• Title/Summary/Keyword: Extrusion Die

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Effect of Die and Lubrication in Fine Wire Cold Hydrostatic Extrusion (극세선 냉간 정수압 압출에서 금형과 윤활의 영향)

  • Na K. H.;Park H. J.;Kim S. S.;Yoon D. J.;Choi T. H.;Kim E. Z.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2002.02a
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    • pp.225-230
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    • 2002
  • As in most metal forming processes, die and lubrication are of vital importance in hydrostatic extrusion. An efficient die design and lubrication system selection reduce the pressure required for a given reduction ratio by lowering friction at the billet-die interface. In contrast to the conventional macroscopic extrusion, fine-wire fabrication requires higher extrusion pressure and effect of friction is much more significant. Forming fine Au, Ag, and Cu wire with hydrostatic extrusion process in cold condition, the effect of extrusion die angle, lubrication and billet's initial diameter was studied.

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A Study of the Extrusion Process of Circular Section Products with Helical Fins by Rotating Extrusion Dies (회전압출다이를 이용한 헬리컬 핀붙이 원형단면 압출가공에 관한 연구)

  • Park S. M.;Jin I. T.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.05a
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    • pp.31-34
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    • 2004
  • A new extrusion process of the circular section product with helical fins could be developed by using rotating extrusion dies. The twisting of extruded product is caused by the twisted conical die surface connecting the die entrance section and the die exit section linearly. But, until now, because the process has used fixed extrusion dies, it needs high pressure in order to twist billet and form fin shape on the surface of billet. So, during extruding billet, in order not to twist billet, the extrusion dies is needed to rotate itself instead of twisting billet. And in order to rotate dies, the shape of inside contour of extrusion dies must have conical type with twisted Inclined die surface connecting the die entrance section and the die exit section linearly. The results of experiments show that, in spite of using twisted extrusion dies, twisting of the billet should not happen because of rotating dies in the opposite direction of twisting direction of billet during extruding billet, and, from the results, it shows that it can decrease the power of extrusion pressure and could prevent crack of teeth for fin forming.

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Determination of Welding Pressure in the Porthole Die Extrusion of Improved Al7003 Hollow Section Tubes (포트홀 다이를 이용한 개량된 Al7003 중공압출재의 접합압력결정)

  • Jeong C. S.;Jo H. H.;Kim B. M.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2000.10a
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    • pp.74-77
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    • 2000
  • Porthole die extrusion has a great advantage in the forming of hollow section tubes difficult to produce by conventional extrusion with a mandrel on the stem. Because of the complicated structure of die assembly, extrusion process as a forming of hollow section tubes has been investigated experimentally Therefore, analytic approaches that are useful in profitable die design and in the improvement of productivity are inevitably demanded Welding strength is affected by many parameters, which are such as extrusion ratio, extrusion speed, die shape, porthole number, bearing length, billet temperature and mandrel shape. In this paper, the parameters, which are such as billet temperature, bearing length and tube thickness, are examined. The welding pressures are examined through 3D simulation of non steady state and compared with experimental results.

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Effect of Die Angle in the Hydrostatic Extrusion of Copper-clad Aluminium Composites (Copper-clad Aluminium 복합재료의 정수압 압출시 다이 각이 미치는 효과)

  • 한운용;박훈재;윤덕재;정하국;김승수;김응주;이경엽
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.414-417
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    • 2003
  • A copper-clad aluminium composite bar is lighter and less expressive than a commercial copper alloy bar. Copper-clad aluminium composite bar can be fabricated by hot hydrostatic extrusion process. In this work, the effect of die angle on the compressive properties of copper-clad aluminium composites fabricated using hydrostatic extrusion process was investigated experimentally. The results showed that optimum half die angle was in the range of 40$^{\circ}$ to 50$^{\circ}$ for an extrusion ratio of 19. The results also showed that the half die angle had little influence on the compressive strength of copper-clad aluminium composites. A diffusion layer increased with increasing die angle.

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Extrusion process Analysis and Evaluation of Mechanical property for Micro Multi Cell Tube with 4 hole (4 홀 Micro Multi Cell Tube 의 압출공정 해석 및 기계적 특성 평가)

  • 이정민;김병민
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.397-400
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    • 2004
  • The direct extrusion with porthole die can produce condenser tube which has the competitive power in costs and qualities compared with the existing conform extrusion. In general, porthole die extrusion has a great advantage in the forming that produces the hollow sections difficult to produce by conventional extrusion with a mandrel on the stem. Especially, condenser tube manufactured by porthole die belongs to sophisticated part and demands tighter dimension tolerance and higher surface finish than any other part. In order to confirm the general of porthole die extrusion, we perform the 3D FE analysis of hot porthole extrusion in non-steady state by using DEFORM 3D and investigate a pattern of elastic deformation for porthole die through the stress analysis using ANSYS 5.5 during extrusion process.

