Design & Manufacturing
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• v.13 no.3
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• pp.35-40
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• 2019

As the consumer market in the cosmetic, vehicle manufacturing and aerospace industries grows, the demand for manufacturing industries using on injection mold technology. Also, such manufacturing technology of metal machining is expensive, and the shape is limited. Cosmetic cushion fact products are divided into outer relevant to the exterior of the product and inner containers containing the actual contents. In the case of the inner container, it needs to be combined with the upper and lower cases. As environmental regulations are strengthened internationally, the use of a large number of component parts can result in significant losses in recycling and economics. Therefore, this study aims to perform injection molding analysis through injection molding simulation to develop a cushion fact container that can be recycled through the unification of products and materials using polypropylene to cope with environmental regulations. In the case of injection molding conditions, Injection Time(sec): 4.5, Cooling Time(sec): 13, Resin Temperature($^{\circ}C$): 240, and Pressure(MPa): 30 were determined. The results of injection molding simulation according to the two design methods were compared with the sync mark which shows the problem of filling and injection molding.

• Design & Manufacturing
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• v.6 no.2
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• pp.64-69
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• 2012

This study looks at plastic mold design for robots and mold manufacture, which is an injection mold branch at The Korea-China-Japan University Grand Prize Contest. Product analysis and layout, molding analysis, and upper and lower core design are carried out to design molds in 2D and 3D. After the design of the cores, NC machining software is used for simulation before actual manufacture. Before the production of end-product, test injection is done to troubleshoot problems like bad dimensions, burr, cracks and stepped pulley.

• Journal of Powder Materials
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• v.9 no.4
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• pp.227-234
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• 2002

For the austenitic stainless steel (304L) manufactured by metal injection molding(MIM), the effects of copper content and sintering temperature on the mechanical properties, antibacterial activities, corrosion resistance, and electric resistances were investigated. The specimens were prepared by injection molding of the premixed powders of water-atomized 304 L and Cu with poly-acetyl binders. The green compacts were prepared with various copper contents from 0 to 10 wt.% Cu, which were debound thermally at 873 K for 7.2 ks in $N_2$gas atmosphere and subsequently sintered at various temperatures from 1323 K to 1623 K for 7.2 ks in Ar gas atmosphere. The relative density and tensile strength of the sintered compacts showed the minimum values at 5 and 8 wt.% Cu, respectively. Both the relative density and the tensile strength of the specimen with 10 wt.% Cu sintered at 1373 K showed the highest values, higher than those of copper-free specimen. Antibacterial activities investigated by the plastic film contact printing method for bacilli and the quantitative analysis of copper ion dissolved in water increased as the increase of the copper content to stainless steels. It was also verified by the measurement of pitting potential that the copper addition in 304 L could improve the corrosion resistance. Furthermore the electric conductivity increased with the increase of copper content.

• Journal of Powder Materials
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• v.23 no.1
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• pp.26-32
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• 2016

Powder injection molding (PIM), which combines the advantages of powder metallurgy and plastic injection molding technologies, has become one of the most efficient methods for the net-shape production of both metal and ceramic components. In this work, plasma display panel glass bodies are prepared by the PIM process. After sintering, the hot isostatic pressing (HIP) process is adopted for improving the density and mechanical properties of the PIMed glass bodies. The mechanical and thermal behaviors of the prepared specimens are analyzed through bending tests and dilatometric analysis, respectively. After HIPing, the flexural strength of the prepared glass body reaches up to 92.17 MPa, which is 1.273 and 2.178 times that of the fused glass body and PIMed bodies, respectively. Moreover, a thermal expansion coefficient of $7.816{\times}10^{-6}/^{\circ}C$ is obtained, which coincides with that of the raw glass powder ($7.5-8.0{\times}10^{-6}/^{\circ}C$), indicating that the glass body is fully densified after the HIP process.

• Design & Manufacturing
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• v.17 no.1
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• pp.48-55
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• 2023

In this study, on the structure simulation for manufacturing a high strength/light weight 48V battery housing for a mild hybrid vehicle was conducted. Compression analysis was performed in accordance with the international safety standards(ECE R100) for existing battery housings. The effect of plastic materials on compressive strength was analyzed. Three models of truss, honeycomb and grid rib for the battery housing were designed and the strength characteristics of the proposed models were analyzed through nonlinear buckling analysis. The effects of the previous existing rib, double-sided grid rib, double-sided honeycomb rib and double-sided grid rib with a subtractive draft for the upper cover on the compressive strength in each axial direction were examined. It was confirmed that the truss rib reinforcement of the battery housing was very effective compared to the existing model and it was also confirmed that the rib of the upper cover had no significant effect. In the results of individual 3-axis compression analysis, the compression load in the lateral long axis direction was the least and this result was found to be very important to achieve the overall goal in designing the battery housing. To reduce the weight of the presented battery housing model, the cell molding method was applied. It was confirmed that it was very effective in reducing injection pressure, clamping force and weight.

