• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.155-160
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• 2003

It is very important to make an intensive control of burr and surface roughness in the actuator arm of HDD for personal computer. There are two finishing techniques for actuator arm mechanical and chemical method. Centrifugal barrelling and magnetic deburring are mechanical methods, and electrolysis finish is a chemical method. Centrifugal barrelling and magnetic deburring are widely used due to the excellence in convenience and mass production. In this study, characteristics of surface roughness and deburring effect in magnetic deburring and centrifugal barrelling are investigated, and their performance of finishing is compared.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.5
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• pp.831-836
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• 1989

It was found that the effect of the friction between the roll and the workpiece on the spread ratio in flat rolling processes varies with the width-to-height ratio and the reduction in height by Tozawa, Oh and kobayashi numerically. In the present study, the barrelling profile accompanying the width spread was predicted by using the energy method proposed by Kato, which is known to be one of the most advanced method for the three dimensional analysis of the rolling process. The modified velocity field was applied to compute the width spread and the result was verified by experiments. the analysis by the energy method gave the result that the spread ratio increases with the friction factor when the width-to-height ratio is 1 and decreases when the ratio is larger then 2, being consistent with the results of Tozawa and Oh. Nevertheless the cold rolling experiment for pure aluminium showed that the spread ratio decreases with the increasing friction factor irrespective of the width-to-hight ratio.

• Transactions of Materials Processing
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• v.10 no.4
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• pp.294-301
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• 2001

The sensitivity method has been applied to find perform shape that results in the desired shape after foring. As a 2D example, initial shape of specimen for the cylinder shape without barrelling after forging has been found. The method is then applied to various shapes of 3D free forging and initial shapes of the corresponding specimens after forging have been found successfully The sensitivity method is proven to be an effective and accurate tool for the preform design.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.291-296
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• 2000

The sensitivity method has been applied to find perform shape that results in the desired shape after forging. As a basic example, initial shape of specimen for the cylinder shape without barrelling after forging has been found. The method is then applied to various shapes of 3D free forging and initial shapes of the corresponding specimens after forging have been found successfully. The sensitivity method is proven to be an effective and accurate tool for the preform design.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.180-185
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• 2001

The sensitivity method has been applied to find perform shape that results in the desired shape after forging. As a 2D example, initial shape of specimen for the cylinder shape without barrelling after forging has been found. The method is then applied to various shapes of 3D free forging and initial shapes of the corresponding specimens after forging have been found successfully. The sensitivity method is proven to be an effective and accurate tool for the preform design.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.309-314
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• 2000

Rubber is used as a primary suspension component in a vehicle or a mechanical structure. The aim of this study is to establish a procedure for measuring the material properties of rubber and to analyze the differences of material properties of virgin rubber and heat aged rubber. The effect of mechanical conditioning was shown and included in the procedures of tensile. compression. simple shear. and pure shear tests. In addition. using engine oil was recommended for compression test in order not to have barrelling. Moreover, based on the material properties of vil·gin rubber and heat aged rubber. equations of C10 and IRHD were proposed as a function of heat aging temperature and time.