• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.120-123
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• 2004

The bending phenomenon has been known to be occurred by the difference of velocity at the die exit. The difference of velocity at the die exit section can be obtained by the different velocity of billets inside die chamber after passing the multi-hole container. The curvature can be controlled by the two variables, the one of them is the different velocity of billets through the multi-hole container, the other is the difference of hole diameter. The bending phenomenon during extruding using four billets can be obtained by the difference of hole diameters in the multi-hole container or by the difference of relative velocity of billet inserted in the container. As results of DEFORM-3D analysis, it can be shown that bending can be obtained during extruding by the difference of relative velocity of two billets or by the difference of hole diameter, and the amount of curvature is increased by the difference of velocity and diameter. According to the shape of products, the curvature of rectangular section is bigger than the curvature of regular square section. And, it is estimated that, because the stress on the welding line is much higher than yield stress of material, the bonding of four billets can be obtained.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.371-374
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• 2003

The bending process for the "ㄱ" section product can be developed by the hot metal extrusion machine with the two punches moving in the different velocity. The bending phenomenon can be controlled by difference of velocity at the die exit section by the different velocity of billets through the two-hole container. The results of the experiment show that "ㄱ" section product can be bended by the extrusion process and that the curvature of the product can be controlled by the velocity of punch and that the defects such as the distortion of section and the thickness change of the product and the folding and wrinkling of the product did not happen after the bending processing by the extrusion bending machine.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.337-340
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• 2006

Aluminum extruded profiles have been mostly used only a few automotive parts until now, such as roof rail, sunroof frame and bumper beams. However, Aluminum Extru-form technology, which was recently developed by foreign advanced manufacturer, made it possible to apply the aluminum extruded profiles to suspension parts of passenger and RV cars. It could be obtained by optimized billet casting, extrusion and stretch bending technology. It was possible to have the excellent weight reduction and the competitive price comparing with conventional process of aluminum for automotive parts. Combining additional process technology such as machining and joining, the application can be extended to various automotive parts. We have developed high strength aluminum alloy and fabricated subframe and suspension arm by extruforming process.