• Journal of Korea Foundry Society
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• v.37 no.6
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• pp.186-192
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• 2017

The lost foam casting method was used to fabricate Al-Si alloy thin sheet specimens; the effects of chemical composition and process variables on the mold filling and mechanical properties were investigated. The mold filling capability was observed to be proportional to the pouring temperature, and both the vibration imposed during the casting and the application of a pattern coating had rather negative effects. The mold filling capability also decreased with the addition of Mg or TiB. When the Mg content increased, the tensile strength of the cast alloy was enhanced, but the elongation decreased. However, after T6 heat treatment, both the strength and the elongation were improved. TiB addition for grain refining or pattern coating did not significantly affect the tensile properties.

• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.43-53
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• 2013

This paper covers the manufacturing process to improve the quality of the puppet for stop-motion films, especially focuses on the mold making and casting process those are the key steps of the puppet making. Unlike the general mold for a duplication, the mold for puppets has special functions to fix an armature and inject casting materials stably inside, and it is repeatedly baked at high temperature. The practical information about puppet makings is provided including various predictable problems, expertise from many professionals, vender list, and so on.

• Journal of Korea Foundry Society
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• v.22 no.3
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• pp.137-143
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• 2002

Silica sand, zircon sand, and steel shots were used as mold packing materials in lost foam casting of the aluminum alloy bar. Vibration acceleration in three directions and temperatures in the casting and mold were measured, and packing and cooling characteristics of these materials were investigated. Packing densities increased with increase in vibration magnitude and time, and were $1.41{\sim}1.49g/cm^2$ for silica sand, $2.54{\sim}2.86g/cm^2$ for zircon sand, and $3.92{\sim}4.52g/cm^2$ for steel shots. Sound castings were obtained only without evacuation of the flask during pouring. Solidification time became faster in order of silica sand, zircon sand and steel shot packing because steel shot has the highest cooling capacity of them. Solidification time of steel shot packing was shortened to about 1/2 of silica sand packing. Cooling capacity of sand mold was generally evaluated by heat diffusivity of the mold, however could be simply evaluated with specific heat per unit volume of the packing material in lost foam casting.

• Journal of the Korean Ceramic Society
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• v.36 no.1
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• pp.89-96
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• 1999

Manufacturing conditions of the porous alumina mold were established to overcome various limits of the gypsum mold. For the preparations of the porous alumina mold, an activated charcoal was added to the Al2O3 with the wt% variation and then mixed. The binary slurry was study dispersed based on the examination of the ESA and rheological behaviro. The cylinder type alumina mold was cast in the gyspum mold and characterized by the shrinkage rate at the variable sintering temperature and the resistance against wear. It was proper to make a sintering of the Al2O3 by the surface diffusion which was non-shrinkage sintering mechansim, and intergranular neck growed stronger while sintering was being made. We studied a sintering by three categories; 1) thermodynamic method below 1,000$^{\circ}C$, 2) kinetic method above 1,000$^{\circ}C$ and 3) combined method. In the results of the respective works, combined method was superiro to the others. The prepared Al2O3 mold had relatively high strength, low drying rate, the resistance against the acid or base and good casting behavior.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.5
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• pp.889-898
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• 2022

In this study, sand casting process was applied to manufacture a large aluminum turbo-type fan used for tank powerpack. To apply the sand casting method, the turbo fan was reverse engineered, and after designing three gating systems, the optimal gating system design was selected by performing casting simulation. In the case of the bottom up-gating system, there is a significant temperature loss of the molten alloy during blade filling. When the molten alloy is completely filled into the sand mold, the blade upper tip and front shroud are below the liquidus temperature. In the case of the top down-gating system, molten alloy scattering occurs, but the temperature loss while the blade is filled is smaller than that of the bottom up type. And after the inflow of molten alloy into the mold is completed, the blade upper tip and front shroud are higher than the liquidus temperature. A sand mold was manufactured with the top down-gating system and the casting process was performed. The fan was made perfectly in appearance without any unfilled parts.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.4
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• pp.71-76
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• 2013

For a die casting mold, generally, the casting layout design should be considered based on the relation among injection system, casting condition, gate system, and cooling system. Also, the extent or the location of product defects was differentiated according to the various relations of the above conditions. In this research, in order to optimize the casting layout design of an automotive Oil Pan_DX2E, Computer Aided Engineering (CAE) simulation was performed with two layout designs by using the simulation software (AnyCasting). The simulation results were analyzed and compared carefully in order to apply them into the production die-casting mold. During the filling process with two models, internal porosities caused by air entrapments were predicted and also compared with the modification of the gate system and overflow. With the solidification analysis, internal porosities occurring during the solidification process were predicted and also compared with the modified gate system.

• Journal of Korea Foundry Society
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• v.27 no.3
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• pp.135-139
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• 2007

To produce higher quality of titanium casting at a lower cost, the new titanium casting technology by using a permanent metal mold was developed and applied to fabricate hip joint for biomedical application. The present study was carried out to investigate the reactivity and fluidity of the Ti-6.0 wt%Al-4.0 wt%V alloy with metal mold by applying various ceramic powders coating on the mold surface. The molten titanium for manufacturing hip joint was poured into steel mold. No reaction layer was formed on the surface of specimens fabricated steel mold coated with $Y_2O_3$ powder.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.1
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• pp.102-113
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• 2000

In this study, a three-dimensional gravity casting problem has been examined to investigate a coupled phenomenon of the filling and solidification process. This work simultaneously considers the two key phenomena of metal casting : the fluid flow during mold filling, and solidification process. The VOF method is used to analyze the free surface flow during filling and the equivalent specific heat method is employed to model the latent heat release during solidification. The time-implicit filling algorithm is applied to save the computational time for analyzing the mold filling process. The three-dimensional benchmark problem used in the MCWASP VII has been solved using both the implicit and explicit algorithm, and the present results are compared with the benchmark experimental results and the other numerical results.

• Journal of Korea Foundry Society
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• v.2 no.2
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• pp.18-30
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• 1982

For the purpose of improving the casting yields of ductile iron castings, the casting conditions for riserlese design were investigated with 150mm cube. As the important casting conditions, chemical composition, pouring temperature, mold rigidity and cooling rate were confirmed. 1. We could obtain the sound castings with the hypereutectic ductile iron. 2. In order to reduce liquid contraction, the pouring temperature should be low as much as possible 3. We could obtain the sound castings through using the rigid mold without mold cavity deformation 4. The modulus of the castings should be 2.5cm one or larger.

• Journal of Korea Foundry Society
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• v.20 no.1
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• pp.3-12
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• 2000

The lead content of drinking water has been restricted to less than 15 ppb by Environmental Protection Agency (EPA) in USA. This has led to extensive research and development work at the Materials Technology Laboratory (MTL) of CANMET, a Canadian Government research laboratory, on the development of low-lead and lead-free copper alloys for plumbing applications. Attentionhas also been focused on the environmentally friendly and energy efficient permanent mold casting process to minimize the disposal of foundry sand contaminated by lead due to the use of leaded alloys in the non-ferrous foundries. A new series of alloys called SeBiLOY contaning Bi and Se been introduced to replace lead in the leaded alloys. This paper addresses some important casting characteristics such as fluidity, hot tear resistance, mechanical properties and microstructure of lead-free alloys such as SeBiLOY III and low-lead alloys such as silicon brass, silicon bronze and yellow brass in gravity permanent mold casting.