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Die stress and Process of Analysis for Condenser Tube Extrusion by using a Porthole Die (포트홀 다이를 이용한 컨덴서 튜브 직접압출 공정해석 및 금형강도 해석)

  • Lee, J. M.;lee, S. K.;Kim, B. M.;Jo, H. H.;Jo, H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.1030-1033
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    • 2002
  • In this study, it is important that we have an understanding of the metal flow for manufacturing condenser tube in porthole die extrusion, because this need to provide for household appliances market that is expected to grow into the major market of the cooling system hereafter. Condenser tube is mainly manufactured by conform exclusion. However, this method was not satisfied a series of the needs for manufacturing condenser tube as compared with porthole die extrusion. The deforming skill recently is required high-productivity, high-accuracy and reducing lead-time, thus it is essential to substitute conform exclusion by porthole die exclusion. Porthole die extrusion has many advantages such as improvement of productivity, reduction of production cost etc. In general, the porthole die extrusion process consists of three stages(dividing, welding and forming stages). In order to obtain the detailed mechanics, to assist in the design of proper die shapes and sizes, and to improve the quality of products, porthole die extrusion should be analyzed in as non-steady state as possible during the entire process to evaluate detailed metal flow, temperature distribution, welding pressure and extrusion lead, and therm stress analysis was practiced to obtain effective stress and elastic deformation value. A analytical results provide useful information the optimal design of the porthole die for condenser tube.

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Influence of Die Geometry on Die-tip Buildup in Plastic Extrusion (플라스틱 파이프 압출시 금형 형상이 다이립 집적에 미치는 영향)

  • 서영성;최선웅
    • Transactions of Materials Processing
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    • v.9 no.5
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    • pp.486-493
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    • 2000
  • Extrusion die-lip buildup has direct and negative impact on the properties of the final product. At the present time there is no absolute method of die-lip prevention. However, a Periodical shut down of extrusion line for the removal has been the general practice throughout the industry in concern. In this study the die-lip buildup was Investigated with a particular attention paid to the influence of die exit geometry and dimensions on the stresses produced at the point of die exit. To demonstrate the relationship between the stress state and the magnitude of the die-lip buildup, a method of virtual manufacturing was performed, assuming elastic-plastic material behavior for the high-density polyethylene under investigation. The overall numerical results suggested that the longer the die-land and/or the smaller the areal reduction of the die would reduce the tendency for the die-lip formation. Similarly, haying a fillet around the circumferential edge of the die exit would be favorable in decreasing the die-lip buildup.

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A Study on Optimal Design Rule for Forward Extrusion Die (냉간 단조용 전방압출금형의 최적구조 설계에 관한 연구)

  • Kim, C.H.;Kim, S.Y.;Kim, J.H.
    • Journal of Power System Engineering
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    • v.3 no.1
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    • pp.45-49
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    • 1999
  • Lots of products are made in various working conditions, depending on the size and the shape of them. Usually, at first, the die for new items had been designed on the basis of experience and know-how, and then modified through trial and error. At a die design stage most of drawings have been drawn manually. Recently some forging companies save design time by repeated utilization of standardized parts with registered data base. In this study the automated die design technique for forward extrusion of axisymmetric products is developed. A standardized die system is proposed from the investigation of ones employed frequently in the metal forming field and the design rules for cold extrusion die. A design example of forward extrusion die is given and discussed.

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Design of Porthole Extrusion Die for Improving the Welding Pressure in Welding Chamber by using the FE Analysis and Taguchi Method (유한요소해석 및 다구찌법을 이용한 접합실 내 접합압력 향상을 위한 포트홀 압출 금형 설계)

  • Lee, S.Y.;Lee, I.K.;Jeong, M.S.;Ko, D.C.;Lee, S.K.
    • Transactions of Materials Processing
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    • v.28 no.6
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    • pp.347-353
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    • 2019
  • The porthole extrusion process is a classic metal forming process to produce complex cross-section shaped aluminum profile. It is very difficult to design porthole die and extrusion process because of the complex shape of extrusion die and internal metal flow. The main variables in this process are ram speed, initial billet and tool temperature, and die shape. In general, the metal flow of porthole extrusion process can be divided into two steps. During the first step, the billet is divided into several parts in the porthole die bridge. During the second step, the divided billets are welded in the welding chamber. In the welding chamber, the level of welding pressure is very important for the quality of the final product. The purpose of this study is to increase the welding pressure in the welding chamber by using a two stage welding chamber. The porthole extrusion die was designed by using the Taguchi method with orthogonal array. The effectiveness of the optimized porthole die was verified by using the finite element analysis.

Investigation on the Description Method of Extrusion Die Surface using NURBS Surface Scheme (NURBS 곡면기법을 이용한 압출금형 곡면의 표현방법에 관한 연구)

  • 유동진;임종훈
    • Transactions of Materials Processing
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    • v.12 no.2
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    • pp.151-160
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    • 2003
  • In the present study, an advanced surface construction method based on NURBS surface scheme is proposed to construct the extrusion die surface. The inlet and outlet profiles we precisely described with NURBS curves using the cubic appropriate control points and weights. The interior control Points of surface are generated using the cubic interpolation of the weights at the inlet and outlet sections. In order to verify of the proposed method, automatic surface generation is carried out for the various types of extrusion die surface.