• Transactions of Materials Processing
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• v.8 no.5
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• pp.491-497
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• 1999

The effect of partial squeeze on the quality of casting products in the vacuum die casting was investigated to make defect free casting products with excellent mechanical properties. The partial squeeze and vacuum die casting process was industrially implemented in making reaction shaft support which was made of a hypereutectic Al-15%Si alloy. To combine squeezing and vacuum effects, the plunger injection system was designed and attached on the chill vent type vacuum machinery system. The combination of vacuum effect before injection and partial squeezing effect after injection resulted in defect free die casting products. The uniform distribution of fine eutectic and proeutectic Si obtained from trial process also provided excellent mechanical properties.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.3
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• pp.45-53
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• 2009

Die casting process of Mg alloys for high temperature applications was studied to produce an engine oil pan. The aim of this paper is to evaluate die casting processes of the Aluminium oil pan and in parallel to apply new Mg alloy for die casting the oil pan. Temperature distributions of the die and flow pattern of the alloys in cavity were simulated to diecast a new Mg alloy by the flow simulation software. Dies have to be modified according to material characteristics because melting temperature and heat capacity are different. We changed the shape and position of runner, gate, vent hole and overflow by the simulation results. After several trial and error, oil pans of AE44 and MRI153M Mg alloys are produced successfully without defect. Sleeve filling ratio, cavity filling time and shot speed of die casting machine are important parameter to minimize the defect for die casting Magnesium alloy.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.11
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• pp.74-80
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• 1999

In this study, a stereolithography apparatus (SLA) prototype is used as a master model to be transformed into the silicone pattern by vacuum tool forming. The tool for the first prototype is fabricated by using this silicone pattern. Following this procedure, a temporary tool with metal powder and epoxy for wax injection is prepared for the die set of quick change type which consists of upper and lower base die나 and an insert die. The die set of quick change type appears to be very effective in casting operation by changing tools rapidly. The original wax pattern is formed through the die set, and is made of lost-was. Finally the lost-wax pattern is applied to investment casting. The final casting product is checked regarding its dimensional accuracy.

• Journal of Korea Foundry Society
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• v.13 no.3
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• pp.259-267
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• 1993

The effects of casting processes-direct and indirect squeeze casting, permanent mold casting and die casting on the microstructure and mechanical properties were studied for the hypereutectic B390 aluminium alloy. The effects of T5 and T6 heat treatment were also examined. The direct and indirect squeeze casting showed no casting defects such as porosity and shrinkage were observed in permanent mold castings and die castings. The primary silicon phase was refined and homogeneously distributed in the order of indirect squeeze casting, diecasting, direct squeeze casting and permanent mold casting. Depletion of primary silicon phase in die casting surface was disappeared in indirect squeeze casting. Tensile strength of cast and heat treated specimens were increased in the order of direct squeeze casting, permanent mold casting, indirect squeeze casting and die casting. Hardness of indirect squeeze castings was larger than that of other castings. As indirect squeeze casting of B390 aluminium alloy, the time of T6 heat treatment to achieve high strength can be reduced.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.06b
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• pp.60-66
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• 1998

The horizontal cold chamber pressure die casting produces a variety of net shape, complicate-geometry castings with desired mechanical properties. dimensional tolerance, and surface finish. However, top quality castings can be achieved only when optimal performance of thecold chamber (shot sleeve )and plunger is maintained druing the molten metla injection phase of the process. Unforturately, inreality , shot sleeves deteriorate fast and sometimes fail catastrophically due to incorrect design. These early and unexpected failures of shot sleeves cost die casters money and productiivity. To prevent promature failures of shoe sleeves major faulure mechanisms were investigated. with the aid of analyticla solutions robust design criteria for shot sleeves have been developed. The data directly obtained from failed shot sleeves in the die casting industry for automotive parts, support a strong correlation between design and filures. by applying these design criterial we expected premature faulures of shot sleeves can be avoided in die casting industry.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.2
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• pp.27-35
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• 2006

Al used in automobiles is mostly material, and according to the innovation of technique is in rapid development. Al die casting is an important field as today's trend of lightweight on automobiles. Valve housing in steering system improves driver's controling. The valve housing which is widely reliable to the most automobiles are developed this moment in our automobile industry. Therefore, they are produced by casting method which cost three times or even more expensive in production. If valve housing which is a part of steering system is produced by gravity casting, the space for manufacturing equipment will be increased, and more time and workers would be brought into service. For such reason, die casting would replace gravity casting in order to minimize cost of time, manpower, and working space. This study is the forming analysis of the 2 cavity die casting for automobile valve housing.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.1
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• pp.44-51
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• 2015

When manufacturing die casting mold, generally, the casting layout design should be considered based on the relations of injection system, casting condition, gate system, and cooling system. According to the various relations of the conditions, the location of product defects was differentiated. High-qualified products can be manufactured as those defects are controlled by the proper modifications of die casting mold with keeping the same conditions. In this research, Computer Aided Engineering (CAE) simulation was performed with the several layout designs in order to optimize the casting layout design of an automotive part (Housing). In order to apply them into the production die-casting mold, the simulation results were analyzed and compared carefully. With the filling process, 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. The simulation results were also applied into the production die-casting mold in order to compare the results and verify them with the real casting samples.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.2
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• pp.196-203
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• 2012

When manufacturing die casting mold, generally, the casting layout design should be considered based on the relation between injection system, casting condition, gate system, and cooling system. Also, the extent or the location of product defects were differentiated according to the various relations of the above conditions. High-qualified products can be manufactured as those defects are controled by the proper modifications or the changes of die casting mold with the conditions. In this research, the proper manufacturing method was derived intensively for reducing the defect of the internal porosity of steering wheel housing which is very complicated to achieve a good mold design. The method was also derived for minimizing and for guaranteeing the product quality through the analysis of the casting problem and the deduction of alternative plans.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.813-817
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• 1995

Structural analysis of horizontal cold chamber die casting machine is performed by the FEM. The analyzed model is made up of stationary die platen,movable die platen,link housing platen, C-frame, and tie bar which mainly undertake die locking force and injection force. In modeling, compression gap elements are used for to simulate contacting condition between tie bar and movable die platen, movable die platen and base frame, and link housing and base frame. Unbalanced die locking force imposed on four tie bars are considered. As the results, the deformed shape and the stresses of the die casting machine are given.

• Journal of Korea Foundry Society
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• v.32 no.2
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• pp.65-74
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• 2012

In this paper, we present the results of our studies on optimal die design towards development of a vacuum die casting process to fabricate fuel cell bipolar plate with micro-channel array. Cavity and overflow shape is designed by computational filling analysis of MAGMA soft. Optimal die design consists of seven overflows at the end of cavity and three overflows at each side wall of cavity. The molten metal that passed the gate and reached the side wall flowed into the side overflow, no turbulent flow occurred, and the filling behavior and velocity distribution were uniform. In addition, partially solidified molten metal passing through the channel was perfectly eliminated by overflow without back-flow. When vacuum pressure, injection speed of low and high region was 300 mbar, 0.3 m/s and 2.5 m/s respectively with Silafont 36 die casting alloy, sound sample without casting defects was obtained. The experimental results are nearly consistent with simulation results.