• Journal of Powder Materials
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• v.8 no.2
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• pp.136-139
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• 2001

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.04a
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• pp.1-10
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• 2002

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.06a
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• pp.57-72
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• 2000

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.06a
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• pp.39-52
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• 2001

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.06a
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• pp.139-146
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• 2001

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.09a
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• pp.164-174
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• 2005

• Proceedings of the KAIS Fall Conference
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• 2000.04a
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• pp.12-12
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• 2000

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.4
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• pp.333-339
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• 2008

Densification behavior of copper powder was investigated to study the effect of an aluminum mold under warm pressing. The low flow stress of an aluminum mold is appropriate to apply hydrostatic stress to powder compacts during compaction under high temperature. The suggested powder metallurgy process is very useful under high temperature since copper powder compacts have higher relative density over axial stress of 100 MPa and show more homogeneity as compared with conventional warm pressing. Elastoplastic constitutive equation proposed by Shima and Oyane was implemented into a finite element program (ABAQUS) for densification behavior under warn pressing by using a metal mold. Finite element results agreed well with experimental data for densification and deformation of copper powder compacts in the mold.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.7
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• pp.36-43
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• 2003

In this paper, the warm forging process sequence has been determined to manufacture the warm forged product for the precision bevel gear used as the differential gear unit of a commercial automobile. The preform shape of bevel gear influences the dimensional accuracy and stiffness of final product. So, the design parameters related preform shape such as aspect ratio and chamfer length having an influence the formability of forged product are analyzed. Then the optimal conditions of design parameters have been selected by artificial neural network (ANN). Finally, to verify the optimal preform shape, the experiments of the warm forging of the bevel gear have been executed. The proposed method can give more systematic and economically feasible means for designing preform shape in metal forming process.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.507-512
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• 2003

A finite element analysis for near-net-shape forming of Al6061 powder was performed under warm pressing. The advantages of warm compaction by rubber isostatic pressing were discussed to obtain parts with better density distributions. To simulate densification and deformed shape of a powder compact during warm pressing, the elastoplastic constitutive equation based on yield function of Shima-Oyane was implemented into a finite element program(ABAQUS). The hyperelastic constitutive equation based on the Ogden strain energy potential was employed to analyze nonlinear elastic response of rubber. Finite element results were compared with experimental data for Al6061 powder compacts under warm pressing.