• Journal of Korea Foundry Society
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• v.16 no.6
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• pp.550-555
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• 1996

A stochastic model, based on the coupling of the finite volume(FV) method for macroscopic heat flow calculation and a two-dimensional cellular automaton(CA) model for treating microstructural evolution was applied-for the prediction of microstructural evolution in squeeze casting. The interfacial heat transfer coefficient at the casting/die interface was evaluated as a function of time using an inverse problem method in order to provide a quantitative simulation of solidification sequences under high pressure. The effects of casting process variables on the formation of solidification grain structures and on the columnar to equiaxed transition of an Al-4.5wt%Cu alloy in squeeze casting were investigated. The calculated solidification grain structures were in good agreement with those obtained experimentally.

• Journal of Korea Foundry Society
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• v.32 no.5
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• pp.225-230
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• 2012

In this study, a more practical and simulation approach which can predict the mechanical properties of aluminum alloys is proposed. First, cooling rate, micro-structure, and mechanical properties of casting product were measured through casting experiment. The relation between cooling rate and SDAS decrease exponentially and the linearly decreasing relation exist between SDAS and mechanical properties. Then, the cooling rate was calculated by casting process simulation and the mechanical properties were predicted by using the relations that were derived through experiment. Experimentally measured mechanical properties and predicted values by simulation were in the range of relatively small difference. The mechanical properties of various Al alloys are expected to be predicted by the casting process simulation before actual casting.

• Journal of Korea Foundry Society
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• v.30 no.1
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• pp.5-13
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• 2010

This article aims to introduce the synchrotron radiation for its utilization in the casting and solidification fields as an unique tool for observation of real time phenomena of molten metal during solidification. General features of the synchrotron radiation were briefly introduced for readers in the casting and solidification fields, with no background regarding to synchrotron radiation. And basic principles of imaging technologies using synchrotron light for in-situ observation of molten metal were explained together with exemplary research works, which were reported on the casting and solidification fields in recent years. As a practical guide, real time observation of Al-Si casting alloy was introduced with experimental facilities, image acquisition, and processing together with representative results.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.3
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• pp.56-59
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• 2005

Aluminum alloy casting is gaining increased acceptance in automotive and electronic industries and especially, squeeze casting is the most efficient method of mass manufacturing of such parts. In this study, the microstructures and mechanical properties of Al-7.0Si-0.4Mg(AC4C) alloy fabricated by squeeze casting process for development of fuel system parts (fuel rail) are investigated. The microstructure of squeeze cast specimen was composed of eutectic structure aluminum solid solution and $Mg_2Si$ precipitates. The tensile strength of as-solid solution treatment Al-7.0Si-0.4Mg alloy was 298.5MPa. It was found that Al-7.0Si-0.4Mg alloy had good corrosion resistance in electrochemical polarization test.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.10
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• pp.77-83
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• 2002

Magnesium alloys casting are gaining increased acceptance in the automotive and electronic industeries and die casting is the most efficient method of manufacturing such mass produced parts. This study has been investigated the microstructures and mechanical properties of Mg-9Al-lZn alloy fabricated by die casting process for development of air bag case. The microstructure of die casted specimen were composed of pro-eutectic magnesium solid solution and $\beta$(Mg17Al12) precipitates. The tensile strength of as-fabricated Mg-9Al-lZn alloy revealed 231.4MPa. It was found that Mg-9Al-lZn alloy have good corrosion resistance in electrochemical polarization test.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.04a
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• pp.30-34
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• 2000

In this paper we analyzed bulging condition which affect the quality of continuous casting steel by using the numerical analytic method. First solidification analyses are performed for each cooling zones. Solidification analysis are carried out by one-dimensuional finite difference method. The bulging deformation of cast slab has been calculated with a two-dimensional elasto-plastic and creep finite element model. The adequacy of the model has been checked against the experimental results. From this study the effects of the process variables such as casting speed cooling condition roll pitch are examined. The results from these analyses would be able to apply to the design of continuous casting process.

• Transactions of Materials Processing
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• v.15 no.8 s.89
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• pp.586-590
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• 2006

42Ni-Fe Invar alloy strips were fabricated using conventional ingot casting and melt drag casting followed by rolling. Mechanical properties such as tensile strength, elongation and blanking deformability of the strips were evaluated. The properties were strongly depended on fabrication methods. Tensile strength and elongation of all strips were in the range of $40-60kg/mm^{2}$ and 26-35%, respectively, which are enough values for the manufacture of the final products. In some of the strips, however, burrs occurred at deformed surface. The properties of strips were explained in terms of microstructure such as grain size and texture formation during rolling. Additionally, strips by melt drag casting method were compared to those by conventional ingot casting.

• Journal of Technologic Dentistry
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• v.25 no.1
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• pp.81-87
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• 2003

Ti-20%Zr-X%Cr(X=0,5) based alloys not containing hamful Al and V were newly designed in order to reveal their possibility for dental casting alloys, and melted in argon-arc casting machine. The mechanical properties were evaluated by using universal testing machine. The tensile strength and %elongaton of the alloys markedly increased with Cr content. The Ti-20%Zr-5%Cr alloy showed a similar tendency with Ti-6%Al-4%V alloy in tensile strength, but surpassed in %elongation. From these results, it was concluded that new alloys for successful dental casting materials should be designed as Ti-Zr-Cr based alloys.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.2
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• pp.361-366
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• 2004

The die casting process was used to manufacture an automotive alternator housing. Generally automobile parts are required to be light and have high strength. The control of casting defects is important but has usually been depended only on the experience of the foundry engineer. Therefore simulations have been carried out on the die casting process of alternator housing. In this paper. we investigated the characteristics of the die casted alternator housing with the HPDC(High Pressure Die Casting) process. We presented the results of filling behavior and solidification process of the cast, The analysis results obtained from the filling behavior and solidification of cast agreed with test results.

• Journal of Korea Foundry Society
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• v.18 no.4
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• pp.373-382
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• 1998

Particulate reinforced aluminum alloys produced by indirect squeeze casting are difficult to shape by cutting or milling. Therefore near net shape forming of complex shapes is of high economic and technical interest. The complex shape products of $SiC_p/6061$ Al composites are fabricated by the melt-stirring and indirect squeeze casting process. The mold temperatures are $200^{\circ}C$ and $300^{\circ}C$ and applied pressures are 70, 100, and 130 MPa. The volume fractions of the reinforcements are in the range of 5 vol% to 15 vol%. The reinforcement dispersion state are observed using on optical microscope. By employing observed results systematically a correlation is demonstrated among the microstructure, particles behavior, mechanical properties and processing parameters for an optimum melt-stirring(compocasting) and indirect squeeze casting process of MMCs. A procedure to establish the optimum squeeze casting of Al-MMCs is proposed.