• Journal of Intelligence and Information Systems
• /
• v.8 no.1
• /
• pp.159-173
• /
• 2002

The goal of this research is to develop of an intelligent injection mold process planning system using Case-Based Reasoning. Injection mold process planning is the planning of manufacturing process to produce an injection mold economically and efficiently. Automation of the process planning is required because the problems of handmade scheduling, the difficulty of training experts for process planning, the lack of domain experts, the spread of CAD/CAM system and flexible manufacturing. This research uses Case-Based Reasoning because the injection mold process planning is devised variously and complicatedly, but the process planning of similar injection molds is very similar to each other. The system that is developed by this research uses cases that are collected in a case base when planning the process of new injection mold. New injection mold process planning is devised by retrieving a case that was made from the most similar injection mold. This research presented and composed the cases of injection mold process planning, and devised a method of search and adaptation, and developed an intelligent injection mold process planning system with the experimental results.

• Journal of Korea Foundry Society
• /
• v.23 no.3
• /
• pp.137-146
• /
• 2003

The main purpose of this study is to investigate the effects of process parameter on alpha-case formation of Ti and TiAl castings. The previous studies showed that the molten titanium is excessively reactive to the refractory oxide mold, resulting in alpha-caes of the titanium castings regardless of composition of titanium alloys. However, the behavior of the alpha-case formation of TiAl alloy is not consistent with conventional titanium alloy. In order to investigate the alpha-case formation of Ti and TiAl castings with process parameter, especially the associated factors of investment mold such as mold material, binder and mold preheating temperature. An attempt has been made to characterize the alpha-case of titanium casting by using optical microscope, EDS, XRD, EMPA and hardness profiles. The formation of the alpha-case on the surface of pure titanium during investment casting was rather by that of solid solution with metallic element from mold material. The required mold strength was obtained with $CaZrO_3$ because of the possibility of using water soluble binder. However, the separation phenomenon between facing and back-up mold materials should be considered. The interfacial reaction of TiAl alloy showed different behavior from that of pure titanium and $Al_2O_3$ was best mold materials. The effect of binder as well as mold material on the formation of alpha-case was significant.

• Proceedings of the International Microelectronics And Packaging Society Conference
• /
• 2005.09a
• /
• pp.67-88
• /
• 2005

Mold-Flow 3 Die Stack CSP of Mold array packaging with different Gate types. As high density package option such as 3 or 4 die stacking technologies are developed, the major concerning points of mold related qualities such as incomplete mold, exposed wires and wire sweeping issues are increased because of its narrow space between die top and mold surface and higher wiring density. Full 3D rheokinetic simulation of Mold flow for 3 die stacking structure case was done with the rheological parameters acquired from Slit-Die rheometer and DSC of commercial EMC. The center gate showed severe void but corner gate showed relatively better void performance. But in case of wire sweeping related, the center gate type showed less wire sweeping than corner gate types. From the simulation results, corner gate types showed increased velocity, shear stress and mold pressure near the gate and final filling zone. The experimental Case study and the Mold flow simulation showed good agreement on the mold void and wire sweeping related prediction. Full 3D simulation methodologies with proper rheokinetic material characterization by thermal and rheological instruments enable the prediction of micro-scale mold filling behavior in the multi die stacking and other complicated packaging structures for the future application.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.11a
• /
• pp.21-22
• /
• 2023

In order to manufacture high-quality free-form concrete panel (FCP), it is necessary to analyze the limitations of free-form silicone mold (FSM) and conduct technology development research. Currently, the FSM used in FCP manufacture is classified into a side silicon mold(SSM) and a lower silicon mold(LSM). In this study, the limitations of each silicon mold were analyzed and solutions were proposed. In the case of side silicon mold, there is a limit to cannot supporting the side pressure of concrete. Therefore, a mold stacking method was proposed, and at the same time, a process of correcting the movement value of the rod was proposed. In the case of the lower silicon mold, there is a limit to completely implementing the design shape. Therefore, a real-time scanning method and a process of displaying FCP shape coordinates were proposed. The results of this study are expected to be used as basic data for manufacturing high-quality FCP.

• Journal of Korea Foundry Society
• /
• v.26 no.2
• /
• pp.98-103
• /
• 2006

Metal-mold reactions between investment mold and TiAl alloys were investigated for the economic net-shape forming of TiAl alloys. The effect of mold preheating temperatures on the metal-mold reaction were investigated using a vacuum induction-melting furnace. In the case of TiAl alloys, there were no ${\alpha}$-case formation reactions. There were neither interstitial nor substitutional ${\alpha}$-case formations as TiAl alloys have both negligible solubility of oxygen and low activity in molten states. The fluidity of TiAl alloys increases with mold preheating temperature since they have a peritectic reaction that appears in the form of envelope, surrounding each particles of the primary constituent. The results of the investment casting of TiAl alloys confirm that the casting route in our study can be an effective approach for the economic net-shape forming of TiAl alloys.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2008.10a
• /
• pp.439-443
• /
• 2008

Painting process or coating with acrylic film may improve the surface defects of injection molded parts deteriorated by weldlines. flow marks. and etc. However such processes increase the production costs and increase environmental problems. Recently various types of rapid mold heating & cooling technology have been developed in order to improve surface quality of products. In this study. the heating & cooling performance of a telephone case mold is investigated by heat transfer analysis, in which the rapid mold heating & reeling technology is applied. The surface temperature of the mold was measured using thermal image camera and compared with analysis results. The influence of the rapid mold heating & cooling technology on weldline appearance and cycle time increase was also examined.

