• 제목/요약/키워드: Arbitrarily Shaped Product

검색결과 5건 처리시간 0.016초

반용융 알루미늄 합금의 재가열 및 Thixoforging 부품의 기계적 성질 (Reheating of Semi-Solid Aluminum Alloys and Mechanical Properties of Thixoforged Product)

  • 정홍규;강충길
    • 소성∙가공
    • /
    • 제8권5호
    • /
    • pp.437-448
    • /
    • 1999
  • The reheating of the billet in the semi-solid state as quickly and homogeneously as possible is one of the most imposrtant parts. To obtain a fine globular microstructure in cross section of billet, the optimal design of the induction coil for variation of alloys and specimen sizes is necessary. For the thixo-forging process the construction of the reheating data base is very important, because the reheating conditions are different for variation of SSM and billet sizes. So in this study, the optimal coil design of A356 (ALTHIX) and Aι2024 with d×ι=60×90 (mm) to obtain the globular microstructure is theoretically proposed. The suitability of an optimal coil design will be demonstrated by reheating experiments. Finally, the thixoformability of an arbitrarily shaped product is evaluated by its forming variables. The defects and mechanical properties are also investigated.

  • PDF

NURBS 곡면과 면적 사상법을 이용한 압출 금형곡면의 표현 방법에 관한 연구 (Investigation on the Description Method of Extrusion Die Surface using NURBS Surface and Area Mapping Method)

  • 유동진;권혁홍;임종훈
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2003년도 춘계학술대회논문집
    • /
    • pp.343-346
    • /
    • 2003
  • In order to construct the extrusion die surface of arbitrarily shaped sections, an automatic surface construction method based on NURBS surface and area mapping method is proposed in the present work. In the present study, a center point for area mapping is determined by introducing the marring concept based on constant area proportionality between original billet and final product. The characteristic points of inlet profile is determined using the traditional area mapping method and the root finding numerical method. The inlet and outlet profiles are precisely described with NURBS curves using the characteristic points of entry and exit sections. For the construction of NURBS surface, an interpolation method for the pre-determined two section curves has been developed to be used in the generation of interior control points and weights. To show the validity of the proposed method, automatic die surface generation is carried out for the several kinds of shaped sections.

  • PDF

NURBS 곡면과 면적사상법을 이용한 압출 금형 곡면의 표현방법에 관한 연구 (Investigation on the Description Method of Extrusion Die Surface using NURBS Surface and Area Mapping Method)

  • 유동진;권혁홍;임종훈
    • 소성∙가공
    • /
    • 제12권4호
    • /
    • pp.348-357
    • /
    • 2003
  • In order to construct the extrusion die surface of arbitrarily shaped sections, an automatic surface construction method based on NURBS surface and area mapping method is proposed in the present work. A center point fur area mapping is determined by introducing the mapping concept based on constant area proportionality between original billet and final product. The characteristic points of inlet profile are determined using the traditional area mapping method and the root finding numerical method. The inlet and outlet profiles are precisely described with NURBS curves using the characteristic points of entry and exit sections. For the construction of NURBS surface, an interpolation method for the pre-determined two section curves has been developed to be used in the generation of interior control points and weights. To show the validity of the proposed method, automatic die surface generation is carried out for the several kinds of shaped sections.

폴리머 층 전사 및 처짐 현상을 이용한 곡선 형태의 PMMA 나노채널 제작 (Curve-typed PMMA Nanochannel Fabrication using Polymer Layer Transfer and Collapse Technique)

  • 조영학;김성동;황지홍
    • 한국정밀공학회지
    • /
    • 제29권1호
    • /
    • pp.114-120
    • /
    • 2012
  • We present a simple and low-cost method to fabricate poly(methyl-methacrylate) (PMMA) nanochannels with various shapes by combining the standard optical lithography with a PMMA layer transfer and collapse technique. We utilized PMMA membrane reflowing/collapsing phenomena into microchannels to fabricate nanochannels at both corners of arbitrarily-shaped microchannels. This allows nanochannels with various shapes such as curved nanochannels as well as straight nanochannels to be easily fabricated since the shape of the microchannel determines the shape of the nanochannels. This nanochannel fabrication method is simple, flexible, and low-cost since the standard optical lithography with low-resolution optical masks can be used to fabricate nanoscale channels as small as 100 nm wide with various shapes. Also, the sealing of nanochannels can be naturally achieved while the nanochannels are formed through the polymer layer transfer and collapse.

강소성 유한요소법 을 이용한 축대칭 전방 압출 해석 (Rigid-Plastic Finite Element Analysis of Axisymmetric Forward Extrusion)

  • 양동열;오병수;이중홍
    • 대한기계학회논문집
    • /
    • 제9권4호
    • /
    • pp.452-462
    • /
    • 1985
  • 본 논문에서는 금형의 형상과 단면 감소율등이 이에 미치는 영향을 조사하였 다. 이론과의 비교를 위해서 풀림처리된 특수강 소재인 SCM4로 실험을 행하였다. 압출하중은 로드셀(loadcell)로 측정하였으며 수치계산에서 구해진 속도장과 실제속도 장의 차이를 살펴보기 위해서 시편단면에 포토에칭(photoetching)한 압출시킬 시편의 그리드변형을 강소성유한요소법으로 계산한 그리드패턴과 비교 검토하였다.