Transactions of Materials Processing (소성∙가공)

The Korean Society for Technology of Plasticity and materials processing (한국소성∙가공학회)
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Preform Design Technique by Tracing the Material Deformation Behavior

재료의 변형거동 추적을 통한 예비형상 설계

  • 홍진태 (한국과학기술원 기계공학과) ;
  • 박철현 (한국과학기술원 기계공학과) ;
  • 이석렬 (한국과학기술원 기계공학과) ;
  • 양동열 (한국과학기술원 기계공학과)
  • Published : 2004.10.01
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Abstract

Preform design techniques have been investigated to reduce die wear and forming load and to improve material flow, filling ratio, etc. In hot forging processes, a thin deformed part of a workpiece, known as a flash, is formed in the narrow gap between the upper and lower tools. Although designers make tools that generate a flash intentionally in order to improve flow properties, excessive flash increases die wear and forming load. Therefore, it is necessary to make a preform shape that can reduce the excessive flash without changing flow properties. In this paper, a new preform design technique is proposed to reduce the excessive flash in a metal forging process. After a finite element simulation of the process is carried out with an initial billet, the flow of material in the flash region is traced from the final shape to the initial billet. The region belonging to the flash is then easily found in the initial billet. The finite element simulation is then carried out again with the modified billet from which the selected region has been removed. In several iterations of this technique, the optimal preform shape that minimizes the amount of flash without changing the forgeability can be obtained.

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References

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