• Korean Journal of Metals and Materials
• /
• v.49 no.7
• /
• pp.577-582
• /
• 2011

The newly developed ${\alpha}-case$ controlled mold material for Ti investment castings was suggested in this research. The $Al_2O_3$ mold containing interstitial $TiO_2$ and substitutional $Ti_3Al$ was manufactured by the reaction between $Al_2O_3$ and Ti. It is obvious that as the $TiO_2$ and $Ti_3Al$ content in the mold surface were increased, the depth of the interfacial reaction was significantly reduced. In addition, substitutional $Ti_5Si_3$ in the mold surface owing to the reaction between Ti and $SiO_2$ from the binder was effective for ${\alpha}-case$ reduction. Therefore, the ${\alpha}-case$ reduction was accomplished by the diffusion barrier effect of interstitial $TiO_2$, substitutional $Ti_3Al$ and $Ti_5Si_3$.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.32 no.6 s.107
• /
• pp.109-116
• /
• 2005

This study was conducted to examine the growth and physiological characteristics of Asplenium scolopendrium native fern as affected by irrigation times and soil media as an environment modeled on habitate where was sunken-condition. 1. Light intensity was lower in sunken than in non-sunken, but air humidity was higher in sunken about $2040\%$. Soil moisture content was higher with the leaf mold in sunken irrigating 2 times/week. The results of chemical analysis of medium showed that EC, pH, organic matter content, total nitrogen, CEC, Exch-Ca, Exch-Mg and Exch-K were higher with leaf mold than sud: leafmold and field soil: sud: leaf mold. 2. In the case of irrigation 2 times/week Asplenium scolopendrium grew well sunken more than non-sunken. As non-sunken condition similar with, 7 times/week irrigation, plant height, frond width, frond length and stipe length increased. In case of soil media, growth of Asplenium scolopendrium was better with leaf mold than that of sand: leafmold or field soil: sand: leaf mold. 3. In the case of irrigation 2 times/week photosynthetic rate, $CO_2$ absorption rate and water efficiency were higher with non-sunken than that of sunken, expect of stomatal conduction, $CO_2$ use efficiency. The physiological characteristics of Asplenium scolopendrium were highest in non-sunken irrigating 7 times/week In case of soil media, physiological activity was higher with leaf mold than sand: leafmold or field soil: sand: leaf mold.

• Journal of Korea Foundry Society
• /
• v.11 no.1
• /
• pp.44-53
• /
• 1991

The proper feeding conditions for thin Al-Alloy (AA336, JIS AC8A) castings in permanent mold were investigated to eliminate microshrinkage porosity. 5mm-thick plates (200mm long, 60mm wide) were cast with increasing padding taper from 0 to 5% under different conditions : (1) constant mold temperature of $350^{\circ}C$, (2) continuous production with uniform mold thickness (10mm), (3) continuous production with a negative taper of 2.5% in mold thickness (thickness decreasing in direction to riser). The test casting were machined off to the midplane and the shrinkage porosity was examined visually. The critical padding taper which can just eliminate the shrinkage porosity was determined for each condition, i.e. : (1) 4.5% at the constant mold temperature, (2) 3.5% for continuous production with the uniform mold thickness (3) 1.5% for continuous production with the taper in mold thickness. A computer simulation by a finite difference analysis program was applied to the test casting. The liquid fraction gradient (LFG) and the temperature gradient divided by the square root of the cooling rate (G /SR) were calculated at the end of solidification and compared with the shrinkage porosity area in the castings. For the case of constant mold temperature, LFG is a better parameter to predict shrinkage porosity than G /SR and its critical value is around 11%/cm. But for the case of continuous production, neither LFG nor G /SR could be a reliable parameter. The experimental results about the critical padding taper are of practical interest for designing permanent molds and castings. The computer simulation results stimulate further research to be directed on the prediction of centerline microshrinkage porosity in continuous production.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.638-641
• /
• 1995

The model-technology has been conduced to a large quantity of automobile and electric products. However, many problems in mold-technology have been solved through trial and error of experts. So it has given rise to overdesign of mold and generated other problems in production line. In this paper we choosed the lower-mold of a cool chamber in refrigerator as the model of the study and mass reduced overdesigned mold. In mass reduction process, several cases in plane processing error were selected for the sample case through FEM analysis & simplicated theory analysis and each case was evaluated for mass reduction.