• The korean journal of orthodontics
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• v.50 no.6
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• pp.401-406
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• 2020

Objective: To investigate and compare the slot sizes and parallelism of metal injection molding (MIM) and computerized numerical control (CNC) brackets. Methods: The following four MIM bracket series with 0.022-inch (in) slots were selected for investigation: Di MIM mini Twin (Ortho Organizers), Mini Diamond Roth (Ormco), Gemini MBT (3M Unitek), and Formula R Roth (Tomy). The following four CNC bracket series with 0.022-in slots were selected for investigation: Econoline MBT (Adenta), Legend mini MBT (GC Orthodontics), Crown mini MBT (Adenta), and Evolve MBT (DB Orthodontics). The slot dimensions were measured using an optical microscope (XTCam-D310M; Mitutoyo) with a resolution of 1 ㎛. The results were statistically analyzed using one-way analysis of variance and the Tukey post-hoc test with a significance level of 0.05. Results: The results indicated that all the investigated slot sizes were oversized with respect to the manufacturers' specifications (0.022 in). Among the eight bracket series, the Di MIM bracket (MIM) was the most oversized by 10.4%, whereas the Evolve bracket (CNC) was the least oversized by 2.6%. The slots in seven of the bracket series had divergent walls instead of parallel ones. The Evolve bracket alone had parallel slot walls. Conclusions: Regardless of the manufacturing method, all the slot sizes of the brackets investigated in this study were significantly oversized; most of the slot walls were nonparallel, except for those of the Evolve bracket. This study could not establish that the CNC method was more accurate than the MIM method in manufacturing bracket slots.

• Journal of Powder Materials
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• v.30 no.1
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• pp.1-6
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• 2023

High-entropy alloys (HEAs) are attracting attention because of their excellent properties and functions; however, they are relatively expensive compared with commercial alloys. Therefore, various efforts have been made to reduce the cost of raw materials. In this study, MIM is attempted using coarse equiatomic CoCrFeMnNi HEA powders. The mixing ratio (powder:binder) for HEA feedstock preparation is explored using torque rheometer. The block-shaped green parts are fabricated through a metal injection molding process using feedstock. The thermal debinding conditions are explored by thermogravimetric analysis, and solvent and thermal debinding are performed. It is densified under various sintering conditions considering the melting point of the HEA. The final product, which contains a small amount of non-FCC phase, is manufactured at a sintering temperature of 1250℃.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1333-1334
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• 2010

• Design & Manufacturing
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• v.11 no.2
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• pp.9-14
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• 2017

The design and manufacturing tehcnology of IC sockets beyond 0.3mm pitch were presented. We compared the developed IC socket with the conventional one especially on the core metal-insulation part. Advanced machining techniques were employed to provide high precision. Our wire electrodischarge machining and high speed machining centers were able to maintain the micro-scale precision. We performed an injection molding analysis using a commercial analysis tool to predict the performance of the developed IC socket. We found that the solidification of the plastic resin and the high level of the clamping force are responsible for the defects such as incomplete filling and short shot. From these results, we modified the IC socket and successfully remove the defects. We were also able to find out that the new design socket needs less maintenance cost.

• Journal of the Korean Society for Heat Treatment
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• v.34 no.1
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• pp.17-24
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• 2021

In this study, Ti-X (X=Mn, Fe, Mo) powder alloys were designed and manufactured by both powder metallurgy (PM) and metal powder injection molding (MIM) process to improve strength and formability compared to CP-Ti powder materials. It was found that the lamellar microstructure consisted of α and β phases was formed in PM-processed alloys. However, MIM-processed alloys showed not the lamellar microstucture but the equiaxed α + β microstructure. It was also revealed that the contents of X component and feedstock were not affected to microstructure evolution. The reason why different microstructure was appeared between PM-processed and MIM-processed alloys is not clear yet, but supposed to be the effect of intersticial elements such as C, H and N derived from feedstock during debinding process of MIM.